| File Name: | toyota aurion navigation system manual.pdf |
| Size: | 3159 KB |
| Type: | PDF, ePub, eBook, fb2, mobi, txt, doc, rtf, djvu |
| Category: | Book |
| Uploaded | 26 May 2019, 23:30 PM |
| Interface | English |
| Rating | 4.6/5 from 819 votes |
| Status | AVAILABLE |
| Last checked | 19 Minutes ago! |
The construction and opera-tion of the K-Jetronic (CIS) feu l injection system is When installing the mixture control unit, tighten thedifferent from other feu l injection systems. The fastening screws uniforml.ytechnical instruction booklet Fuel Injection - Con-tinou us Injection System (CIS) at the back of the Whenever work is performed on the feu l injectionmanual describes the components and operation of system, the idle and CO msu t be adjusted.the K-Jetronic feu l injection ssy tem in detail. Athorough understanding of the variosu compo- How to su e this manau l. Use the trobu le-shootingnents is required before working on K-Jetronic fuel chart to find the casu e(s) for a giev n smy ptom. Thesystems. casu e colmu n will indicate what component(s) should be tested. Each component test instrcu tion isBefore trobu le-shooting, testing or adjsu ting the a complete instrcu tion. One component may beK-Jetronic feu l injection system, the ignition sys- checked by folloiw ng the test instrcu tions for thetem and the mechanical system of the engine specific component, or the entire ssy tem can be(compression, av lev timing, etc.) must be iw thin checked by folloiw ng all the component instructionsspecification and operating properly. Verify that in order.these systems are in proper ow rking order beforeproceeding fru ther. The Tool List and Component Location sections will help identify the necessary tools and help locateK-Jetronic fuel ssy tems have an electric safety ev hicle components to be tested. Specific compo-circuit hw ich prevents the electric feu l pmu p and nent remoav l and installation information can beother electrical devices from operating unless the fonu d in Mounting the Pressru e Tester and Com-engine is running or being started.
The electric ponent Repair The Electric Wiring Diagram sectionsafety circiu t can be bridged to apply voltage to any shosw how to bridge the electric safety circuit toelectrical component iw thotu rnu ning or starting apply voltage to electrical components iw thotu rnu -the engine. This procedru e can be found in the ning the engine. Replacement parts lists and com-Electric Wiring Diagram section of the manau l.After starting, the valevopens by means of an electric heating element.Several component tests (Axiu liary Air Valve andWarm-up Regulator) reqiu re that the engine is cold.For cold tests, the engine msu t not have been runfor several hours, preferably overnight.Most ev hicles since 1978 have fuel distributorshw ich su e psu h valev s in the system pressru eregulator to maintain pressru e. Several componenttests require special testing procedures for feu ldistribtu ors with push av lves. The Fuel Pump sec-tion describes in detail how to identify a fuel dis-tributor iw th a push valve in the ssy tem pressru eregulator.Thorogu hly clean the fuel fittings before removingany fuel lines. Dirt must not enter the fuel systemunder any circumstances. Do NOT bend the steelfeu l lines. The Start Valev is located on backof intake manifold below the venturi assembly.Electric feu l pmu p not operating (see Fuel Pmu p) Defectiev cold start ssy tem (see Cold Start Ssy tem) Leaking cold start av lve (see Cold Start System) Incorrect cold control pressru e (see Warm-pu Regulator) Warm control pressru e too high (see Warm-pu Regulator) No. Any air dranw into the engine withotu passing through the air flow sensor iw ll casu e a lean air-feu l mixture condition and improper engine operation. To test for air leaks, remoev the otu let hose from the auxiliary air valev and pressurize the hose with com- pressed air. Hold the throttle plate open and coat all air fittings (arrosw below) with soapy aw ter. Bbu bles indicate a leak. Remoev the rubber boot from the air flow sensor.
