wierd two step action.

[Brer Rabbit]

I let a buddy drive my car (I know big mistake) and when he brought it back the car was acting like it had a two step as soon as u applied a lil throttle. I was able to get the car home, thinking it was a headgasket and after doing a compression test, I ruled that out. Put a new set of plugs in since I thought it was due to all the race fuel I ran through the motor, but the two step action is still there. Its more like the motor is hitting a rev limiter but its happening at about 2200rpms. My coilpack and module has about 1,500 miles on it and they are new GM, so I really dont think thats the problem, but Im gonna swap it out with a known good one thursday or friday. Incase my description isnt clear enuff, I remember that the GM 3800 motors hit a rev limiter around 4000 RPMS when the car is in park, to keep from blowing them up, thats pretty much what my car is doing but only at 2200? Any suggestions would help. Thanx for lookin at this.

 

[Dreamcar86]

Do you have a scantool? If so have you ran through all the simple things to make sure everything is in check before moving on to more complex issues?

 

[Brer Rabbit]

Yeah I should have put that part in.

I have a bigstuff 3 and everything checked out. We did have to reset the TPS but other than that, everything was where it should be.

 

[Dreamcar86]

I have a bigstuff 3 and everything checked out. We did have to reset the TPS but other than that, everything was where it should be.

Well, that is where I was going with that and you have covered it. I think it is time to bring in a bigger dog at this point. I have no experience with a big stuff 3 programming but it almost sounds like there is something wrong there in one of the parameters. Sorry for not being much help here.

 

[Brer Rabbit]

Your help is always appreciated.

Thanx for trying.

 

[Dreamcar86]

Thanx for trying.

I appologize for not being much help but please post when you figure it out. Is seems at one time or another we all cross these bridges. All part of the fun of owning a GN.

 

[Brer Rabbit]

Update.

Put on a known good coil pack and module from a buddys car, and car still does the same thing. . Any other suggestions.

 

[Razor]

Upload an old file known to be no issues with.

make sure the crank sensor didnt get hit/moved.

Confirm proper air fuel ratio when problem happens. Anything 11.0-13.0 should be fine. Just making sure its not going 15:1

Broken plark plug?

Burnt plug wire?

Blew hose of off 3 bar sensor?

Coolant temp sensor?

TPS sensor?

Confirm all sensors and datalog it.. play it back at your leisure and see whats seems to be dropping out.

Wish there was more.. brain aint happening

 

[jasjamz]

Did you check intercooler hoses?

 

[Razor]

Did you check intercooler hoses?

BS3 is speed density. Wouldnt matter. If it was a MAF system.. then absolutely YES.

You can run a speed density car without anything in front of the TB.

 

[Brer Rabbit]

Checked everything visually.

Everything is connected, so at this point Im gonna take the car to a buddys shop. Bad thing is I whipped him at the track with this car so I think hes gonna get even on the bill!

 

[Brer Rabbit]

And the dumbass award goes to me!

Looks like the problem I was having is simply a burned ground wire on the header...the one that goes from the battery to the front of the block. Unfortunately I cant confirm for sure because I took the fuel pump off the car a few weeks ago. Oh well, as soon as the spring gets here I will know for sure, but at this point I feel much better about this car. Thanx to all who posted with suggestions. I love U guys man!:biggrin: