Hard start when warm/Idles high
Thread Starter
6th Gear
Joined: Feb 2009
Posts: 6
Likes: 0
From: Warren RI
Hard start when warm/Idles high
Hey I have an 88, I've had a problem with this since I got the car. I'll go to start it up and it cranks up right away, but if I drive around for a while until the car warms up then try to start it up again...it just cranks forever. I actually have to hold down the pedal to the floor and crank it around 5 seconds to make it start. I tested fuel pressure and it seems ok. The radiator was replaced as well as the MAF and the computer. It also idles very high...I had the TPS adjusted but it still idles very high. Any help would be appreciated.
Thanks,
Matt
Thanks,
Matt
Team Owner
Joined: Jan 2009
Posts: 73,568
Likes: 33
From: Somewhere in Mo
St. Jude Donor '09-'10, '14
If you have to hold down the peal your computer is probably sensing a flood situation.
What was your fuel pressure when you tested it, and how long did it hold pressure?
I'm not an expert but since I am going through sort of the same issues I will help get you started off until the posse arrives.
My first thoughts of a high idle are two things, vacuum leak somewhere or even the IAC could possibly be screwing up.
What was your fuel pressure when you tested it, and how long did it hold pressure?
I'm not an expert but since I am going through sort of the same issues I will help get you started off until the posse arrives.
My first thoughts of a high idle are two things, vacuum leak somewhere or even the IAC could possibly be screwing up.
Last edited by RetiredSFC 97; Jan 27, 2010 at 02:56 PM.
Melting Slicks
Joined: Mar 2008
Posts: 2,141
Likes: 76
From: Santa Maria, CA
If you have to hold down the peal your computer is probably sensing a flood situation.
What was your fuel pressure when you tested it, and how long did it hold pressure?
I'm not an expert but since I am going through sort of the same issues I will help get you started off until the posse arrives.
My first thoughts of a high idle are two things, vacuum leak somewhere or even the IAC could possibly be screwing up.
What was your fuel pressure when you tested it, and how long did it hold pressure?
I'm not an expert but since I am going through sort of the same issues I will help get you started off until the posse arrives.
My first thoughts of a high idle are two things, vacuum leak somewhere or even the IAC could possibly be screwing up.
You could have flooding from an injector leak. Loss of pressure at the fuel rails means it will take a little longer to fire. Check pressure when you shut it off to see how long it holds. If pressure drops rapidly, trying pinching off the fuel supply and return lines at the tank. If pressure still drops, one or more injectors could be leaking. I had similar starting issues. They went away when I replaced the injectors.
The high idle could be a vacuum leak.
Melting Slicks
Joined: Dec 2009
Posts: 2,226
Likes: 284
Check the engine coolant senser, the restistence of this senser changes w/ temp. The ecm uses this to detremine idle speed & fuel enrichment, on a cold engine the idle is higher & more fuel is injected, thats why EFI cars dont have chokes. I think your senser is reading cooler than what the engine is actually running.
Team Owner
Joined: Jan 2009
Posts: 73,568
Likes: 33
From: Somewhere in Mo
St. Jude Donor '09-'10, '14
Check the engine coolant senser, the restistence of this senser changes w/ temp. The ecm uses this to detremine idle speed & fuel enrichment, on a cold engine the idle is higher & more fuel is injected, thats why EFI cars dont have chokes. I think your senser is reading cooler than what the engine is actually running.
But we need to see the fuel pressure readings as well.I have known people in the past whose fuel pump was failing and this is what happened with a warm car.