Bridge the electric safety circuit (see Electric Wiring Diagram). Switch the igni- tion on for 10 seconds to apply control pressru e to the plunger. Fully lift the sensor plate pu by hand to its maximmu deflection as shown. Even resistance must be felt over the entire leev r moev ment. If not, the air flow sensor plate is not moiv ng freel,y (see belo)w. Now psu h the sensor plate donw rapidly, almost back to its rest position. The plunger will not follow the rapidly moiv ng sensor plate, btu the shock of the plunger hitting the sensor plate lever when it does come donw must be felt. If this cannot be felt, the plnu ger is not moiv ng freel,y (see belo)w. Flu ly lift the air flow sensor plate up to its maix mmu deflection. When released, the sensor plate must fall back to its rest position after bouncing once or twice on the spring stop. If not, the air flow sensor plate is not moiv ng freel,y (see below). If the air flow sensor plate does not move freely, loosen the monu ting screws aronu d the air flow sensor hosu ing to check if hosu ing aw rpage is casu - ing the lever to bind. If necessary, replace the gasket nu der the air flow sensor and nu iformly tighten the fastening scresw. If the plnu ger does not moev freel,y remove the fuel distributor from the air flow sensor (see Feu l Dis- tributor Repair). Remove the plnu ger from the fuel distribtu or. If it is necessary to blow compressed air in the control pressure connection hole to free the plunger, hold the plnu ger with yoru hand as shown to prevent the plnu ger from falling otu of the fuel dis- tributor. Clean the plnu geriw th an appropriate solev nt. If the plunger still binds in its barrel, replace the fuel distribtu or.12 ROBERT BOSCH Porsche K-Jetronic Air Flow Sensor Plate Position. The sensor plate must be flat and pass through the narroew st part of the funnel without touching the sides. If the sensor plate touches the sides of the funnel, loosen the sensor plate fastening screw.
Hold the fasten- ing screw iw th pliers to preev nt the plate from moving donw as shown. When the giu de ring is in place, tighten the fastening screw to 5.0 - 5.5 Nm (3.7 - 4.0 ft Ibs). Then, loosen the screw and retorqeu the fasten- ing screw again to the same value. The air flow sensor plate msu t not now be able to be turned by hand. Bridge the electric safety circiu t (see Electric Wiring Diagram). Siw tch the ignition on for 10 seconds to apply control pressure to the plnu ger. The upper edge of the sensor plate should be flush with the beginning of the upper cone as shonw. The upper edge of the sensor plate may be as much as 0.5 mm below the beginning of the pu per cone, btu must NOT project up into the cone at all. Adjust the sensor plate position by removing the air filter and bending the iw re loop on the spring stop (arro)w or turning the adjusting screw (1). Remoev the air filter from the air flow sensor. Siw tch the ignition on for 10 seconds to apply control pressure to the plunger. Flu ly push the sensor plate donw by hand to its maix mmu deflection as shonw. Eev n resistance must be felt over the entire lever moev ment. If not, the air flow sensor plate is not moving freely, (see belo)w. Now pull the sensor plate up rapidl,y almost back to its rest position. The plunger iw ll not follow the rapidly moiv ng sensor plate, btu the shock of the plnu ger hitting the sensor plate leev r when it does come donw must be felt. If this cannot be felt, the plunger is not moving freel,y (see belo)w. Fully psu h the air flow sensor plate down to its maix mum deflection. When released, the sensor plate msu t fall back to its rest position after bonu cing once or tiw ce on the spring stop. If not, the air flow sensor plate is not moiv ng freely, (see belo)w. If the air flow sensor plate does not moev freel,y loosen the monu ting screws aronu d the air flow sensor housing to check if hosu ing warpage is casu - ing the lever to bind.
