Hey all,
So this is a part two to this thread:
https://www.stangnet.com/mustang-forums/threads/1991-5-0-fires-up-every-time-idles-perfectly-but-once-it’s-warm-it-won’t-idle-for-more-than-15-seconds.921537/
I ended up taking the car to the shop. It had a bad TFI, computer was wired incorrectly, they had to hook up the car to a "breaker box" (not even sure what that is) to diagnose it and it took them a while to figure it out. There were some other issues as well (can't remember off the top of my head) that they sorted through as well. Also had the rear end rebuilt (previous owner lied about that, clutch packs were toast and the driver's side axle had signs of galling). They said that when they had the car on the lift, they could spin one rear wheel freely and the other wouldn't do anything. Finally, They replaced the leaking valve covers and some front suspension pieces that were bent/loose.
So anyway, they got the car running, and it was running and driving great, except that the shop mentioned to me when I picked it up that it would pop and backfire badly out of the exhaust when it was cold, but ran fine otherwise. They said to drive it for a little bit and if the car didn't stop having that issue, to bring it back to them because it likely needed a tune.
So, the problem persisted, and I brought the car back to them for a full dyno tune. They put an SCT chip on it and did two hours of dyno tuning. Baseline run was 261, they ended up squeezing 285 out of it by the end (on a Dynojet).
So now the car runs even better. Idles perfectly, runs smoothly, etc.
EXCEPT: It still doesn't run great when it's cold, and backfires/pops out the exhaust and has significant hesitation until it warms up. Once it's warm, it runs HARD, pulls smoothly throughout the RPM range, etc.
I feel like this is an issue they should have resolved. The car shouldn't be popping and sputtering when it's cold like this.
I did some quick looking on the forums and people said they had this issue and it was either the ECT, ACT, or the BAP, or dirty injectors that needed cleaning
The car does not have a check engine light on. I am getting intermittent "low coolant" lights on the dash (it's illuminated about 75% of the time), despite the coolant level being adequate. Also checked the coolant system for leaks via pressurizing the radiator, and it seems file. The car does not have an EGR or any other emissions equipment.
This is clearly an issue with a sensor or something when the car is in open loop before it warms up. The car runs quite well when it's warm, and pulls hard.
What do you guys think?
So this is a part two to this thread:
https://www.stangnet.com/mustang-forums/threads/1991-5-0-fires-up-every-time-idles-perfectly-but-once-it’s-warm-it-won’t-idle-for-more-than-15-seconds.921537/
I ended up taking the car to the shop. It had a bad TFI, computer was wired incorrectly, they had to hook up the car to a "breaker box" (not even sure what that is) to diagnose it and it took them a while to figure it out. There were some other issues as well (can't remember off the top of my head) that they sorted through as well. Also had the rear end rebuilt (previous owner lied about that, clutch packs were toast and the driver's side axle had signs of galling). They said that when they had the car on the lift, they could spin one rear wheel freely and the other wouldn't do anything. Finally, They replaced the leaking valve covers and some front suspension pieces that were bent/loose.
So anyway, they got the car running, and it was running and driving great, except that the shop mentioned to me when I picked it up that it would pop and backfire badly out of the exhaust when it was cold, but ran fine otherwise. They said to drive it for a little bit and if the car didn't stop having that issue, to bring it back to them because it likely needed a tune.
So, the problem persisted, and I brought the car back to them for a full dyno tune. They put an SCT chip on it and did two hours of dyno tuning. Baseline run was 261, they ended up squeezing 285 out of it by the end (on a Dynojet).
So now the car runs even better. Idles perfectly, runs smoothly, etc.
EXCEPT: It still doesn't run great when it's cold, and backfires/pops out the exhaust and has significant hesitation until it warms up. Once it's warm, it runs HARD, pulls smoothly throughout the RPM range, etc.
I feel like this is an issue they should have resolved. The car shouldn't be popping and sputtering when it's cold like this.
I did some quick looking on the forums and people said they had this issue and it was either the ECT, ACT, or the BAP, or dirty injectors that needed cleaning
The car does not have a check engine light on. I am getting intermittent "low coolant" lights on the dash (it's illuminated about 75% of the time), despite the coolant level being adequate. Also checked the coolant system for leaks via pressurizing the radiator, and it seems file. The car does not have an EGR or any other emissions equipment.
This is clearly an issue with a sensor or something when the car is in open loop before it warms up. The car runs quite well when it's warm, and pulls hard.
What do you guys think?