ok i have been trying to figure out why my car is surging on cold start up barely does it if it is warm outside. only surges for a minute then i believe the computer is going to limp mode. the other thing i noticed is if i try to pull out and drive it right when i cold start it. it has a stumble or sputtering to it just for like the first 30sec of driving. after that or if i let it sit and idle just for a minute the car drives fine minus probably running a little rich i would assume from what ever the heck is going on.
still problems surging idle on cold start
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I have the basic bolt ons. cai edlebrock performer intake, 70mm t.b. fox swap. full exhaust with shorty headers underdrive pulleys. egr is completly deleted. when i checked codes it was throwing one for the thermactor which i believe is just the pollution pump being removed. it also threw a code for the egr but i think that should be fixed because i installed that little plug in bypass solenoid to trick the computer and reset code but i haven't resacnned to make sure that specific code is not coming up. then the last code was a 10. said something about low ballance in number one cylinder but that was a stored code it said not present. there are also no chips on car or tunes i am aware of
I would recheck codes to be sure of what is present. I would retrieve KOEO, memory and KOER codes.
It sounds like the ten you saw was a separator code. You need to blip the throttle to enter cylinder-balance testing.
It sounds like the ten you saw was a separator code. You need to blip the throttle to enter cylinder-balance testing.
To check the ECT, have the engine at 50*F. Turn the key on and note the voltage (one wire will show 5V and the other will have less voltage than that. You want the latter wire). The one with less voltage is variable and will change inversely with respect to increases in engine temperature. Note the meter reading.
You can also try doing this before getting the engine up to 50*F and we can interpolate the results. It's just that a reading below 50* is not very accurate.
You can also try doing this before getting the engine up to 50*F and we can interpolate the results. It's just that a reading below 50* is not very accurate.
The sensor can be out of calibration - it can be within absolute spec but not read correctly for the conditions. It's not likely to be the issue but since it takes 30 seconds to check, it can be worth doing.
From personal experience excessive cold start enrichment will cause the idle to surge (oscillate) when first starting. Since the enrichment is commanded by the PCM from a look-up table and you can't change it without a chip that would lead me to think that a sensor is giving the PCM some bad data. We've eliminated the ECT sensor so that doesn't leave to many others. The first one that comes to mind is the O2 but I'm not certain that they are switched on until the engine warms. Perhaps someone can confirm that. The other thing that I don't understand is the 2 digit code 10. All OBD1 systems are 3 digits starting at 111 - 998. I think you should retest and confirm there are no codes. You can buy a reader for about $30.
Save on Equus 3145 at ToolTopia.com
Save on Equus 3145 at ToolTopia.com
The O2's are not utilized till they light off (about 600*F), which can take 30-120 seconds.
I would need to look it up but code 10 might still be used on the three digit cars (since it's not a code but a prompt to do a WOT goose for the CBT).
I would need to look it up but code 10 might still be used on the three digit cars (since it's not a code but a prompt to do a WOT goose for the CBT).
my buddy has the scanner so i will rerun the test. at this point i think I might back track through everything to make sure something it not being over looked. this one is a real hair puller one of the harder problems i have had to deal with. had idle issues before but always been able to figure it out. thanks for the help. i will keep you posted but feel free to post if another ideas comes up
alright i am convinced i have a vacuum leak. when i am coming to a stop the car idles down to about 1000rpm with clutch pushed in. then when i stop it idles down to normal about 800rpm and does a quick little jump to about 1,100 and goes right back to normal. does this about every time i come to a stop. and I also hear a little whistle sound when i am under the hood
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