If necessary, replace the gasket nu der the air flow sensor and nu iformly tighten the fastening screws. If the plunger does not moev freel,y remove the feu l distribtu or from the air flow sensor (see Fuel Dis- tributor Repair). If it is necessary to blow compressed air in the control pressru e connection hole to free the plunger, hold the plnu ger with oy ur hand as shown to preev nt the plunger from falling out of the fuel dis- tribtu or. Clean the plnu ger with an appropriate solev nt. If the plunger still binds in its barrel, replace the feu l distribtu or.14 ROBERT BOSCH Porsche K-Jetronic Air Flow Sensor Plate Position. Remove the air filter KNW4from the air flow sensor. The sensor plate must beflat. The chamfered edge of the sensor plate must facedonw. The word 'top' or fiev pnu ch marks arestamped on the top of the sensor plate.The sensor plate msu t pass throgu h the narrowestpart of the fnu nel iw thout tocu hing the sides. If thesensor plate tocu hes the sides of the fnu nel, loosenthe sensor plate fastening screw. Hold the fastening screwas shonw to prevent the sensor plate from movingdonw. When the guide ring is in place, tighten thefastening screw to 5.0 - 5.5 Nm (3.7 - 4.0 ft Ibs). Then,loosen the screw and retorqeu to the same valeu. Theair flow sensor plate msu t not now be able to beturned by hand.Bridge the electric safety circiu t (see Electric WiringDiagram). Switch the ignition on for 10 seconds toapply control pressru e to the plnu ger.The pu per edge of the sensor plate should be flsu hwith the beginning of the pu per cone as shonw. Theupper edge of the sensor plate may project pu asmcu h as 0.5 mm aboev the beginning of the pu percone, but the loew r edge of the sensor plate (abovethe chamfer) msu t not project donw into the lowercone at all.If the sensor plate is too high, ev ry carefully tap theguide pin (arrow) deeper into the hosu ing. Catu ion:Make this adjsu tment very carefully.
Adjsu tment se-veral times in both directions will loosen the press fit ofthe pin, possibly casu ing engine damage.K-Jetronic Porsche ROBERT BOSCH 15 AUXILIARY AIR VALVE Cold Operation. Test the axiu liary air valve first iw th the engine cold (not rnu for several horu s, preferably oev rnight). Disconnect the electric plgu from the axu- iliary air valve and from the aw rm-up regulator. Re- moev both air hoses from the auxiliary air valve. Using a flashlight and a mirror, look through the valve as shown. When the engine is cold, the av lev must be open. If not, replace the axuiliary air valve. Warm Operation. Attach the electric plgu to the auxil- iary air valve. Turn the ignition on. The auix liary air av lve must be completely closed iw thin 10 mintu es. If the axuiliary air valve does not completely close iw thin 10 mintu es, test the supply voltage (approxi- mately 11.5 volts, ignition off) aav ilable to the axuil- iary air valve at the electric plgu. Fuel distribtu ors WITH push av lev s (most ev hicles since 1978) have tow fuel lines connecting with the aw rm-up regulator. Determine whether the ev hicle to be tested is fitted with or without a psu h av lev before proceeding fru ther. Disconnect the retru n feu l line leading to the gas tank at the appropriate test point, as indicated below for the specific vehicle. Test Point for 911: Disconnect the nu ion fitting on the fuel retru n line from the fuel distribtu or (see Compo- nent Location). Connect a temporary hose with an appropriate fitting (M 14 x 1.5) to the line coming from the fuel distribtu or. Test Point for 924: Clean and disconnect the nu ion fitting located aboev the front alx e (see Component Location). Test Point for 928: Disconnect the fuel line from the fuel distribtu or which leads to the gas tank (see Component Location). Connect a temporary fuel line iw th an appropriate fitting (M 14 x 1.5) to the otu let on the fuel distributor.
