Couple of hard start problem
Thread Starter
Burning Brakes
Joined: May 2001
Posts: 1,036
Likes: 0
From: Plant City Fl
Couple of hard start problem
Just got my motor back together after fixing a valve problem. But now when the motor is cold its hard to start. I have to turn it over a couple times, stop give it some gas, turn over again, repeat this three or four times before it will start. After the first time you start it and warm up the engine it starts right up no problem. I have all new fuel injectors and I can hear my fuel pump run when I initially turn the key on. Fuel pressure is 47 psi. All my mods are in my signature.
The other problem on startup is a surging idle, goes back and forth from 900-12 or 1300 for 15 or 20 seconds. Its like its searching for the right idle speed. After 15 or 20 seconds the idle settles down and it is ok until I start the car again. It does this even when I start the car when it is warm, although only for a few seconds.
Any ideas??? Thanks in advance.
The other problem on startup is a surging idle, goes back and forth from 900-12 or 1300 for 15 or 20 seconds. Its like its searching for the right idle speed. After 15 or 20 seconds the idle settles down and it is ok until I start the car again. It does this even when I start the car when it is warm, although only for a few seconds.
Any ideas??? Thanks in advance.
Racer
Joined: Oct 2007
Posts: 250
Likes: 1
The surging sure sounds like a vacume leak.Spray carb cleaner or starting fluid around all the places a vacume leak can occur(hoese and gaskets etc.) with the engine running. If/when the engine surges, you found it.
Take Care, -John
Team Owner
Joined: Jan 2003
Posts: 20,314
Likes: 245
From: Summerland B.C. Canada
Just pointing out possibilities.
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Thread Starter
Burning Brakes
Joined: May 2001
Posts: 1,036
Likes: 0
From: Plant City Fl
Reset the idle, set the tps voltgage and that seemed to help a little. Stiill get some surging on startup that goes away in 20-30 sec. I checked everywhere I could think of for a vacuum leak, intake, runners to intake runners to plenum, plenum cover, vacuum lines. Any ideas on where else I should look for a leak. Thing runs great once the surging stops, but its a real pita because it does it every time you start, hot or cold.
Haven't had a check engine light, so no codes.
Thanks for the help guys.
Haven't had a check engine light, so no codes.
Thanks for the help guys.
Thread Starter
Burning Brakes
Joined: May 2001
Posts: 1,036
Likes: 0
From: Plant City Fl
Found a vacuum line unplugged. There's a little junction box (for lack of a better description) bolted to the thermostat housing. It has four vacuum lines and a small electrical plug on top of it. One of those lines was disconnected. Only way I could get the line back on it, was to remove the junction box from the thermostat housing and pull it out from under the plenum. I got all the lines reconnected, but still have the surging problem. Does that metal bracket with the vacuum lines and the electrical connection have to be grounded? Is that why it was bolted to the thermostat housing?
Team Owner
Joined: Jan 2003
Posts: 20,314
Likes: 245
From: Summerland B.C. Canada
That's the EGR solenoid and no, it doesn't need to be grounded. Now that you found a vacuum leak, maybe another min idle/TPS adjustment is needed.
http://members.shaw.ca/corvette86/EGR%20System.pdf
http://members.shaw.ca/corvette86/EGR%20System.pdf
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Yeah, that is the EGR solenoid. It should have three vacuum "looking" lines on it. I know there are differences in year models with vacuum lines. My 86 has one vac port under the throttle body that runs to one side of the solenoid. On that same side, one vac line runs from the solenoid to the EGR. The opposite side of the solenoind has one vac line that doesn't go to anything. I believe there was some type of filter on the end of it from the factory. Seems like I remember someone saying there were two vacuum ports on some of the later throttle bodys.
I would ground the ALDL and see if any code is there anyway. If no codes, you will need to check things that don't cause codes.
I would ground the ALDL and see if any code is there anyway. If no codes, you will need to check things that don't cause codes.