Over fueling problem
Thread Starter
8th Gear
Joined: May 2015
Posts: 8
Likes: 0
Over fueling problem
1985 C4 Corvette 350 5.7 TPI (Completely stock)
Car is throwing a code 43 for the ESC module...
It is over fueling really bad, black smoke coming from the exhaust pipes and has created two black mud puddles on my garage wall from unburnt fuel spewing out.
My mechanic says the timing chain has slipped and that the valves are not opening at the correct time, all of this started happening after i took the valve covers off...
Items already replaced;
Spark plugs
spark plug wires
fuel pump
fuel filter
distributor cap
distributor rotor
ECM
I just want to know what you guys think about what my mechanic is saying....
I have another friend that is telling my i bumped something when doing the valve cover gaskets, and he thinks my timing chain is just fine....
Car is throwing a code 43 for the ESC module...
It is over fueling really bad, black smoke coming from the exhaust pipes and has created two black mud puddles on my garage wall from unburnt fuel spewing out.
My mechanic says the timing chain has slipped and that the valves are not opening at the correct time, all of this started happening after i took the valve covers off...
Items already replaced;
Spark plugs
spark plug wires
fuel pump
fuel filter
distributor cap
distributor rotor
ECM
I just want to know what you guys think about what my mechanic is saying....
I have another friend that is telling my i bumped something when doing the valve cover gaskets, and he thinks my timing chain is just fine....
Pro
Joined: Nov 2014
Posts: 527
Likes: 23
From: Mishawaka Indiana
1985 C4 Corvette 350 5.7 TPI (Completely stock)
Car is throwing a code 43 for the ESC module...
It is over fueling really bad, black smoke coming from the exhaust pipes and has created two black mud puddles on my garage wall from unburnt fuel spewing out.
My mechanic says the timing chain has slipped and that the valves are not opening at the correct time, all of this started happening after i took the valve covers off...
Items already replaced;
Spark plugs
spark plug wires
fuel pump
fuel filter
distributor cap
distributor rotor
ECM
I just want to know what you guys think about what my mechanic is saying....
I have another friend that is telling my i bumped something when doing the valve cover gaskets, and he thinks my timing chain is just fine....
Car is throwing a code 43 for the ESC module...
It is over fueling really bad, black smoke coming from the exhaust pipes and has created two black mud puddles on my garage wall from unburnt fuel spewing out.
My mechanic says the timing chain has slipped and that the valves are not opening at the correct time, all of this started happening after i took the valve covers off...
Items already replaced;
Spark plugs
spark plug wires
fuel pump
fuel filter
distributor cap
distributor rotor
ECM
I just want to know what you guys think about what my mechanic is saying....
I have another friend that is telling my i bumped something when doing the valve cover gaskets, and he thinks my timing chain is just fine....
I would have to agree with your friend. Check the basics and look over everything you did.
Team Owner
Joined: Jul 2004
Posts: 28,331
Likes: 3,245
From: Hartford WI
ARE YOU SURE that you put all the hoses and connectors back where they should be? If so, fine. CHECK AGAIN. Make sure you haven't forgotten to connect back something and/or have a loose hose. Hook up scanner. Does it show anything for MAF? I don't have MAF so I can't tell you what you should see but someone should know. Also, I would take the valve covers off again and see if you have a rocker loose or something just to be safe.
If you can see what the ambient air temp and coolant temp is and that the MAF is changing when you hit the gas, you might have something. I forgot what my pulse width is when it was stock so that might be a clue. Could your injectors not be hooked up on the driver side hence making the ECM think that the car is running lean and thus dumps fuel? I had that years ago and the O2 sensor reading was very lean and the ECM tried to dump fuel into the car
If you can see what the ambient air temp and coolant temp is and that the MAF is changing when you hit the gas, you might have something. I forgot what my pulse width is when it was stock so that might be a clue. Could your injectors not be hooked up on the driver side hence making the ECM think that the car is running lean and thus dumps fuel? I had that years ago and the O2 sensor reading was very lean and the ECM tried to dump fuel into the car
Last edited by aklim; Dec 23, 2015 at 05:36 PM.
Instructor
Joined: Nov 2013
Posts: 154
Likes: 1
I wanna say that esc is electronic spark control and I believe there is an ignition control module under your distributor cap also under the rotor, looks like it's part of the base of the distributor with wires going to it. You can see it if you pull the distributor cap. This is important for timing the injectors and ignition and can go bad or maybe you disturbed some wires under there when you removed the cap. I've also seen he little wires to the in module get corrodid and break. Seeing as how it's basically throwing a code for that part it check that first, heck replace it anyways its a pretty cheap part.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
There are two ways to get an error code 43. Too bad GM didn't separate them with different numbers, but it is what it is.
When you start the engine the ECM adds an extra 20° of advance. That causes knocks. The ECM looks for at least two knocks and then resets the spark advance back to normal. If it does NOT see at least two knocks it sets error code 43. This checks that the ESC module is functioning correctly.