Hold the line coming from the feu l distributor in a Fuel Pump Test Point WITHOUT Psu h Valev1500 cc or larger gradau te. Infleix ble metal feu l linesmay require a rubber hose to reach the gradau te.Remove the electric plgu from the warm-up regulatorand the aiux liary air valev. Bridge the electric safetycircuit (see Electric Wiring Diagram).Tru n the ignition on for the amount of time specifiedfor Fuel Pump on the test sheet.If fuel qau ntity is not iw thin specification, check forsufficient ov ltage spu ply to the fuel pump (minimmu11.5 ov lts) or a dirty fuel filter. If all the above aresatisfactor,y replace the electric fuel pump.K-Jetronic Porsche ROBERT BOSCH 17 COLD START SYSTEM Thermo-Time Switch. This instruction applies only to Robert Bosch thermo-time siw tches. Remoev the thermo-time switch from the engine. Engine coolent will spill otu when the switch is re- moev d from the engine. Find the design nmu ber stamped on the flats of the thermo-time siw tch hous- ing. Use the design number to find the appropriate test values from the thermo-time switch chart below. Using an ohmmeter, check the resistance at both.Use aw rm water to heat the switch as required. If any resistance does not fall iw thin the specified tolerance, replace the thermo-time siw tch. Disconnect the electric plgu from the cold start valve. Remoev the cold start valve from the intake manifold. Hold the cold start av lve in a graduate. A rubber hose may be required to reach the gradau te. Tru n the ignition on for not more than 30 seconds. If the cold start valve does not spray, replace the cold start av lev. Tru n the ignition off and disconnect the temporary electrical wires from the cold start valev. Wipe the cold start av lve dry. With the electric safety circiu t still bridged, siw tch the ignition on for one mintu e. If the cold start valve drips or leaks, replace the cold start valve.
18 ROBERT BOSCH Porsche K-Jetronic WARM-UP REGULATOR (CONTROL to pressure gagu ePRESSURE) fPorsche su es seev ral warm-pu regulators on its ev hi- to warm-up KDEP 1034 fcles. The testing procedure and test specifications are reglu atordifferent for each type of aw rm-pu reglu ator. Find the from feu law rm-pu reglu ator type to be tested from the ones distributorlisted below and proceed iw th the test instructions forthat specific tpy e. Opening Both Valev Scresw (measuring control pressure)Standard Warm-Up Regulator. Connect pressure tes-ter KDEP 1034 (see Mounting Pressure Tester). Usethe test specification for the specific aw rm-pu reg-ulator.Cold Control Pressru e: The engine msu t be cold (notrnu for seev ral horu s, preferably overnight). Discon-nect the plug from the warm-up regulator. Open bothvalve screws on the three-aw y valve of the pressru etester. Bridge the safety circiu t (see Electric WiringDiagram).Siw tch the ignition on to rnu the electric feu l pumpand read the cold control pressru e on the gagu e. Thepressure must be iw thin the tolerance band giev n onthe appropriate test specification graph. Tru n theignition off.Warm Control Pressure: Engine temperature is notimportant. Attach the plgu to the warm-pu regulator.Bridge the safety circiu t. Open both av lev scresw onthe pressure tester as shonw.Switch the ignition on to operate the electric fuelpmu p. When the pressru e stops increasing, readwarm control pressru e on the gagu e. The warmcontrol pressure msu t be within the tolerance giev non the test sheet. Turn the ignition off.If the warm control pressru e does not fall iw thin thespecified tolerance, test the spu ply ov ltage (approix -mately 14 ov lts) available to the aw rm-up reglu ator.If sfu ficient ov ltage is aav ilable to the aw rm-up reg-ulator, and the aw rm control pressure still does notfall within the specified tolerance, replace the warm-pu regulator.
K-Jetronic Porsche ROBERT BOSCH 19 Warm-Up Reglu ator iw th Flu l Load Enrichment. Con-,e!P Vacum nect pressure tester KDEP 1034 (see Monu ting Pres- sru e Tester). Use the test specification for the specific 43 Atmosphere aw rm-up regulator. Cold Control Pressure: The engine msu t be cold (not run for several hours, preferably overnight) nu less otherwise indicated on the test sheet. Disconnect the plug from the warm-up reglu ator. Open both valev screws on the three-aw y av lve of the pressru e tester. Bridge the safety circuit (see Electric Wiring Diagram). Siw tch the ignition on to run the electric fuel pump. Apply the vacum indicated on the test sheet (if an)y to the aw rm-pu regulator with a av cum pmu p as shown. The cold control pressru e indicated on the gagu e must be iw thin the tolerance band shown on the appropriate test specification graph. Tru n the igni- tion off. Warm Control Pressure: Test warm control pressure with the aw rm-pu regulator plug attached. Engine temperatru e is not important. Bridge the safety cir- ciu t. Open both av lev scresw on the pressru e tester as shonw. Siw tch the ignition on to rnu the electric fuel pmu p. Apply the vacmu indicated on the test sheet (if an)y to the warm-pu regulator with a vacum pmu p as shown. When the pressru e stops increasing, read the aw rm control pressure on the gauge. The warm control pressure msu t be within the tolerance giev n on the test sheet. Turn the ignition off. Warm Control Pressru e WITH Throttle Activated Valev: Test warm control pressure with the warm-pu reglu ator plgu attached. Position throttle plate against idle stop. Switch the ignition on to rnu the electric fuel pmu p. When the pressure stops increasing, read the warm control pressure on the gauge. If the aw rm control pressru e is not within the tolerance giev n for idle on the test sheet, remove both fastening scresw on the throttle activated av lve and tru n the av lev in the area of the slots.
