94 formula runs good until it warms up
#1
94 formula runs good until it warms up
Then it starts running pretty rough kinda like its missing n stuff. seems to smooth out when I give it wot. It threw an ses light up the other day but i think a mouse got into the wiring because no scanners seem to be able to communicate with the car. what do you guys think?
#2
Re: 94 formula runs good until it warms up
I had the same problem with my car after my header install. I found it to be the spark plug wires were arcing. I opened the hood at night with the car running at idle. You could see the plug wires arcing. If you have the factory exhaust manifolds and the factory routing of the plug wires it may be almost impossible to see. But its worth checking. How old are your plug wires?
I also would check for loose sparkplugs and check the plug wires before pointing the finger to the optispark.
I also would check for loose sparkplugs and check the plug wires before pointing the finger to the optispark.
Last edited by Matts97camaro; 09-10-2012 at 04:20 PM.
#4
Re: 94 formula runs good until it warms up
still have factory manifolds. why would that make a difference anyway? if the wires are bad they would be bad when the car is cold OR hot i would think
#5
Re: 94 formula runs good until it warms up
Plugwires can and will arc of the manifolds, its just harder to see because the factory runs the plugwires against the block and right under the manifolds.
To give you a example of my plugwire situation. My car ran great, no missing or surging the first 10-15 minutes. As soon as the car was at operating temp the missing and rough idle would start As the plugwires got warm the resistance of the wires was almost nothing, causing the spark to arc or jump to any metal object close to it. In my case the wires were so weak they were arcing almost 1/4 to 1/2". It was easy to see on the headers. As soon as I replaced the wires with new
8mm siicone wires problem solved. Several people thought it was the opti.
To give you a example of my plugwire situation. My car ran great, no missing or surging the first 10-15 minutes. As soon as the car was at operating temp the missing and rough idle would start As the plugwires got warm the resistance of the wires was almost nothing, causing the spark to arc or jump to any metal object close to it. In my case the wires were so weak they were arcing almost 1/4 to 1/2". It was easy to see on the headers. As soon as I replaced the wires with new
8mm siicone wires problem solved. Several people thought it was the opti.
#6
Re: 94 formula runs good until it warms up
hmmm i have had the arcing problem cross my mind. ive seen some of my other cars do that before. maybe ill go look at it in the dark tonite. ill post what i see tonite.
#7
Re: 94 formula runs good until it warms up
Sorry been away from the computer a few days. I looked at my wires in the dark and couldn't find any at arcing anywhere. Anyone have any more ideas?
T
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#8
Re: 94 formula runs good until it warms up
Can you bypass the Delteq? They are not very reliable.
What did they try to read your codes with? Some of the newer OBD-II/OBD-I scanners are looking for a 12V pin in the ALDL connector, and we don't have on on the OBD-I LT1's.
Think about the things that can break down when they heat up - ICM (but you have the Delteq controller - also subject to heat soak), Opti cam position sensor, coil (but you have the Delteq's 4 Northstar waste spark coils), fuel injectors.
What did they try to read your codes with? Some of the newer OBD-II/OBD-I scanners are looking for a 12V pin in the ALDL connector, and we don't have on on the OBD-I LT1's.
Think about the things that can break down when they heat up - ICM (but you have the Delteq controller - also subject to heat soak), Opti cam position sensor, coil (but you have the Delteq's 4 Northstar waste spark coils), fuel injectors.
#11
Is it possible that you may have a plug wire that's burnt and melted to a part of one of the manifolds??
I had this same problem and looked for arcing and didn't see any, but upon closer inspection my #5 plug wire had touched and melted on my header tube..
I know your running manifolds but i'd throw it out there..
I had this same problem and looked for arcing and didn't see any, but upon closer inspection my #5 plug wire had touched and melted on my header tube..
I know your running manifolds but i'd throw it out there..
#13
Re: 94 formula runs good until it warms up
Well i just had the top end of the motor off and inspected all the wires and everything before putting them back on. And as a side note it did have this issue before i tore it down and put it back together. Yeah I actually didnt even look at the wires until it warmed up and started running bad, but couldnt see anything. I even had it up on a lift looking at it from below in the dark. Ive got some new ac delco o2 sensors i got off a member for cheap ima try when they get here. mab i should see if sombody here has a set of oem style plugwires theyd sell me cheap so i can bypass my delteq setup? Any more bright ideas are more than welcome and appreciated here. This is gettin frustrating.