Rabbi Posted March 20, 2008 Report Share Posted March 20, 2008 picked up a 1992 z34 today for $400. The guy says the car has a problem staying running, The car will start up then just die after a few seconds of running. It will not start up at all now. The timing is not off for sure, Its turning over fine. It just wont fire up. Where should i start? Sounds like a fuel/electrical problem. What should we start with? Havent pulled the code's yet, Will be doing that on sunday. Quote Link to comment Share on other sites More sharing options...
slick Posted March 21, 2008 Report Share Posted March 21, 2008 Check fuel pressure at the rail. Should be between 40-45. Check spark. Can easily be done by pulling a plug wire, sticking a screwdriver in the plug, resting it against the the radiator support, and watch for spark as someone cranks over the engine. Quote Link to comment Share on other sites More sharing options...
Rabbi Posted March 21, 2008 Author Report Share Posted March 21, 2008 also the previous owner put some crappy ass ebay intake on it. What sensors are supposed to be on the intake box & intake pipe? Theres only one on there as of right now, And its not even hooked up its just sort of sitting there....Maybe this has something to do with it? Its been a VERY long time since i had a 3.4 so im back to being clueless, About all i remember about this engine is the good old timing belt swap procedure heh. Going to be going to the junkyard in a few days, Going to pickup a ICM and a few other sensors. Quote Link to comment Share on other sites More sharing options...
Rabbi Posted March 26, 2008 Author Report Share Posted March 26, 2008 ok i tested for both fuel & spark. I tested for fuel at the fuel rail's valve thingbob (looks like a bycicle air valve) fuel sprayed out pretty good, So i guess its getting fuel. I Pulled two plugs out and both are getting spark. There is no service engine soon light on, So i guess its not throwing a code. Checked the timing belt and it looks like its in very good shape, Probobly has about 15 - 20K + miles on it from the condition it looks like its in. Now its getting both fuel and spark, What should i be checking next? I will run the codes tommarow hopefully if i can get back out to the car. ALSO! the engine looks like it may be from a newer vehicle, The top mount to pull the engine is scraped up so im assuming the engine has been pulled, or possibly the existing motor is from a newer car. Is there anyway to check to see what motor the car has come from? The engine is in REALLY good shape, It is probobly the cleaning engine bay i have seen that isnt a brand new vehicle. Im assuming the engine is from a newer Monte Carlo maybe. The engine also looks a little different from my 1991 lumina z34 that i used to own. I Dont remember the fuel injector cover on my old car saying "Duel Twin Cam V6" , Although it has been a good 4 years since i owned my old z34. Guys im stuck at a stand still here, What should i be looking for next? If its getting spark and fuel, It should be starting correct? Quote Link to comment Share on other sites More sharing options...
Rabbi Posted March 26, 2008 Author Report Share Posted March 26, 2008 another update, I Pulled the fuel injector cover and on the 3rd visible injector harness the wires seemed melted. Possibly the are being shorted out. Would one fuel injector not operating because of a short, Would the entire fuel injector system stop operating? Thanks Quote Link to comment Share on other sites More sharing options...
ismellrealbad Posted March 26, 2008 Report Share Posted March 26, 2008 Well it would def cause something not good. Fix it and go from there. Quote Link to comment Share on other sites More sharing options...
Rabbi Posted March 26, 2008 Author Report Share Posted March 26, 2008 the injector wires melted? Yea i will be fixxing that tommarow. Im really hoping the wires are shorting together and that would cause the entire injector circuity to fail =D that would really make my day, But i have a feeling there is more to the problem. ive seen a car start with only one injector working. So id assume that the injector being shorted wouldnt cause the car to not start. Quote Link to comment Share on other sites More sharing options...
Z34-5speed Posted March 26, 2008 Report Share Posted March 26, 2008 Stupid question but how are you sure that the timing isn't 180* off (if that's even possible on this motor{had a friend with a 240 had similar symptoms, fuel & spark, 180* off timing was his problem}). Quote Link to comment Share on other sites More sharing options...
Rabbi Posted March 26, 2008 Author Report Share Posted March 26, 2008 i pulled both valve covers, the cam marks line up properly with the crank mark. Ive done the 3.4 timing job about 8 times unfortunately lol, The timing is dead on. Quote Link to comment Share on other sites More sharing options...
Rabbi Posted March 28, 2008 Author Report Share Posted March 28, 2008 Update : injector wire was not melted, Just covered in electrical tape. Thats fine. Tested for fuel and its getting fuel to the rail. First two plugs are NOT getting spark on the front bank. its throwing no codes. ICM or Coilpack? Quote Link to comment Share on other sites More sharing options...
1990lumina Posted March 28, 2008 Report Share Posted March 28, 2008 But the third plug on the front of the motor is getting spark? I'm going to guess two coils are dead, but don't rule the ICM out either Quote Link to comment Share on other sites More sharing options...
