Weird problem

[slasky]

At SDAC I did my burnout, at the track not the hotel, and when I pull up to the line the car would not go above 3K. It would go to 3k and then drop to 2k so I could not launch. Once I started moving down the track it was fine. It did the same thing next pass except it did it on the burnout too. I went to put it on the trailer and show Bucar what it was doing but it was fine.
I have driven the car a few time on the street since then and it was fine.
Last night I went to the track. And on my 2nd pass I noticed it was breaking up slightly at high RPMs. On the third pass I did my burnout and then it started the 3K surging thing again at the line. I tried wiggling some wires when I got back to the pits but it did not change anything. Finally I turned the car off and immediately restarted it and it was fine. I did my burnout, launched and all was still good. I hit second and it started breaking up big time. It ran like crap all the way down the track.
The icing on the cake was after I picked up my time slip, I drove about 10 feet before hearing a snap and having the transmission die.
Any Ideas on what could be causing the 3K limit problem? The check engine light was not on during or after the problem.

Here is what it does when it is broken:

[Lugert]

Check for the intermittent block of wood under the skinny pedal on the right.

[ScottD]

You have issues w/ burnouts don't you, I saw you do a burnout once and your hood ornament came off :-)

Did you check codes on it? Was there some axle hop on the burnout before the problems started that could have shaken something loose?

[1FastCSX289]

You probably have a wire that broken or loose....or perhaps a bad sensor. Check the codes first, wiggle test, etc. My bet would be on the TPS or TPS wiring.

[prepared]

Had a similar problem when the factory splice in the power wire feeding the MAP sensor, TPS started to come apart...

Lets see... I don't have my FSM here, but the splice was in the wire harness over near the MAP. SMEC car, btw. Would be the +5v feed, I think. Can't remember the wire color... Black/Lt Blue????

Pulled the factory splice apart and re-soldered it to solve the problem.

I DID have codes for MAP and TPS - no CEL. Seems there is another sensor fed off the same wire... might be part of the HEP if memory serves.

[OmniLuvr]

i had the exact same problem too, 3k to 2k limiter, but i believe it was something in the stock cal. it seamed that when i did a burnout and hit the rev limiter, it would do this when i would make my pass. i can only attribute my problem being the computer limiting rpm because during the burnout i hit the rev limiter for an extended period (couple seconds maybe?) and it thought that wheelspin was excessive, so it limited my power by killing the engine once it started to boost or hit that rpm. as soon as i turned the vehicle off and back on again, problem was gone until i hit the rev limiter during my burnout.

your other problem, not really sure, i had a problem like that and it turned out to be the coil, but like others have asked, any codes? what are you running for electronics (lm,smec, and/or custom cal?)?

[Pat]

It's a sensor or a connector. My car did that with a bad TPS connection. I've also seen the car act the exact same way with a map line unhooked,

[slasky]

Absolutely no codes; only 55. It really does sound like the TPS circuit acting up. If the throttle was open and the tps said it was closed it would rev up until it ran out of fuel and then drop and recover. I will have to check out the wiring on it.

[1FastCSX289]

Code 76? Gazer behind wheel?



......Ok, thats an old one.

[Darkapollo]

+1 for the TPS..

[shadow88]

You burn your own cals, right? Do you have any "know good" cals, or even the stock one?

What happened to the transmission?

[urban]

I did same problem last summer, bad connection on throttle body, I weld wire and everything fine...

[Aries_Turbo]

he is running something i did for him. been running it for years with no problems till now.

sounds like its the TPS or TPS wiring like everyone is saying.

Brian

[shackwrrr]

mine did that when I ran no baro solenoid. On a decel if you go below 20in of vac the computer checks the baro real quick and if the line is hooked strait to the map then barometric pressure now equals 20 in of vac. Then when I tried going into boost it would hit overboost at 0 on the gauge and do what yours is doing. It also will do it if its in limp in.

[Aries_Turbo]

he still has the baro read.

Brian

[turbovanman²]

mine did that when I ran no baro solenoid. On a decel if you go below 20in of vac the computer checks the baro real quick and if the line is hooked strait to the map then barometric pressure now equals 20 in of vac. Then when I tried going into boost it would hit overboost at 0 on the gauge and do what yours is doing. It also will do it if its in limp in.

I have no baro on my SMEC and it runs fine.

[shackwrrr]

I have no baro on my SMEC and it runs fine.

must be a sbec thing

[turbovanman²]

must be a sbec thing

Could be,

[slasky]

he still has the baro read.

Brian

No I don't but I haven't had it for years.

[Pat]

Why would you not run the baro solenoid?