Fast Idle and intermitent starting problem
Thread Starter
1st Gear
Joined: May 2005
Posts: 1
Likes: 0
Fast Idle and intermitent starting problem
Hi,
I have a 1987 4+3 which I have used daily for over a year. Apart from the usual leaks that I had fixed and a new alternator it runs really well. However, recently when I take my foot of the gas the revs stay high and only return to the usual idle if I 'rev' the engine slightly. This happens every time I let off the gas either at standstill or driving, I've kind of got used to it as I drive it as my main transport to work but I obviously want to fix it. It has also (last couple of days) started having an occasional sarting issue. It will fire up for a second but then die, if I hold the gas pedal down half way I can then get it to rev after a couple of attempts, once running it is fine again. I don't know if these two problems are related, or if its a Throttle Body problem or sensor problem. I have checked the mechanical links and operation of the throttle cable and it doesn't stick.
Anyone got any ideas?
Thanks
Lee
I have a 1987 4+3 which I have used daily for over a year. Apart from the usual leaks that I had fixed and a new alternator it runs really well. However, recently when I take my foot of the gas the revs stay high and only return to the usual idle if I 'rev' the engine slightly. This happens every time I let off the gas either at standstill or driving, I've kind of got used to it as I drive it as my main transport to work but I obviously want to fix it. It has also (last couple of days) started having an occasional sarting issue. It will fire up for a second but then die, if I hold the gas pedal down half way I can then get it to rev after a couple of attempts, once running it is fine again. I don't know if these two problems are related, or if its a Throttle Body problem or sensor problem. I have checked the mechanical links and operation of the throttle cable and it doesn't stick.
Anyone got any ideas?
Thanks
Lee
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
The throttle hanging open, very well may be the throttle shaft bores in the TB, pot metal, casting being worn. An easy check and a temporary cure, is to clean and lube both ends of the throttle shaft on the outside of the TB. If that helps, you need to either replace the TB or have the throttle shaft bores bushed or fitted with bearings.
RACE ON!!!
RACE ON!!!
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
you may want to check your TPS as well. Ensure that it is not sticking. There is a spring assembly inside your TPS which allows it to track with the position of the TB shaft. If this is slow to return or sticking when you let off the accelerator, your idle will be high until it settles to its resting position on the TB shaft....
Now, if your '87 does not have a TPS, please excuse my ignorance.
Now, if your '87 does not have a TPS, please excuse my ignorance.
