alright guys... i need some help with the 96 convertible i bought recently. it's a 2.4, 5spd. Mods are ebay intake and a pacesetter header with a 2.25" exhaust. bought the car with a slight hesitation problem. two days ago, the hesitation problem worsened alot and now the car does not start. it does crank and occasionally it'll run really rough for a few seconds and then die. the fuel pump does cycle (is there a way to check fuel pressure on the ld9? i know the eco has a purge valve in the fuel line) like it should. i've checked all the fuses.
replaced so far:
map sensor (new, based on code car was throwing)
egr valve (new, based on code car was throwing)
crank position sensor (new, based on code car was throwing)
spark plugs
coil pack (with a junkyard piece)
planning on changing the fuel filter in the next day or two as i'm not sure when it was changed last.
off the top of my head i can think of probably a dozen things that COULD be causing part or all of the problem (ecu, icm, coil packs, o2 sensor, fuel injectors, fuel pump, faulty wiring, etc)
I searched and have a few ideas but i'm trying to find out if anybody have an experience with a similar situation or any ideas on this one...
wish i could help....but diagnosing is my weak spot.
what codes, if any, are being thrown? if you could borrow a scanner from someone or rent one from autozone (they refund the full price when you bring it back, i think) maybe you could get it to turn over and see what the scan tool says.
good luck man. this is the frustrating part, i know.
95+ Cavalier and Sunfire Convertible Service Manual! A must read for vert owners!
i'm using hptuners to pull the codes...
car was throwing an egr pintle position code (replaced the egr), a map code (replaced the map sensor), and a crank position code (replaced the crank pos. sensor)
also have a system bank lean code and a misfire code... i need to scan again as the car started for a few seconds after we put the egr on, ran really rough, and then shut off. need to see if the car threw any more codes.
fuel filter will be replaced either tonight or tomorrow night.
if i can't figure it out by the end of the week, it's going to a garage to have a diagnostics run... i refuse to keep throwing money at the car for no reason...
When you pull the filter find out if the fuel pump is working.
I would check the plastic housing under the 2.4 cover. I think it is called the IDI cover. And the part I believe is called the ignition control housing. Can't remember, since it has been a while. But it is the plastic piece under the 2.4 cover. If it has any cracks in it no mater how small and miniscule you think it may be it needs to be replaced and that will most likely be your problem if it is not a fuel filter problem. It is I think a 12 to 20 dollar piece from the parts store. DO not use a junkyard one since it is most likely in the same shape.
fuel filter didn't fix the problem and the fuel pump is working properly.
took the two ignitions i have to autozone and had them tested. icm checked out ok. we also found a dead coil pack and one of the housings had a dead pin... not sure if the bad pack AND the housing were together though. going back after dinner to put the ignition back in to see how we make out.
please god let this work.
if that doesn't work try cleaning iacv(idle air control valve) becarful not to break about 70-80 dollar part. usually these cause a rough idle. other posibility is bad ecm, to check you have to have a scan tool to show live feeds. if you don't might want to find yourself an experenced diag tech.
ok... ignition is back in and still nothing... check the iac valve, cleaned it, and put it back in. still nothing. scanned the codes, saw a cam pos. sensor code, replaced it with a junkyard unit that we had in the car when it was still running (originally bought it to try and remedy the hesitation problem) and STILL nothing.
when i scan the ecu, hptuners will pull the trouble codes but will not read the rest of the ecm. not sure if my ecu revision is just not supported by hptuners yet or if there is possibly a bad/faulty connection... i'm going to check the ecu connections tomorrow for corrosion or a loose connection. if i don't find anything, pretty sure the car is going to a garage with a diagnostics machine...
? does it fire or sputter if you spray starter fluid or carb cleaner in it? thats a good way to check to see if it is ignition or fuel.
I know it'sa shot in the dark but just recently I had extremely similar symptoms ..
My car started with a sort og bogging down when I tried to accelerate .. then it got to the point where the car would run really rough for a few seconds then die .. and to the point the car would just turn over and not start at all .. checked spark plugs .. coil packs , ignition module and even fuel pump and filter
turns out my problem was a clogged catalytic converter .. just give it a shot .. loosen the bolts at your header flange and try to start it ..
another thing could be your PCM itself, since it seems to keep throwing codes at you that don't help.
don't really want to replace the motor. it's only got 78k on it and recently had water pump, head gasket, and timing gear replaced (by the previous owner)
bryan... i'll give that a shot and see if it helps any.
damn... forgot to check if spraying carb cleaner would work...
it's not the cat. checked the connections on the ecm... nothing wrong with them although i'm not ruling out the computer itself. it seems the mount it bolts up to is not bolted to the car so it would have been experiencing alot of vibration from the mount moving around and such.
anybody know of a way to test the pcm? autozone can't test it....
after you try the carb cleaner try setting your idi cover with all the boots and plugs on top of the cam towers and see if there is spark. might be the boots or plugs. try them off your donor motor you mentioned if nothing and your set on the ecm try a local yard for one looked like only around 20 bucks. besides the way i told you before thats the only way i know how to test an ecm. gl
i don't have a junkyard motor... just happened to have a spare ignition setup (coil packs and housing) lying around.
i'm going to try to get a tow dolly and get the car over to my parent's garage this weekend where hopefully i can continue the diagnosis.
Sounds to me either bad coils and or housing or a bad pcm, all recently stated before. Are you sure the ignition components you are substituting are good? I had all sorts of problems trying to start and drive my cavy once when i had a small crack in the IDI housing which eventually grounded out the coils. And like 4 bangerdeathsquad said, could be the pcm. All sorts of codes like that either mean you have a bad pcm, or you bought a polished turd with all sorts of problems!!
Personally I have never used HPT and don't know too much about it but I would try to get the codes read with a Tech II scanner and go from there. With a Tech II you can watch the motors sensors and see if your pcm's reading them correctly. that right there could rule out the computer. Then watch your ignition voltage while cranking: showing coil status. Just some tips on how I would go at it. Good luck!!
had the coil packs, coil housing, and icm tested at autozone and they tested out ok (which i mentioned earlier)
at this point, the car will sit for a bit... cash is too low to troubleshoot...
I see you say you replaced the crank positions sensor. Now don't quote me but doesn't it have to go through a case relearn after something like that?
i'm going to compression test the car when i get it into the garage so i can hopefully rule out the timing being off...
ecu is the next purchase.
pretty sure the 2.4 doesn't have to do a case relearn when you replace the crank position sensor. (at least the haynes manual said nothing about it... nor did the gm service manual my buddy has)
took the egr back and ordered a new ecu... hopefully should have that in early next week. haven't gotten the chance to compression test the car yet but it is in the garage.
What about an oil sending unit. I cant recall if our cars are such that if Oil pressure gets too low the fuel pump shuts down the car from running. Probably an odd idea, but something that wasnt mentioned.
Check to see if the little rubber map sensor hose is cracked or dryed up.
It makes the car run like poopy.
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