My 3.4 Won't Run!!!

[Sonyman]

Ha! Ha! Yeah i've accepted it but it is worth it. If that is what it takes to get it back rollin', then so be it! My and homie just found a 96' Cutlass with a 3.4 in a salvage yard and pulled the engine and tranny over the weekend. I gold mind find between the both of us. Also i scooped up like you stated some injects, tps and map. I also got some wiring to do so my week and weekend coming is going to be full. But it's a automatic trans.

[dohcfiend]

how much was the ecm? geez man, you are going to have enough parts to completely build a new engine before long.

do you have an aldl scanner?

do you have a digital multimeter?

you can probably buy one or both of them with all the money you have in these parts after you return them.

go to the jy and get yourself some injectors, a tps, a map and let me know after you crank it up.

is this gp a 5spd? if so i may make you an offer on it. cars from texas rule. nice and dry .

[Sonyman]

i bought a new ECM, using the same chip of course, no change.

[series8217]

This sounds exactly like what happened when my old '88 2.5 Iron Duke ECM took a dump. It had a cracked trace on the board, but if things were bent just right it would start and run. Really crazy fuel injector behavior, etc. It was all messed up and totally unpredictable. I ended up figuring it out because I had the ECM case apart, and tried running the car.. it started! I pushed on the case and it sputtered and stalled. I repeated this numerous times to be sure the test was valid.. replaced the ECM and all was well. I'm not saying you should go out and buy a new ECM right away, since they're pretty expensive, but if you have a spare one or some other ways to test this one, that may be a good idea!

[grandprixgtp_91]

yes gm parts are alot higher of quality, you can even feel the difference in weight and material, trust me they just work, and alot better.

Jake

[dohcfiend]

i hope you kept all the receipts so you can return everything once you find the problem. .

i am telling you, bite the bullet and buy a digital multi-meter with the money from all your returns. eventually it will pay for itself. sooner than later if youhave older cars like me .

depends on the part.

you can save a few bux and go with cheap coilpacks, they will not last as long. same can be said for sensors up top that are easy to replace and do not operate off of tight tolerances.

as far as a CPS goes, ya gm. starters, definately gm, if you get nothing else gm get yourself a gm alternator for this car!!!! TRUST ME.

[Sonyman]

ok GP '91, so in your experience, there's a higher quality in "GM" parts than let's say auto zone, oreily type parts?

[Sonyman]

it was replaced a year ago brand new

[grandprixgtp_91]

dont waste your money on aftermarket junk sensors, we see enough problems with them at work, spend the little extra and go gm.

Jake

[grandprixgtp_91]

hard to say, could be a bad wire, you might need a junkyard engine harness,

did you replace the crank sensor before or after all your problem?

Jake

[Sonyman]

i'm gonna get a new tps and MAP this weekend for sure. So what its going to end up is all sensors on the engine will be new. therefore if the engine still doesnt work, then it must be the communication links (wiring).

[Sonyman]

gotcha but lets assume the sensor is ok, then what? As long as i have deal with this car, i should have a few gray hairs in my head by now but i feel i'm almost there of finding the little bastard thats causing this big 3.4 from working! Damn near 80%of everything is new, there's not really not much else to diagnoise i feel unless something has lied while it was tested made me to look elsewhere. In short i feel its a simple engine problem inspite of the BIG problem its causing me.

[dohcfiend]

yes, but ive seen crank sensors mess up when they warm up.

Jake

x2

sometimes they crack and when it is cold, it runs fine but when it heats up the crack expands allowing abnormal operation.

the only real way to check one is with an o-scope. hell i am a lvl 2 electronics tech and i do not even have one. they are high as hell and my boss is cheap.

when you crank, you should see uniform sign waves but if the waves spike like mountain peaks, the part is bad(not that it matters).

anyway, you need a meter to check the TPS and MAP or just replace them and hope, your call. TPS is cheap $20 for an advanced auto one, i do not believe the MAP is so cheap. JY is free if you have the pockets and the ballz.

[grandprixgtp_91]

no, im saying check for spark when the car dies out when it warms and if you loose spark then maybe buy a gm one if the connectors are good.

Jake

[Sonyman]

so you suggest i buy a "GM" crank sensor part?