• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

cranks but no start...stumped

T

t79z28

New member
well I just bought a 97 grand prix gtp, previous owner said it dies randomly, no codes so the process begins. It either wont start at all or starts with the possibility of stalling whenever it feels like it, no stumbling and no loss of power
I checked for spark none, tested ICM and coil packs ICM was replaced...car started and later died and left me to push it home lol
Checked fuel pump, hear it prime and also depressed the valve it had fuel.
Crank position sensor was the next suspect, changed that bad boy out fired right up, did 4 test starts and then test drive. Threw code p0108 Made it threw 5-8 min test drive with no issues. I parked it for a few min came back to start it and nothing. Thats where she sits now, re checked for spark and fuel pressure still had both.

I read that sometimes the fuel pump resistor can cause this kind of an issue, I have one on order it should be here tomorrow, thats the next test im going to throw at it. Also going to try starter fluid into the T body if it starts then dies I believe that's a bad fuel pump?
Im really stumped I thought for sure the crank sensor would fix my issue, also it threw a code at me p0108 manifold absolute pressure, would that cause it to crank but not start? I did find a cracked vacuum line and replaced it and it still refused to turn on. It is a gtp supercharged with 166000 on the clock. for the few times it did run nothing struck as being bad, runs and shifts great, loving this car so far just wish it would stay on. Looking forward to what the future holds lol
 


ok, I tried the ideas and neither worked, but i did remember one of the coil pack bolts broke, so i rechecked it and pushed it back down, car fired right up. So I ziptied it down hope that holds. Now onto the code, how would I check the intake gasket for leaks? are there steps up to it or just jump in and start looking? Thanks for your guys help and fast responses
 
I had the map Code when I got mine. Vacuum leak somewhere. I replaced every single gasket.

The rest sounds like intake, pcv, or battery /grounds.

Possibly fuel filter.
 


lol it happens, and deff will check the hardware store. I love zipties but ill be dammed in Im already zipping a one day old car. As for the code it sounds like you pretty much had it rebuilt? Oh this is going to be fun. Just a thought can I have it smoke tested and hope I get lucky?
 
BOLT,IGN COIL(DELCO-REMY)(HEX WA HD,M4.5X.75X34.5, 28 THD,10.6 OD,GM 6171,GM 1345,TAP)(02.383)(ACDelco #10470758). BOLT-SEAL-STUD, Ignition Coil Mounting. For: H 3.8-1(L67) (1992-1995) (1992 - 1999). Required: 06
 
I see gm does not list zip ties are a option lol ok well my hopes of having it hot to trot by the weekend is shot, thanks for your help, im going to start with the easy ones and keep digging untill the engine ends up all new, Ill keep you posted
 
Check the backside of your UIM. There's a vacuum booster tube back there that can go bad. O-ring. Whatnot.

Or your pcv valve may just need to be replaced.

Would a clogged egr set off this code?

Use maf or electronic cleaner on your maf sensor and air temperature sensor (intake).
 


well I looked behind the engine by the fire wall and the fuel vapor purge valve had 2 vacum hoses on the side and theres a nipple on the bottom but no vaccum line. Is there supposed to be one? If so where does it go? The car starts up runs and drives just fine but its dead in the water unless I can fix the dumb code. The purge valve is right next to a delco remy 42871 (I cant find what it is) and it also has an exposed nipple just wondering if they connect?
 
I have now lol this is more of a project car then I anticipated Ill post back w what I find, thanks for that site
 


might have it, i pulled off the map sensor and the prongs broke right out, so i deff need to fix the plug, can i just splice a new connector onto the existing wires or is it more complicated than that?
 
ya the prongs stayed on the harness but the plastic part and the rubber gasket came off w the sensor. The prongs are fully exposed, well off for a replacement plug. When I drove it out of the way to get to my other car it acted the same as it has been the whole time so im thinking this is my code
 
Could be, since it says MAP Pressure Circuit High Input, meaning a low vacuum reading(or none)


Potential causes of a P0108 code:

Bad MAP sensor
Leak in vacuum supply line to MAP sensor
Engine vacuum leak Short on signal wire to PCM
Short on reference voltage wire from PCM
Open in ground circuit to MAP
Worn engine causing low vacuum

P0108 - MAP Pressure Circuit High Input

Read more at: http://www.obd-codes.com/p0108
Copyright © OBD-Codes.com
 
You must log in or register to reply here.
Back
Top