If the idle value cannot be obtained, replace the throttle activated av lve and readjust to the valeu given for idle on the test sheet. Position the throttle plate by hand abotu halfway. If the pressru e does not rise to the partial load valeu giev n on the test sheet, replace the warm-pu reg- ulator. Completely open the throttle to the flu l load position. If the pressru e does not drop to the flu l load av lue giev n on the test sheet, replace the throttle activated av lev and recheck the idle pressru e. If the aw rm control pressure does not fall iw thin the specified tolerance, test the supply ov ltage (approxi- mately 14 ov lts) aav ilable to the warm-up reglu ator. If sufficient ov ltage is available to the aw rm-pu reg- lu ator, and the warm control pressure still does not20 ROBERT BOSCH Porsche K-Jetronic fall iw thin the specified tolerance, check the vacmu to pressure gagu esoru ce for a leak.F 1:Warm-Up Regulator with Flu l Load and Altitude 2Compensator. Connect pressru e tester KDEP 1034(see Monu ting Pressru e Tester). Use the test specifica- to warm-up 1O O3 ftion for the specific aw rm-up regulator.Disconnect the Opening Both Valve Screwsplug from the aw rm-up reglu ator. Open both av lev (measru ing control pressure)scresw on the three-aw y valve of the pressure tester.Bridge the safety circiu t (see Electric Wiring Diagram).Siw tch the ignition on to run the electric fuel pmu p.Apply the av cum indicated on the test sheet (if an)yto the warm-pu reglu ator iw th a vacmu pump asshonw. The cold control pressru e indicated on thegauge msu t be iw thin the tolerance band shown onthe appropriate test specification graph. Tru n theignition off.Warm Control Pressure: Test warm control pressurewith the aw rm-up regulator plgu attached and theengine aw rm. Use station pressure from the localairport or weather bru ea,u NOT the correctedbarometric pressru e reported to the public, hw enreading the warm control pressru e graph on the testsheet.
Bridge the safety circuit. Open both valvescresw on the pressure tester as shonw.Siw tch the ignition on to run the electric fuel pmu p.Apply the vacum indicated on the test sheet (if any)to the warm-pu regulator with a vacum pump asshonw. When the pressure stops increasing, read thewarm control pressure on the gagu e. The warmcontrol pressru e msu t be iw thin the tolerance giev non the test sheet (use upper curve hw en testing WITHvacum). Tru n ignition off.If the aw rm control pressru e does not fall within thespecified tolerance, test the supply voltage (approxi-mately 14 volts) available to the aw rm-pu reglu ator.If sfu ficient ov ltage is available to the aw rm-up reg-ulator, and the warm control pressure still does notfall within the specified tolerance, check the av cumsoru ce for a leak.If the high control pressures required for high al-titdu es cannot be obtained, increase ssy tem pressureto the high side of the tolerance band (see SystemPressru e).If warm control pressru e cannot be brogu ht intospecification, replace the aw rm-pu regulator.K-Jetronic Porsche ROBERT BOSCH 21 to pressru e gagu e SYSTEM PRESSURE 2 Testing Ssy tem Pressure. Engine temperature is not important. Connect pressure tester KDEP 1034 as r indicated in Monu ting Pressru e Tester. Bridge the electric safety circiu t (see Electric Wiring Diagram).f J from fuel Close the pressure tester valev screw leading to the to aw rm-up KDEP 1034 distributor warm-up reglu ator as shown.Read the ssy tem pressure on theClosing Valev Screw to Warm-pu Reglu ator gauge and compare this reading with the av leu (measuring ssy tem pressure) shonw on the test sheet.SYSTEM PRESSURE REGULATOR If system pressru e is lower than the av leu giev n on (iw thout psu h av lev ) the test sheet, test the feu l pmu p. If the fuel pmu p is iw thin specification, adjsu t the system pressru e as indicated below.
