1986 vette idles iratic
Thread Starter
Intermediate
Joined: Jul 2009
Posts: 38
Likes: 0
1986 vette idles iratic
My 1986 vette idles iratic between 400-1000 when warmed up it also has a hard time starting after it gets hot and is shutt off for like 10 mins, i also have to pump the gas when its cold to get runing almost like its carburated, what do you guys think?:
Pro
Joined: Jun 2001
Posts: 520
Likes: 6
From: Elverson PA
I think you may want to check out the fuel pump relay on the starting issue, but usually that will throw a check engine light when you finally get it started. You could also have a big vacuum leak. I would check that out with some 2+2 carb cleaner spray. Spray down the gaskets on the TPI. If you spray a leak, it will run different right away.
Other than that, as Agent 86 said, more info would really help.
Other than that, as Agent 86 said, more info would really help.
Thread Starter
Intermediate
Joined: Jul 2009
Posts: 38
Likes: 0
i just got the car it has a comp cam, trickflow heads, 2800 stall converter, yes im mechanically inclined this is my first fuelie though. no light is on. i was going to do a fuel pressure check tomorrow. what do you guys think.
Team Owner
Joined: Jan 2003
Posts: 20,333
Likes: 263
From: Summerland B.C. Canada
You might want to start with checking/setting the minimum idle and throttle position sensor.
http://willcoxcorvette.com/instructi...5-89_new_2.pdf
Have you checked the base timing, should be 6* BTDC with EST wire disconnected.
http://members.shaw.ca/corvette86/Ig...System-EST.pdf
Your hard starts could be a result of a leaky injector(s) or a overheated ignition module. Testing fuel pressure and pressure loss, would also be beneficial. Also, pull the vacuum line off fuel reg and check for signs of gas.
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
Have you checked for stored codes in ECM ??
http://members.shaw.ca/corvette86/No...it%20Check.pdf
Have you had a close look for vacuum leaks ??
Does it have a custom PROM ??
Did you know about the problem before you bought it, or did they suddenly appear ??
http://willcoxcorvette.com/instructi...5-89_new_2.pdf
Have you checked the base timing, should be 6* BTDC with EST wire disconnected.
http://members.shaw.ca/corvette86/Ig...System-EST.pdf
Your hard starts could be a result of a leaky injector(s) or a overheated ignition module. Testing fuel pressure and pressure loss, would also be beneficial. Also, pull the vacuum line off fuel reg and check for signs of gas.
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
Have you checked for stored codes in ECM ??
http://members.shaw.ca/corvette86/No...it%20Check.pdf
Have you had a close look for vacuum leaks ??
Does it have a custom PROM ??
Did you know about the problem before you bought it, or did they suddenly appear ??
Thread Starter
Intermediate
Joined: Jul 2009
Posts: 38
Likes: 0
It was like this when i bought it i thought the surging was from the aftermarket cam i didnt noitce the restart promblem till later, i cleaned the throttle body and iac valve it idles better now it surges less and only surges between 6-8 and some times stays at 800 the ses light works and is not on. it has a adjustable pressure regulator. i dont have a pressure gauge though.
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Team Owner
Joined: Jan 2003
Posts: 20,333
Likes: 263
From: Summerland B.C. Canada
Does it come on as soon as engine is started, or at a certain temp ??
If it has an aftermarket PROM, it may be programmed to cool to a number that is hard to maintain in summer heat.
http://members.shaw.ca/corvette86/Co...%20Control.pdf
If it has an aftermarket PROM, it may be programmed to cool to a number that is hard to maintain in summer heat.
http://members.shaw.ca/corvette86/Co...%20Control.pdf
Team Owner
Joined: Jan 2003
Posts: 20,333
Likes: 263
From: Summerland B.C. Canada
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Some people (like me) wire the coolant fan's relay directly to ground to make the fan to run all the time...only the thermostat controls the engine temps this way....which works well with a 190 thermostat installed. This is not a bad thing IMHO since it will allow for a more stable coolant temps.
Team Owner
Joined: Jan 2003
Posts: 20,333
Likes: 263
From: Summerland B.C. Canada
