QuestionQUESTION: I have a 1988 Toyota V6 P/U that all of a sudden quit firing on cylinders 2, 4 and 6. It is getting spark to the plugs and is in time. Seems as though it is not getting fuel on the left bank or those three injectors are not firing. What could cause this? Can the computer forget to fire the injectors?
ANSWER: Disconnect one of the injector connectors on that side, you should be able to get to #2, disconnect the connector and connect a test light across the terminals and see if the light flashes when the engine is cranking over, let me know. Was anything else done to the engine recently?
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QUESTION: I did the lamp test and did get voltage at all three injector connectors. The lamp did not light up much but did glow red (low voltage). Funny thing, the "check engine light" has not come on and when I check the diagnostic codes I get code 51 which has something to do with the air conditioner switch. You would think I would be getting codes if the engine is missing on three cylinders. Thanks for your help.
ANSWER: Did the test light flash when connected to the two terminals of the connector? Compare to the other side, what is the difference?
All injector connectors will have voltage to one side, the other side grounds through the computer in an on/off pattern to turn the injectors on/off with the engine cranking or running.
Ignore the 51 code,irrelevant.This engine uses the OBD I diagnostic system which doesn't have the ability to dtect mifires.
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QUESTION: Tested all three injector leads (2,4 and 6). All three will only turn the bulb element red, but no flashing. I can't compare this to injectors number 1,3 and 5 as there is no access. When I put a listening stick to injectors 4 and 6 I hear a definite clicking sound even though these cylinders are missing. Injector # 2 does not click but when I unplug the injector lead the engine speeds up then slows down when I connect it again. When I first started looking at the wiring I noticed the insulation had hardened and cracked off the # 2 leads and the positive and ground may have actually been touching. I have separated them now but if they touched would this have messed up the computer.
Other things tested: Valve timing is correct. Ignition timing is correct. Compression tested okay. Gas pressure is okay on the fuel rail. Wires test okay and new spark plugs were installed. I am totally puzzled!!
AnswerThose wires touching would have blown a fuse. Check the ground connections at the rear of the pass side cylinder head on top of the camshaft housing. If those or ok you should start checking continuity between the injectors and the ecm connectors, only if the wiring has an open circuit or short to ground should the ecm be replaced.