Rabbi Posted March 28, 2008 Author Report Share Posted March 28, 2008 no we only pulled two plugs out to see if they were getting spark, Neather were. The car turns over and just wont start. We tested for fuel and its getting fuel at the rail. Just no spark on the only 2 plugs we tested. Quote Link to comment Share on other sites More sharing options...
88red4cyl Posted March 28, 2008 Report Share Posted March 28, 2008 I would definetely test the rest of them.. I'd say that the ICM would be a pretty good culprit.. At the very least a bad coil.. Quote Link to comment Share on other sites More sharing options...
Rabbi Posted March 28, 2008 Author Report Share Posted March 28, 2008 will test the other 4 plugs for spark tommarow Quote Link to comment Share on other sites More sharing options...
Rabbi Posted April 1, 2008 Author Report Share Posted April 1, 2008 Update : No spark on any plugs. picked up a used ICM / Coilpack today. Will be throwing it on. Hopefully it fix's my problem. If its not the coils/ ICM what would be the next item to check? Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted April 1, 2008 Report Share Posted April 1, 2008 Crank sensor. Quote Link to comment Share on other sites More sharing options...
Rabbi Posted April 3, 2008 Author Report Share Posted April 3, 2008 update : Tried a junkyard coilpack from a running vehicle, Still no spark. Will be trying a brand new crank position sensor tommarow. Gonna rent a compression tester as well. will report my compression #'s tommarow also, does anyone know the wire routing for the ignition system? gonna try to trace my wires and make sure i have no break in the wires. Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted April 3, 2008 Report Share Posted April 3, 2008 The harness wires or the spark plug wires? Quote Link to comment Share on other sites More sharing options...
Rabbi Posted April 3, 2008 Author Report Share Posted April 3, 2008 the harness, If i replace the CPS and i still have no spark im assuming that i have a break somewhere in my wiring. somebody posted that the Coilpack has a single wire ground wire on it, I replaced the coilpack and all i had was 3 harness connectors to plug into it. No "single wire" ground wire ANYWHERE to be seen. Maybe this is my problem? Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted April 3, 2008 Report Share Posted April 3, 2008 the harness, If i replace the CPS and i still have no spark im assuming that i have a break somewhere in my wiring. somebody posted that the Coilpack has a single wire ground wire on it, I replaced the coilpack and all i had was 3 harness connectors to plug into it. No "single wire" ground wire ANYWHERE to be seen. Maybe this is my problem? First, did you get the ICM tested? I would take whatever one is in the car, or that you'll be putting into the car and get it tested. For the coils you can test resistance at the towers which is secondary resistance, and you can test them where they plug into the ICM which is primary resistance. There are grounds on the transmission bell housing for the ICM and other parts of the car. There are two ground points on two bell housing bolts. Check those and make sure they are clean. If you're not getting spark on any cylinders my guess is crank sensor. Wiring runs from the crank sensor, along the oil pan/crank pulley area to the ICM. Wires from there run into the main harness and then to the PCM and to engine grounds. I can look in my service manual more indepth for you if you want. Quote Link to comment Share on other sites More sharing options...
88red4cyl Posted April 3, 2008 Report Share Posted April 3, 2008 the harness, If i replace the CPS and i still have no spark im assuming that i have a break somewhere in my wiring. somebody posted that the Coilpack has a single wire ground wire on it, I replaced the coilpack and all i had was 3 harness connectors to plug into it. No "single wire" ground wire ANYWHERE to be seen. Maybe this is my problem? First, did you get the ICM tested? I would take whatever one is in the car, or that you'll be putting into the car and get it tested. x2 You can put brand new coils on there all day long, but if the ICM is bad you still won't get spark.. Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted April 4, 2008 Report Share Posted April 4, 2008 Well it can run, but not great. Quote Link to comment Share on other sites More sharing options...
Pontiac6KSTEAWD Posted April 4, 2008 Report Share Posted April 4, 2008 Crank position sensor, or, injectors. 1 bad injector, takes out the whole bank. Quote Link to comment Share on other sites More sharing options...
Rabbi Posted April 4, 2008 Author Report Share Posted April 4, 2008 Crank position sensor, or, injectors. 1 bad injector, takes out the whole bank. im getting fuel. im not getting spark. I Changed the ICM with the coilpack. Quote Link to comment Share on other sites More sharing options...
Rabbi Posted April 4, 2008 Author Report Share Posted April 4, 2008 First, did you get the ICM tested? I would take whatever one is in the car, or that you'll be putting into the car and get it tested. yea, the icm/coils were from a running junkyard vehicle. (owner is a personal friend of mine, i trust his word) There are grounds on the transmission bell housing for the ICM and other parts of the car. There are two ground points on two bell housing bolts. Check those and make sure they are clean. I Didnt have any ground wires on my ICM. I Had 3 plugs and thats it. Maybe im missing a couple wires or something?? Quote Link to comment Share on other sites More sharing options...
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