If system pressure is higher than the av leu shown on the test sheet, check the gas tank return line for a restriction. If there is no restriction in the return line, adjust the system pressru e. Adjusting System Pressure. If the fuel distribtu or is fitted WITH a psu h av lve, unscrew the large screw plug iw th attached psu h valev assembly. Change the adjusting shim as reqiu red. A 0.1 mm increase in shim thickness will increase system pressure 0.15 bar (2.2 PSI). Use a new O-ring and copper gasket when reinstalling the large screw plgu and psu h av lev. Note: The piston in front of the shim is matched to the hosu ing and is not replaceable. If the fuel distribtu or is fitted WITHOUT a psu h av lve, remove the screw plug and change the adjsu ting shim as required. A 0.1 mm increase in shim thickness iw ll increase system pressru e 0.15 bar (2.2 PSI). Use a new copper gasket hw en installing the screw plug. Tighten the screw plgu to 13 - 15 Nm (10 - 11 ft Ibs). Connect fpressru e tester KDEP 1034 (see Monu ting PressureTester). Bridge the electric safety circuit (see Electric r fWiring Diagram). Open both av lev screws on thethree-aw y av lev as shown. 1 O O3 from feu l distribtu orTru n the ignition on. When warm control pressru e is to warm-up KDEP 1034reached, tru n the ignition off. After the specified time, reglu atorthe control pressure must NOT be less than the av luegiven on the test sheet for leakage test. If control Opening Both Valev Screswpressru e drops too qiu ckly, close the valve leading to (measuring control pressru e)the aw rm-up regulator and repeat the leakage test.Check the cold KDEP 1034start av lve for leakage (see Cold Start Valev ). Test theinjectors for leakage (see Testing Injectors). Connect eachinjector to valev tester KDJE 7452 as indicated in theoperating instrcu tions included with the tester. Injec-tors sholu d be tested for opening pressure, leakageand spray pattern. Replace any defective injectors.
K-Jetronic Porsche ROBERT BOSCH 23 COMPARATIVE TEST Setting up the tester. Comparative tester KDJE 7451 is used to measru e eqau l deliev ry between injectors. The comparatiev test iw ll also determine whether a problem inov lev s an injector or the feu l distribtu or. Set the tester on a solid surface next to the vehicle. Level the tester and install the retru n hose in the gas tank. Remoev the injectors from the engine and insert each injector, in order, into the tester feu l lines. Tighten the knurled copu ling to secure each injector. Remove the rubber boot (pu draft) or air filter (downdraft) from the upper part of the air flow sensor. Siw tch the ignition on to operate the fuel pmu p. Move the sensor plate to its maximum deflection. Press each of the eight buttons while turning the load range knob back and forth until the rotameter tubes are completely bled. Retru n the sensor plate to its rest position. Idle Test. Tru n the load range knob to the left to read the left rotameter tbu e. Press btu ton nmu ber 1. Moev the air flow sensor plate by hand nu til the left rotameter tube shosw the av lue giev n for setting point on the Idle Deliev ry Chart. Fix the sensor plate in this position. Push each button one after the other until the lowest delivery is obtained and then readjsu t the sensor plate to the setting point av lue. Push each button again. Eev ry injector must now be iw thin the tolerance giev n for deliev ry on the Idle Deliev ry Chart. If not, see Test Results below. Tru n the load range knob to the right to read the right rotameter tbu e. Moev the sensor plate by hand nu til the right rotameter tbu e shows the valeu giev n for setting point on the Part Load Delivery Chart. Psu h each button until the loew st delivery is obtained and then readjust the sensor plate to the setting point av lue. Push each btu ton again. Every injector msu t now be within the tolerance giev n for delivery on the Part Load Delivery Chart.
