850 10v starting and idling problem
#1
850 10v weird starting and idling problem
Hi all,
I have a 1995 manual 10v 850, about 100k miles with a peculiar problem. The car has issues starting after it has just been turned off, if I turn the key the starter will engage and the engine will fire, but often it will lose rpm and stutter a bit about the 300rpm mark before it dies. If I try starting it again straight away it often will not even fire. I generally have to wait about 5mins before I can get it started again on a mild day. On warm days the problem is exacerbated. I have also had it stutter and die when slowing down, I dip the clutch at about 1500rpm and it will just cut out after it has coughed a few times. Again I have to wait about 5 mins depending on how warm it is outside before I can get it started again. It also won't start if the air temperature is above about 85F. Apart from this it runs fine!
My suspicions thus far have been the MAF (which it turns out the 10v doesn't have I'm fairly sure), crank angle sensor, MAP, idle control valve, idle stepper motor or maybe even something to do with the thermo fan? I don't know where to start really. I have taken the car to a few mechanics who just shake their heads as there are no error codes coming up.
I also had a go at setting the air temp sensor thermostat in the bottom of the airbox to permanent cold air, which has improved the performance a little but hasn't fixed the problem.
Any ideas?
Cheers,
Pat
I have a 1995 manual 10v 850, about 100k miles with a peculiar problem. The car has issues starting after it has just been turned off, if I turn the key the starter will engage and the engine will fire, but often it will lose rpm and stutter a bit about the 300rpm mark before it dies. If I try starting it again straight away it often will not even fire. I generally have to wait about 5mins before I can get it started again on a mild day. On warm days the problem is exacerbated. I have also had it stutter and die when slowing down, I dip the clutch at about 1500rpm and it will just cut out after it has coughed a few times. Again I have to wait about 5 mins depending on how warm it is outside before I can get it started again. It also won't start if the air temperature is above about 85F. Apart from this it runs fine!
My suspicions thus far have been the MAF (which it turns out the 10v doesn't have I'm fairly sure), crank angle sensor, MAP, idle control valve, idle stepper motor or maybe even something to do with the thermo fan? I don't know where to start really. I have taken the car to a few mechanics who just shake their heads as there are no error codes coming up.
I also had a go at setting the air temp sensor thermostat in the bottom of the airbox to permanent cold air, which has improved the performance a little but hasn't fixed the problem.
Any ideas?
Cheers,
Pat
Last edited by phunter92; 10-27-2011 at 02:14 AM.
#3
Do you have a check engine light on?
#4
#5
From cruising posts here I haven't seen anything that would make me think the CTS fails any more often than any of the other items you are suspicious of. The CTS is just another part in the system. The thing about the temp sensor is that if it's reading 30 degrees colder than the engine it will flood the engine and if it's reading 30 degrees higher it will lean it out. In both cases it might not set a check engine light because it might still be in the operating range of what the computer thinks is acceptable but the engine will run like crap. Thus, no check engine light but a component causing a problem and is going bad just not bad enough yet to trip the light.
Last edited by Kiss4aFrog; 10-29-2011 at 03:35 AM.
#7
Well I managed to fix the problem. Correct in thinking it was fuel related, ended up being that pesky fuel pump relay. I had partially dismissed this problem earlier as i was under the impression that the faulty relays fitted at the factory were green in colour wheras the one in my car was pink. Turns out the pink ones can fail as well. Interestingly the replacement is made in Hungary.
Thanks for your input everyone
Thanks for your input everyone
Thread
Thread Starter
Forum
Replies
Last Post