Thread: 4th Gear Surge

Its just one problem after the other with this car

After replacing the short block due to low oil pressure i was finally able to test the transmission i rebuilt myself.

Mods on the tranny are as follows: 3.29 gear with 7/8th chain, hardened 4th gear shaft, and intense shift kit.

Everything work great except the surge i get in 4th gear. With the Tech 2 im able to command the TCC solenoid; and in 3rd gear it works flawlessly under any load.

But in 4th gear whether im commanding the solenoid on or off im constantly getting the surge at any load. Btw without commanding the TCC solenoid, it doesn't go above 50% duty cycle

Also i noticed in the adaptation tables, two of the readings were out of whack. (this is after resetting all tables)

Steady State TAP 4GR : 93.98 psi
Steady State TAP 4GR/TC : 10.00 psi

Only thing i haven't gotten to is to hooking up a pressure gauge to the trans.

I am completely sure that the surge is not a misfire from the engine, but for good measure i cleaned the MAF and ran seafoam through the engine.

Right now im leaning towards improper install on some seals but i sure hope not

Likely its the failing motor

Which motor are you referring to?

Read incorrectly. Sorry... thought the motor was still on it's way, not already replaced.

Hows the tune up on the motor, everything fresh and new?

Everything tune up wise is less then a year old.

Although I do have a P0171: system too lean(bank 1), but i believe this is due to to crankcase being vented to atmosphere, this is only temporary until i have to tools to tap the throttle body.

I didn't think this could be the issue as the fuel trim is near perfect under load and only lean at idle; also there is no misfire shown on the tech 2.

Could it be an ignition issue? Check all the plugs, wires, coils, and ICM.

Ill only have access to tools on the weekends so any troubleshooting is on hold...

But for now im just trying to get some ideas together as to what things i should focus on.

Btw how would i test the ICM?

I don't remember exactly, but I think you need a multimeter and check the output on the prongs of the ICM. Hopefully someone else will chime in with concise help.

Well doing some more snooping around i cam across this thread: http://www.grandprixforums.net/remov...ects-4907.html

I have p0300 disabled which might be the reason im not seeing individual misfires on the scanner, so this whole thing could just be a misfire ....hopefully.

So ill report back Saturday night after doing a thorough inspection, thanks everyone

Well took it on the expressway with the tech 2.
By commanding the PCS to .6 amps the surging goes away, anything lower and there is surging so its definitely trans related.

I had the pressure gauge hooked to the trans and its within specs.

I haven't really looked into it but is it possible to control the amperage via a switch?
Or am I able to tune the pcm to have lower amperage in 4th gear?

Another thing i noticed is when during a 3rd gear WOT, the PCS amperage starts at around .9 and it feels as if the engine is cutting timing,
after about a second the amperage drops to .5 and i get full power back.