When the engine is running the ECM will set error code 43 if it sees less than 6 volts from the ESC module. Normally it's about 7 volts or slightly more.
This ECM waveform shows the two knocks at startup and the steady 7-8 volts after that:
Basically, what all this is telling you is that your ESC module (or the wiring associated with it) is bad. You might have a problem with the knock sensor (or its wiring/connector)
When you start the engine the ECM adds an extra 20° of advance. That causes knocks. The ECM looks for at least two knocks and then resets the spark advance back to normal. If it does NOT see at least two knocks it sets error code 43. This checks that the ESC module is functioning correctly.
When the engine is running the ECM will set error code 43 if it sees less than 6 volts from the ESC module. Normally it's about 7 volts or slightly more.
This ECM waveform shows the two knocks at startup and the steady 7-8 volts after that:
Basically, what all this is telling you is that your ESC module (or the wiring associated with it) is bad. You might have a problem with the knock sensor (or its wiring/connector)
Last edited by Cliff Harris; Dec 23, 2015 at 11:37 PM.
Team Owner
Joined: Jul 2004
Posts: 28,331
Likes: 3,245
From: Hartford WI
There are two ways to get an error code 43. Too bad GM didn't separate them with different numbers, but it is what it is.
When you start the engine the ECM adds an extra 20° of advance. That causes knocks. The ECM looks for at least two knocks and then resets the spark advance back to normal. If it does NOT see at least two knocks it sets error code 43. This checks that the ESC module is functioning correctly.
When the engine is running the ECM will set error code 43 if it sees less than 6 volts from the ESC module. Normally it's about 7 volts or slightly more.
This ECM waveform shows the two knocks at startup and the steady 7-8 volts after that:
Basically, what all this is telling you is that your ESC module (or the wiring associated with it) is bad. You might have a problem with the knock sensor (or its wiring/connector)
When you start the engine the ECM adds an extra 20° of advance. That causes knocks. The ECM looks for at least two knocks and then resets the spark advance back to normal. If it does NOT see at least two knocks it sets error code 43. This checks that the ESC module is functioning correctly.
When the engine is running the ECM will set error code 43 if it sees less than 6 volts from the ESC module. Normally it's about 7 volts or slightly more.
This ECM waveform shows the two knocks at startup and the steady 7-8 volts after that:
Basically, what all this is telling you is that your ESC module (or the wiring associated with it) is bad. You might have a problem with the knock sensor (or its wiring/connector)
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Team Owner
Joined: Jul 2004
Posts: 28,331
Likes: 3,245
From: Hartford WI
I suppose you can check the wiring and make sure that it is attached. I'm not sure but maybe a crazy stupid idea is that it is reducing advance so much it doesn't ignite properly? Crazy enough that I would think I am crazy for thinking of it. Have you seen what the scanner says? Have you cleared the code and see if it comes back? I had a problem with an OBD 2 car with P0133. All things pointed to the front O2 sensor. Swapped MAF, plugs, wires, injectors, after we replaced the front O2 sensor. Nothing worked. Rear O2 sensor was supposed to be monitoring the efficiency of the cat converter. CEL came back every time after 20 mins or so of driving. As a "Hail Mary", we changed the rear O2 sensor. Never came back. Swapped it back, it came back, swapped to new and it was fine again.
Team Owner
Joined: Jul 2004
Posts: 28,331
Likes: 3,245
From: Hartford WI
I forgot the codes I was getting but I pinched the wire on the injector harness doing the valve covers eons ago. Injector bank shorted out and stopped firing. Car ran pig rich and we noticed the huge jump in pulse width. Fixed wire and car ran right again. You were playing with the harness. Maybe a pinched wire? Check with scanner.
Drifting
Joined: Feb 2008
Posts: 1,535
Likes: 177
From: NE Ohio
2024 C4 of the Year Finalist - Unmodified
Team Owner
Joined: Jul 2004
Posts: 28,331
Likes: 3,245
From: Hartford WI
It's possible but why does that happen? All he did was pull the valve covers. How did it affect the FPR? Kinda why we should check what the scanner says as to whether there is an air leak, injector pulse width massively changed, etc. It could be the FPR and he should verify that with a gauge. I also think he should check the timing in case he bumped the thing.
Drifting
Joined: Feb 2008
Posts: 1,535
Likes: 177
From: NE Ohio
2024 C4 of the Year Finalist - Unmodified
It's possible but why does that happen? All he did was pull the valve covers. How did it affect the FPR? Kinda why we should check what the scanner says as to whether there is an air leak, injector pulse width massively changed, etc. It could be the FPR and he should verify that with a gauge. I also think he should check the timing in case he bumped the thing.
I just shut mine off at a car show (running perfect) an started it to leave and and bearly got home.
Team Owner
Joined: Jul 2004
Posts: 28,331
Likes: 3,245
From: Hartford WI
Team Owner
Joined: Jul 2004
Posts: 28,331
Likes: 3,245
From: Hartford WI
Team Owner
Joined: Jul 2004
Posts: 28,331
Likes: 3,245
From: Hartford WI