Balancer differences and interchange...long

[Oldsaddict]

Hello all, I am in the middle of a custom engine swap project and after weeks of agrevation and going over everything possible I stumbled onto something that I hope will help. Basically I am using a 98 Camaro pcm with a S2 3800 and 4L60E trans. The engine is built up a bit and I built a custom wiring harness for the vehicle it is in. My problem is constant misfires on every cylinder and it runs rough mainly at idle though it will rev decent and still misfire at higher rpms. There is no popping in the exhaust or intake or anything like that, just really shaky. The bottom end is an L67 from a 98 Grand Prix as is the balancer that goes with the engine. I have gone over wiring several times with my scope, check all sensors, replaced about anything as last resort testing, tore the engine back apart down to heads and block and check cam degree, compression, leakdown, running compression, pressure tested upper and lower intake..... you name it I have checked it!!!! Here are the parts that have been swapped - PCM, Crank sensor, plugs, wires, injectors, ICM, Coil packs. All voltages and grounds have been checked at all sensors/modules while not running and running. Anyways back to the balancer questions - I have a 98 GM service manual and the balancer drawings in the pictures are drastically different than the earlier ones and the fwd balancers. After doing some research it appears that 97 manual cars and all 98-02 f-body 3800 cars had a different balancer. I cannot find one anywhere and drive over 2 hours each way to pick up a used one the other day only to get there and it is the wrong one! My local dealer cannot get one for 3-5 days and nobody else has one so I dont have a picture of a real one to compare to but I know the part number is different and nobody seems to have or can find anything aftermarket. There was a thread I found on here searching and I believe it was last fall that someone put a fwd engine in his 98 camaro and it idled very rough and the balancer was brought up but he never posted a fix. Does anyone know with 100% certainty that you must use a 98+ f-body balancer with a 98 pcm? I am really out of options here and need to find a reason to my issue and until I get ahold of a balancer I wont know if it helps or not and I am having a lot of trouble finding one. Thanks all who took the time to read this and if you have any advise.

Added note- I use HPTuners and have made LOTS of changes in all directions with fueling and timing starting with some base stuff and going to extremes in different directions which has not helped.

[ssms5411]

Re: Balancer differences and interchange...long

I know my balancer on my 96' Camaro dry rotted from the inside after something like 160,000 miles on it. It made a bad knocking sound though at idle. I would just get the right part # on there so you can rule that out, also the balancer bolt is TTY.

[Oldsaddict]

Re: Balancer differences and interchange...long

The balancer on the engine is in good condition and the car the engine came out of ran perfectly fine and i am aware of the knocking noise from balancer going bad as I used to be an engine machinist and have worked on these engines for a long time. Yes I know the bolt is TTY, I am very anal about detail and everything is torqued to spec though that crank bolt is a royal PITA in the car!

[ssms5411]

Re: Balancer differences and interchange...long

Have you checked all the vac, lines , maybe that is why it is a rough idle and misfires up top? Just throwing some suggestions out there, have you put a vac. gauge on it? If so what is it idling at?

[ssms5411]

Re: Balancer differences and interchange...long

With Hptuners did you get any codes other than misfire codes?

[Oldsaddict]

Re: Balancer differences and interchange...long

Vacuum leaks have all been check and everything has been plugged off that was suspicious though no changes have been made. As I mentioned in the original post the everything was torn back apart down to heads and block and inspected. I added tons of fuel with the tuner to rule out lean being a problem and I can read 10:1 on the wideband and it makes no change whatsoever. I can also make it read 16:1 and it runs the exact same. This car has no EGR or PCV stuff on it so that can be ruled out that also. A vacuum test is not going to say anything because the car wont idle for crap, I can promise you the vacuum is terrible at idle because it runs so rough and the misfire count is through the roof on every cylinder on the scanner. The only codes, other than emission codes that have been turned off, that pop up are code P0300. I also found that when turning OFF code 300 the scanner will not display any misfires! We came across finding this out a few weeks ago with a Tech2 hooked up and the only way it will display misfires is when the code is set to factory settings in the tune. The Balancer is the only thing I have not replaced and back to the topic of this post I need to know the differences. I am not spending $125 on a new balancer to find out it makes no difference. This is not my car and is already way over budget so finding a used one would greatly help out but I am having an aweful lot of trouble with that, and a new one is going to be a 3-5 day wait which I cant afford to sit on that long. I can watch crank and cam signals with my scope going to the ICM and from the ICM to the pcm and they are fine. I tried different ignition modules and coils to rule out something screwy going on with what I started with and eveyrthing, and I mean EVERYTHING I have tried has made absolutely no change tune or parts wise which lead me to the balancer. I know it is different but to what extent other than appearance?

