Thanks for the explanation, I was reading some rather technical info on another web page that someone turned me on to, and it was getting out of my reach.

 

Not entirely true, it does not require a tech 2 to flash a new PCM, input your vin and synch it with your BCM. EFI LIve can do this so i assume that HP tuners may be able to as well.

 

Well guys, after 5 weeks, jeff and the guys at CAM are telling me that they may need to replace the entire wiring harness due to battery acid that got into the wiring harness. I guess the previous owner failed to mention that too. Anyone ever taken on this task ? How much of a pain was this and how long did it take you ?

 

Scott, PM sent.

 

OK guys, 9 weeks that the guys at CAM have had my car and they are totally stumped. They have replaced the BCM and PCM. They have replace the wiring harnesses to the O2 sensors, and still no progress. They say that they have checked all grounds on the car, but this still seems to me that it has to be a simple gound or poor connection issue.
Any ideas here, the guys at CAM seem to be totally lost and I am beginning to question their ability to solve this problem. The car is still doing the exact same thing as always, starts sometimes and runs fine for a little while then starts running rough and stalls. Then it won't start at all for a while, then goes back to starting and running ok for a little while. We have noticed that it will flood and foul the plugs when it won't start, indicative of a lack of spark problem.

Could this have anything to do with the cranks shaft position indicator, and if so why doesn't it throw a code ?
How about the camshaft position sensor ?
Could this be a VATS issue?

Work has kept me out of town a lot over the past couple weeks, but I intend to go get the car soon and tackle this problem myself soon.

 

I FEEL YOUR PAIN! CALL ME! PM SENT!

Bill Curlee

 

Here are some things that I have observed! The car is haviing an issue with something that doesnt cause a major system DTC. Those things are:

--Secondary Ignition (spark, spark plugs, wires, coil, poor combustion, lack of fuel)

I agree that you could still have a ground issue. Check the following Chassis and engine grounds! G-104 ,105 106, 107.



G-104 is here:



G-105 is on the drivers side of the engine block directly below cylinder #3/#5

G-106 is on the passengers side of the engine block near the starter.

G-107 is here:



Look on the back of the drivers cylinder head. There will be TWO black wires with white stripes together like lamp cord. They terminate in a single eyelet and bolt to the back of the head.

I have seen a simular issue where the special fuel line safety retainer on the engine fuel line to fuel rail connection (its VERY sharp!!) cut and shorted out the engine control harness. Follow the wiring harness that runs down the drivers side of the intake manifold. Inspect it very closely!! Look for any cuts, tears ot rubs. Theres also a metal bracket at the back of the fuel rail that the harness bends around. It often gets cut there also.







Bill Curlee

 

I mentioned all those things to Jeff Bill.............I hope he checked them!

 

My buick would have the same problem as your vette, run for like an hour and shut off.

Problem was heat related. Turned out to be a bad crank sensor.

Also have you been clearing and rechecking what codes occur at each shutdown ?

 

Ah............has this car had a leaky battery???

 

Scott, Bill Curlee pointed out the G107 ground, it's hard to check. When I changed cylinder heads, I changed the attachment position of
G107 from the back of the cylinder head to some where else because it's impossible to get to, unless the head is lifted up and moved forward.
The position that I moved it to wasn't a good ground and the engine wouldn't start until I moved G107 to a good ground.
You could have a loose/bad intermittent G107 ground, especially since the heads were removed and replaced.

Cheers, Curt

 

G-107 can be accessed, checked and tightened if necessary with the head intact! Its a little tough but yes it can.

Bill

 

Gentlemen,
Grounds: I personally checked grounds G101 thru G104 that Bill identified. When I checked them I removed them, cleaned them with a dremmel tool and wire wheel that comes with the dremmel tool, and reinstalled them. However, grounds G105 thru G107 I did not, as for the guys at CAM, they said that they did, but I cannot verify this nor what they consider "checking" them.

Battery: Yes, at one point the battery in the car must have leaked with a previous owner. There was some damage to a couple of wires, but nothing that I consider to be excessive. I have seen worse wires on some of the 30+ year old street rods I've restored that worked just fine. The guys at CAM did repair one of the wires that I saw when I stopped by the shop last time. The rest were left alone, and from what I inspected, seemed fine. I have seen what a blown up battery can do, and this was not on the excessive side of the carnage I have seen from a bad battery problem.

Thanks for the open minds guys.

 

Guys, I'm just posting this reply to keep the guys that have been helpful so far informed as to the status on my car, which I don't have back yet. I have had a long conversation with Jeff at CAM about how to proceed with the repair of my car. Jeff felt certain that the root of the problem is in a damaged wiring harness. We agreed that I would come get the car and replace the wiring harness in the car if they deemed it to be the culprit for the stalling issue, which I expected to do last week. However, what I didn't know was that when they did the BCM swap there was an error in the download that I was unaware of. This meant that nothing worked, ie, the headlights, gauges, seats, nothing, and of course the car would not start. They tried loading the unit using the VIN # and it simply would not work. To make matters worse, they had given the old BCM back to me and I wasn't made aware of this until after I had shipped the original one back to GM Partshouse for the core refund. I ended up having to get Gene to ship the original one back to me so that they could retrieve the data off of it and load the new one. They used the tech 2 to ask the old bcm for it's info, then took that info to the SPS system to down load info for the new BCM. According to Jeff, once the new BCM was properly installed the car started for a short time. So, at this point I'm waiting for them to be certain that the car is at least back to where it was when I brought it to them not worse, and that they are confident the problem lies in the wiring harness, which I hope is soon. Talking to Jeff, one good thing is that they haven't just loaded a bunch of time into the car doing wasteless work running up a bill, and he's concious of this. As soon as I get any updated info, you'll know. Lesson learned here: NEVER RETURN A CORE UNTIL YOUR SURE THE NEW PART IS IN AND WORKS.

 

any of the lastest on your car ?Was it the harness that they were able to replace fix the issues u were having with it ?

 

yep. Jeff and the guys found a wire that was corroded at the buss plug just below the battery that had poor continuity. They bypassed the plug and directly connected the wire. They also got a clean program onto the BCM and TADAHHH !!! running again. I picked it up and have driven it a bunch since then with no problems, (fingers crossed). They said that at some point I should consider changing the wiring harness, but for now to just enjoy the car. Thanks for the help guys, Todd, thanks for the reminder to update everyone.

 

Glad to see you got the car back and running properly. Sometimes the little things make us really crazy. Enjoy your ride!

 

Glad to see they found the problem, how is she running?