Sganderson
Registered Member
I also got someone to hook their obd1 scanner to it and was unable to get anything
CK5
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Rough idle when cold
- Thread starter Sganderson
- Start date
As in would not connect to vehicle or no codes? Should at least get a code 12 twice for no problem found.
Check all your fuses, some vehicles use the same power source as the cig lighter and the power for the code reader. Not sure if thats on the OBD1 OR 2 tho.
I had a 92 S10 that did that rough idle on initial start and would go away in less than a minute. Never fixed it before getting rid of the vehicle.
I think i remember reading later on about a harness on the engine causing the problem, possible to the distributer but not sure, been quite a few years. Could research into that.
Just a thought.
Check all your fuses, some vehicles use the same power source as the cig lighter and the power for the code reader. Not sure if thats on the OBD1 OR 2 tho.
I had a 92 S10 that did that rough idle on initial start and would go away in less than a minute. Never fixed it before getting rid of the vehicle.
I think i remember reading later on about a harness on the engine causing the problem, possible to the distributer but not sure, been quite a few years. Could research into that.
Just a thought.
You could try re-seating the PROM, you need to figure out why no codes. As mentioned, you HAVE to get a code 12, or something is wrong in that circuit, which could affect everything else. ECM, PROM, and/or any of the wiring to the ECM.
Not bad to have a spare ECM/PROM around to swap for troubleshooting, easier than doing all the wiring checks, but not worth spending good money on.
Not bad to have a spare ECM/PROM around to swap for troubleshooting, easier than doing all the wiring checks, but not worth spending good money on.
AlaskanDad
Registered Member
Have you tried a new fuel filter? That was part of my problem.
Embarrassing story: Last week on the way to class it stalled out six times. I HAD to be at this class because it was review for my test this coming week. My wife was dropping out son off at school and was unavailable to come back and take me in.
Was unable to get it back home and was stranded next to an auto-shop. I always do my own work, but it was -10 out and wind was picking up. So I swallowed my price and had him replace my fuel filter. That filter was trashed! Water was in my fuel because temperatures were up and down and the filter was clogged like no other. -All the fuel that was coming out was very brown.
Turns out my fuel pump trainer was also missing, it rotted off.
Had the shop owner replace the fuel pump and make sure the truck was in time on top of the filter. Also, was out of gas
-Because it was so dang cold out my fuel gauge was hung up. I thought there was at-least 12 gallons left.
Anyways, this fixed my problem. I am going to replace the O2 sensor since my check engine is going on and off since it got out of the shop. Will also replace IAC, injector, and Map sensor on Tuesday.
Hopefully you will get a kick out of my little miss hap. The shop owner cut me a major break in price. he even installed my exhaust and fixed my driver power window with out charging, plus he knocked 20% off over all bill for being a college student.
Good luck!
Embarrassing story: Last week on the way to class it stalled out six times. I HAD to be at this class because it was review for my test this coming week. My wife was dropping out son off at school and was unavailable to come back and take me in.
Was unable to get it back home and was stranded next to an auto-shop. I always do my own work, but it was -10 out and wind was picking up. So I swallowed my price and had him replace my fuel filter. That filter was trashed! Water was in my fuel because temperatures were up and down and the filter was clogged like no other. -All the fuel that was coming out was very brown.
Turns out my fuel pump trainer was also missing, it rotted off.
Had the shop owner replace the fuel pump and make sure the truck was in time on top of the filter. Also, was out of gas
-Because it was so dang cold out my fuel gauge was hung up. I thought there was at-least 12 gallons left.Anyways, this fixed my problem. I am going to replace the O2 sensor since my check engine is going on and off since it got out of the shop. Will also replace IAC, injector, and Map sensor on Tuesday.
Hopefully you will get a kick out of my little miss hap. The shop owner cut me a major break in price. he even installed my exhaust and fixed my driver power window with out charging, plus he knocked 20% off over all bill for being a college student.
Good luck!
When I was troubleshooting my issues a while back, this came up as a possibility all the time. Leaks in the exhaust system can fool the O2 and make you run rich. The idea is that leaks can seal up when everything gets hot. In your case, it depends what you mean by "warmed up" though. Since the ECM doesn't even use the O2 for the first few minutes, if it runs rough right away and goes away fairly quickly, it's probably not this. If the tune is off or you have some other kind of issue, things may abruptly get better when the system goes closed loop... but you did mention gas smell, which is consistent with an exhaust leak I think. If you have a way to monitor the ALDL you could see if they symptoms get better or worse when the system goes closed loop.
Does it run rough immediately on start, or does it get worse before it gets better?
My 85 carbed 305 does the same thing. Always has. Not sure why.
