Poor Performance and Erratic Idle
Thread Starter
|
New User
Joined: Oct 2002
Posts: 2
Likes: 0
From: texas
Poor Performance and Erratic Idle
Hi All,
I could really use some advice to a problem I am having with my stock 1989 Ford F-250 with a 351 V8. It runs very poorly under load such as when I gun the engine, pull my boat, or go up hills. It does this consistently.
In addition, on an intermittant basis, it has an irregular idle. I will be stopped at a light and it revs all by itself, as if I'm pressing on the accelerator.
A few weeks ago, the engine stalled out and would not turn back on. Eventually, it started again and it has been running ok (still running poor, but not stalling out) since then.
The check engine light is not on. I took into the neighborhood garage and they checked the fuel pump and spark and said both are good. They couldn't figure out the problem and told me to bring it back when the problem repeated itself. The only thing I have changed so far is the fuel pump. Obviously, this did not fix my problem.
I've checked the archives without success. Can anyone offer any advice?
Many thanks,
Mario
I could really use some advice to a problem I am having with my stock 1989 Ford F-250 with a 351 V8. It runs very poorly under load such as when I gun the engine, pull my boat, or go up hills. It does this consistently.
In addition, on an intermittant basis, it has an irregular idle. I will be stopped at a light and it revs all by itself, as if I'm pressing on the accelerator.
A few weeks ago, the engine stalled out and would not turn back on. Eventually, it started again and it has been running ok (still running poor, but not stalling out) since then.
The check engine light is not on. I took into the neighborhood garage and they checked the fuel pump and spark and said both are good. They couldn't figure out the problem and told me to bring it back when the problem repeated itself. The only thing I have changed so far is the fuel pump. Obviously, this did not fix my problem.
I've checked the archives without success. Can anyone offer any advice?
Many thanks,
Mario
Tuned
Joined: Jun 2001
Posts: 266
Likes: 0
Poor Performance and Erratic Idle
>Hi All,
>
>I could really use some advice to a problem I am having with
>my stock 1989 Ford F-250 with a 351 V8. It runs very poorly
>under load such as when I gun the engine, pull my boat, or
>go up hills. It does this consistently.
>
>In addition, on an intermittant basis, it has an irregular
>idle. I will be stopped at a light and it revs all by
>itself, as if I'm pressing on the accelerator.
>
>A few weeks ago, the engine stalled out and would not turn
>back on. Eventually, it started again and it has been
>running ok (still running poor, but not stalling out) since
>then.....
I'm betting on the carb - perhaps needs a rebuild...
>
>I could really use some advice to a problem I am having with
>my stock 1989 Ford F-250 with a 351 V8. It runs very poorly
>under load such as when I gun the engine, pull my boat, or
>go up hills. It does this consistently.
>
>In addition, on an intermittant basis, it has an irregular
>idle. I will be stopped at a light and it revs all by
>itself, as if I'm pressing on the accelerator.
>
>A few weeks ago, the engine stalled out and would not turn
>back on. Eventually, it started again and it has been
>running ok (still running poor, but not stalling out) since
>then.....
I'm betting on the carb - perhaps needs a rebuild...
Junior User
Joined: Jan 2002
Posts: 65
Likes: 0
From: USA
Poor Performance and Erratic Idle
I had an 88 model F150 that had EFI. If yours has it also, instead of a carb, your first thing to rule out is your TPS (throttle position sensor), usually two screws, and a plug, about $30 or so. If you have a good book on your truck, like a Haynes or Chilton, it gives you the test procedure to check many of the sensors like the TPS.
Many sensors can simply be out of range and send bad data to the processor and still not cause a fault light.
Good luck
Mark
Many sensors can simply be out of range and send bad data to the processor and still not cause a fault light.
Good luck
Mark
Elder User
Joined: Oct 2002
Posts: 743
Likes: 1
Poor Performance and Erratic Idle
Sounds like an Idle Air Control valve problem. Or maybe an EGR problem. Find these on your motor and clean them according to the repair manual instructions. Either of these things can get carboned up and cause your problem.
Thread Starter
|
New User
Joined: Oct 2002
Posts: 2
Likes: 0
From: texas
Poor Performance and Erratic Idle
Hey Guys,
Thanks for all of the advice. I do have EFI so it really sounds like this may be my problem. I bought the Chilton manual at Autozone but this doesn't have anything at all on EFI.
Any ideas for a better aid to help with troubleshooting this problem?
Thanks,
Mario
Thanks for all of the advice. I do have EFI so it really sounds like this may be my problem. I bought the Chilton manual at Autozone but this doesn't have anything at all on EFI.
Any ideas for a better aid to help with troubleshooting this problem?
Thanks,
Mario
