90 C4 stalls after startup...need help.
Thread Starter
Instructor
Joined: May 2013
Posts: 105
Likes: 17
From: Monroe Township New Jersey
90 C4 stalls after startup...need help.
Looking for advice for friend of 90 C4. Corvette is stock. He took car to a mechanic at an auto body shop, who replaced oil pan, valve cover, and intake manifold/plenum gaskets. He used silicone for the top part of intake plenum, which I understand is correct. Used the proper gaskets for the runners. He did not wait for the silicone to dry and tried to start the engine, which blew the sealant out. He cleaned and resealed, waiting for sealant to dry Engine cranked over, but did not start. Asked me too take a look (I have a 67 small block coupe, but not to familiar with the C4's) Come to find out he removed the distributor to better install gaskets, etc. Found that the distributor was 180 degrees from normal, so pulled and placed in correct location. Engine started right up, but runs for approximately 10 seconds, then stalls. Repeated attempts to start have the same outcome. Fuel pressure is approximately 40-42 psi, no error codes. Appreciate any suggestions. Thanks
Drifting
Joined: Mar 2018
Posts: 1,362
Likes: 400
From: DFW TX
Don't get antsy here a lot of traffic occurs early in the morning and late in the evening when people aren't working.
Look at the fuel pressure at the rail and possibly that you are still a tooth or two off on the timing and it fires but settles at a timing setting that won't sustain an idle.
Look at the fuel pressure at the rail and possibly that you are still a tooth or two off on the timing and it fires but settles at a timing setting that won't sustain an idle.
Melting Slicks
Joined: Jan 2014
Posts: 2,192
Likes: 381
From: Lunenburg MA
Does the fuel pressure hold all the way to the 10 minute stop? I would guess one of three things: Loss of fuel pressure, loss of spark, or loss of injector pulses. All three are pretty easy to check for. Since you/he touched the distributor, I'd suspect at loss of spark first.
Thread Starter
Instructor
Joined: May 2013
Posts: 105
Likes: 17
From: Monroe Township New Jersey
Appreciate the responses.
Fuel pressure holds steady for quite some time, although I didn't check with a watch. Had a spark plug tester and checked all wires and they are all good, and powerful ( ask me how I know
.
Checked injector ohms, all within spec. Engine fires, runs good for 5-10 seconds, then rpms come down and dies.
Plan to check this weekend for timing, and also see if off by one or two teeth when we put distributor back. One issue is I cannot find TDC mark on crankshaft pulley. Will investigate further....it's got to be there.
Fuel pressure holds steady for quite some time, although I didn't check with a watch. Had a spark plug tester and checked all wires and they are all good, and powerful ( ask me how I know
.Checked injector ohms, all within spec. Engine fires, runs good for 5-10 seconds, then rpms come down and dies.
Plan to check this weekend for timing, and also see if off by one or two teeth when we put distributor back. One issue is I cannot find TDC mark on crankshaft pulley. Will investigate further....it's got to be there.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Engine
Actually sounds like a pllugged fuel filter
or a bad pump.
did this bodyshop guy put a 24v charger on it?
seen it happen
they charge up someone’s diesel truck and forget to switch it back
or a bad pump.
did this bodyshop guy put a 24v charger on it?
seen it happen
they charge up someone’s diesel truck and forget to switch it back
Last edited by coupeguy2001; Jul 11, 2020 at 01:25 PM.