Push each button nu til the highest deliev ryis obtained and then readjsu t the sensor plate nu tilthe rotameter tube reads the next lower setting pointav lue on the Flu l Load Deliev ry Chart.Push each btu ton again. Eev ry injector must be withinthe appropriate tolerance given for delivery on theFlu l Load Deliev ry Chart. Pressure tester KDEP 1034 msu t be re- screw moev d from the vehicle. The electric safety circiu t msu t NOT be bridged. The engine must be aw rm. IfADJUSTING SCREWS any fuel lines haev been opened, warm the engine nu der load to purge the lines of air. Idle speed and CO specifications are given on the emissions decal in the vehicle engine compartment. Vehicles with Secondary Air Pump: Remoev and plug the pressure hose on the air pump. Idle Speed Adjsu tment. Turn the idle bpy ass screw (arro)w to adjust idle speed. CO Adjsu tment. Make the CO adjsu tment im- mediately after a test drive (engine at operating tem- perature). Install the CO sensor in the tailpipe. Re- moev the sealing plug from the air flow sensor hous- ing. Using wrench KDEP 1035, tru n the CO mixtru e screw out (counterclockwise) to a valeu leaner than specification. Then, turn the mixture screw in (clockiw se) to bring the CO value into specification. Alaw sy adjust from the lean side when setting CO. After each adjustment, remove the rw ench and accel- erate the engine to stabilize the mixture. The CO av leu msu t now be less than 1%. If not, clean the air filter on the secondary air pmu p with compressed air. Install the plgu in the air flow sensor housing and install the av cmu limiter air hose (if fitted). Testing Throttle Activated Valev. The 1973-74 911S uses a throttle activated av lve to energize the start av lve. Test the valve by attaching an ohmmeter to the two electrical connections on the throttle activated av lev. In the idle position, the ohmmeter must read infinity (circuit open).
When the hand throttle (betew en the seats) is plu led all the way otu, the ohmmeter msu t read ez ro resistance (circiu t closed). If not, adjsu t the throttle actiav ted valve. Adjusting Throttle Actiav ted Valve. Insert a 2 mm thick feeler gagu e betew en the idle stop screw and the stop boss. Holding the stop screw against the feeler gagu e, turn the stop screw until the throttle circiu t just closes (ez ro resistance on the ohmmeter). It must be possible to press the throttle activated av lve switch leev r a minimmu of 0.5 mm farther downward. Then check again that the electric circiu t is closed (zero resistance) hw en the hand throttle lever is fully plu led.26 ROBERT BOSCH Porsche K-Jetronic IDLE SPEED AND CO ADJUSTMENT (911 since 1976) Preparation. Pressure tester KDEP 1034 msu t be re- moev d from the vehicle. The electric safety circiu t must NOT be bridged. If any feu l lines haev been opened, aw rm the engine under load to purge the lines of air. Idle speed and CO specifications are giev n on the emissions decal in the ev hicle engine compartment. On 911SC models, make sru e the oil tank coev r is sealing properly. A leaking oil tank coev r will allow unmetered intake air to enter the engine. Vehicles with Secondary Air Pump: Remoev and plgu the hose on the secondary air pump check valve as shown. Vehicles iw th Vacum Limiter. Turn the idle bypass screw (arro)w to adjust idle speed. CO Adjsu tment Install the CO sensor in the tailpipe. If the vehicle has a catalytic converter, install the sensor in the screw plgu hole ahead of the converter. This hole msu t be sealed around the sensor when reading the CO meter. Remove the sealing plgu from the air flow sensor housing. Using rw ench KDEP 1035 as shown below, tru n the CO mitx ure screw out (counterclockwise) to a av lue leaner than specification. Then, tru n the mi-x tru e screw in (clockwise) to bring the CO av lue into specification. Always adjust from the lean side hw en setting CO.