rough idle
Thread Starter
|
Senior User
Joined: Apr 2003
Posts: 102
Likes: 0
rough idle
ok, i have a 1988 bronco with a 302 and i just replaced the engine so it's brand new. well sometimes when im idleing at a stop sign or something, itll fluctuate between 300 and 1000 rpms. sometimes itll be just fine, but other times it idles up and down and it sounds likes it's about to stall. any ideas????
David
David
Lead Driver
Joined: Sep 2002
Posts: 9,182
Likes: 12
From: Gateway to the West
Check for vacuum leaks first....then check for any codes stored in the computer. (Haynes manual describes how you can pull the codes yourself). It has the earmarks of a dead or dying IAC (Idle Air Control) solenoid but its best to check with the onboard computer before you just go arbitrarily replacing components. (Gets expensive too if you don't get the faulty component the first time).
New User
Joined: Aug 2003
Posts: 13
Likes: 0
From: Baltimore
I am not the end all authority on motors but, after a long battle with this in my Bronc it was a fuel preddure regulator. Granted I have a 351w with fuel injection so after the vacuum leak and all check the fuel pressure.
PS Get a haynes manual!!!!!
PS Get a haynes manual!!!!!
Junior User
Joined: Sep 2002
Posts: 70
Likes: 0
From: FL
My 90 did the same thing.
If I was driving down the road and I came to a light, at a stop, my idle would fluctuate. Then progressively, my truck would just stall out due to the fluctuation of idle.
I believe that the 88 models have fuel injection just like my 90. If this is the case, take greystreak92's advise - check the codes. I do not have one of these fancy things (nor the patience to count led's on a cheap model). I just replaced my TPS, throttle position sensor. After about ten miles of driving, no more problems.
I am not filthy rich by any means, but I just took a good guess.
Let us know what you find and if you should need any help with installation ideas of whatever component it turns out to be.
If I was driving down the road and I came to a light, at a stop, my idle would fluctuate. Then progressively, my truck would just stall out due to the fluctuation of idle.
I believe that the 88 models have fuel injection just like my 90. If this is the case, take greystreak92's advise - check the codes. I do not have one of these fancy things (nor the patience to count led's on a cheap model). I just replaced my TPS, throttle position sensor. After about ten miles of driving, no more problems.
I am not filthy rich by any means, but I just took a good guess.
Let us know what you find and if you should need any help with installation ideas of whatever component it turns out to be.