[ssms5411]

Re: Balancer differences and interchange...long

Don't know about the balancer, but have you tried another PCM in there or reflash the stock tune back on there and then make the changes you need again. I've had to reflash my stock tune back before because I was having some issues. Agian just trying to give some suggestions.

[Oldsaddict]

Re: Balancer differences and interchange...long

In the original post I mentioned replacing the pcm. I tried a bone stock file over quite a few times. Thanks for helping out I am open to about anything and really need to know 100% what is going on for the balancer differences.

[FirebirdGT]

Re: Balancer differences and interchange...long

Anyways back to the balancer questions - I have a 98 GM service manual and the balancer drawings in the pictures are drastically different than the earlier ones and the fwd balancers. After doing some research it appears that 97 manual cars and all 98-02 f-body 3800 cars had a different balancer. I cannot find one anywhere and drive over 2 hours each way to pick up a used one the other day only to get there and it is the wrong one! My local dealer cannot get one for 3-5 days and nobody else has one so I dont have a picture of a real one to compare to but I know the part number is different and nobody seems to have or can find anything aftermarket. There was a thread I found on here searching and I believe it was last fall that someone put a fwd engine in his 98 camaro and it idled very rough and the balancer was brought up but he never posted a fix. Does anyone know with 100% certainty that you must use a 98+ f-body balancer with a 98 pcm? I am really out of options here and need to find a reason to my issue and until I get ahold of a balancer I wont know if it helps or not and I am having a lot of trouble finding one. Thanks all who took the time to read this and if you have any advise.

http://www.tacreationsusa.com/balancers.htm

.

[Oldsaddict]

Re: Balancer differences and interchange...long

Thanks for the link! I have been having trouble finding a picture other than the drawing in the service manual. All of the junkyards that I have called that say the do have the correct one actually do not after asking them what it looks like which is making it very difficult to find one.

[Oldsaddict]

Re: Balancer differences and interchange...long

UPDATE / FIX!!!

Ok with the balancer in question I finally was able to pick one up semi locally and the 95-97 is just like the fwd balancers where the 98+ is completely different as shown in the link posted above. I took a few pics before I tried it out though it shares the exact same reluctor rings for the crank sensor in the same position so I had my doubts. Well sure enough, NO change at all which I didnt believe anyways after looking at one in hand so there is no pcm conflict with different balancers. After this it was back to square one ruling out near everything because it has all be checked meticulously the post month trying to isolate the problem. HERE is what was found and should have been tried before tearing everything back apart..... F-body pcms require a theft deterent signal from the bcm which basically says that the VATS system/correct key is being used. Without this signal the car will run for a few seconds and die. HPTuners has always said to switch from PWM to Serial in the VATS option menu when NO vats signal is being used ie a swap. WRONG!!!!!! We put a 99 grand prix pcm in for the heck of it to see if the car would run ok and it did!!! Up until 01 the grand prix pcms dont care if the signal is present or not. Last night I built a vats bypass module and hooked it up and the car now runs fine! A month of pure hell over not using a signal for the vats wire when everyone says just switch it to Serial, doesnt work. The car WILL run but very poorly. The car will also not go into closed loop at all and as mentioned above misfires terribly and runs very rough throughout the rpm range. I was able to drive the car last night for a while and it feels great to have this behind me now. I hope this will help anyone planning a swap or not running the bcm.

Dave