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Some background info. My 86' C4 has had some issues with stalling and surging in the past. I pulled code 33 and cleaned my MAF. Then after a few weeks I pulled code 42 (Electronic Spark Timing malfunction).
Recently, on a drive home I got some stalling issues and a service engine soon light. I stopped at a stop sign and smoke poured out of my hood on the passenger side. Stopped in the road and opened the hood to find a small fire on what I think is an exhaust pipe. The picture is where the fire was.
I was able to blow it out and drive home (25 miles) without further issue. Next day I drove to the other side of town (2 miles). When I got home there was smoke coming from the same spot, but no fire. After watching it a bit the smoke stopped but im a bit worried im going to burst into flames.
Both times this has happened I have had no issues with coolant or oil temp and my oil was changed about 2 weeks prior to the first fire. Also I checked my oil and it is at a perfect level.
Any ideas? The fire was just under the white heat protector you see. Toward the bottom of the engine.
is that common in C4's? And is it a pain to replace it without a shop?
also, is there any way a code 42 could have any connection with a valve cover gasket leak?
Last edited by Chamme10; Dec 27, 2020 at 10:10 PM.
is that common in C4's? And is it a pain to replace it without a shop?
also, is there any way a code 42 could have any connection with a valve cover gasket leak?
Valve cover and China Wall? IMO, pretty common. I'd definitely clean everything off and dump some dye. It is difficult or easy depending on your facilities. Out in the driveway in WI today? FAWK NO. In a heated garage, sure. You may be able to loosen the AC bracket enough to get the compressor to tilt forward enough to move the VC. I'd take the VC out and check it for straightness, clean the head and use a new gasket. Some have suggested using some RTV, others say no.
Edit. I don't know if this works without removing the AC compressor since I have a HSR intake and no AIR tubes. YMMV. You might have to remove the AC compressor enough that you can get at it and not have to discharge the thing.
From: Liliha Bakery stuffing my face with coco puffs!
I see Bosch III injectors...some people have had issues with the way these injectors seal as they are shorter than stock and do not use some sort of retention clip. Bosch III + o-rings
I see Bosch III injectors...some people have had issues with the way these injectors seal as they are shorter than stock and do not use some sort of retention clip. Bosch III + o-rings
IDK how the retention clip works for sealing. Doesn't the rail push down on the injectors? I thought they were there for assembly lines? I haven't had them in my car since a long while ago when I had the 383 installed.
Aklim is right, the clips do nothing. You do need to double up on the o-rings as shown. I find it odd that you had a fire. Usually oil dripping on a hot manifold will smoke, but not reach the ignition flash point. I suspect your spark timing issue is causing your engine to run lean making the exhaust very hot. This page from the SM may help:
Valve cover and China Wall? IMO, pretty common. I'd definitely clean everything off and dump some dye. It is difficult or easy depending on your facilities. Out in the driveway in WI today? FAWK NO. In a heated garage, sure. You may be able to loosen the AC bracket enough to get the compressor to tilt forward enough to move the VC. I'd take the VC out and check it for straightness, clean the head and use a new gasket. Some have suggested using some RTV, others say no.
Edit. I don't know if this works without removing the AC compressor since I have a HSR intake and no AIR tubes. YMMV. You might have to remove the AC compressor enough that you can get at it and not have to discharge the thing.
I forgot to mention the smoke was white and there was no smell.
I forgot to mention the smoke was white and there was no smell.
I suggest you check your fuel pressure. Turn the key on and it should pressurize and see if it holds. If it doesn't, does it drip out? I wonder if the O-rings on the fuel rail are leaking?
Its possible. I guess I'll check the tubes that run across the top of the pipe. Im hoping I have a tranny or coolant leak that dripped on the hot exhaust
When I had the L98, oil that dripped from the oil sensor on rear of block dripped right on the heat shield over passenger side exhaust. Smoked a lot, but it had oil leak smell and could actually could see where it was dripping on heat shield. If it was coolant it would definitely have a distinct smell and would not cause a fire.
I'd lean to what a few others have said about possibly injector leak.
Last edited by CorvetteRules; Dec 28, 2020 at 01:09 PM.
is that common in C4's? And is it a pain to replace it without a shop?
also, is there any way a code 42 could have any connection with a valve cover gasket leak?
my wife burned her dodge shadow to the ground (at age 16) due to a valve cover gasket leak.
Her parents didnt have insurance and she ended up having to walk/ride her bike the rest of the sunmer.
she said she cried as her /her friend watched it burn bc she knew she’d be walking the rest of the summer
OK. Not so good then. I don't carry a fire extinguisher since I don't have any plans to use it. It starts burning, I just park and flee. Let the insurance deal with it and I can buy newer and better
Valve cover gaskets on an 86 kind of suck. You have to remove the egr pipe which isn't that bad but getting it back on is a pain. Also ac compressor doesnt have to come off, air pump does. Couple hours to do the job if you can get the egr pipe clamped on in a timely fashion.
Valve cover gaskets on an 86 kind of suck. You have to remove the egr pipe which isn't that bad but getting it back on is a pain. Also ac compressor doesnt have to come off, air pump does. Couple hours to do the job if you can get the egr pipe clamped on in a timely fashion.
I'm not sure if this is going to be true since he is a center bolt VC as opposed to the perimeter bolt VC. Mine had to move the compressor but the bolts were loosened. It didn't have to come completely off. Since he has the same system as I do, maybe? OTOH, I have a HSR and no AIR system so don't know.
Edit: I also have no EGR pipe so it might complicate things.
Small engine fire has me spooked 86'
