Valet mode question

[LelandLs6]

Sorry if this is posted in the wrong place... Anyways

I've been having problems with my gn just backfiring like crazy at anything past 1/4 and just feels way too sluggish from what it used to be before I parked it... When I try and drive it I can barely get to 40 mph as it's just backfiring too much and won't rev out through the gear.

I don't have a full history on the car as we have had it 10+ years and the previous owner had tons of work done to it at connelys's in Houston tx

I've ruled out the maf sensor, cam sensor, crank sensor, injectors, fuel pump, compression, fuel filter, and the turbo does spin freely with almost no play...

Now sorry about the rambling but my question is if it is stuck in a valet mode, will disconnecting the ecu from the harness or disconnecting the chip for like ten mins then plugging it back in take it out of valet mode?

As stated I don't have full history, is has the factory alarm with the key code to start (yes I'm putting in the right code! Lol) and the chip is a mag4 from connelys's

Thanks for any help!

Leland

 

[TurboTdr3.8]

I would check for a flat camshaft lobe at this point .

 

[X Ray]

Does it have a wideband O2 ...if so it may need to recalibrated.

 

[Jerryl]

Location?

 

[LelandLs6]

Location is San Antonio

No wideband

And haven't had the time yet to pull valve covers off yet to make sure all rockers are moving evenly but that's my next move

Idk if it helps figure this out or not but in neutral I can rev it out all day long and it won't sputter or anything like it does when I try and drive..

 

[Jerryl]

Location is San Antonio

No wideband
And haven't had the time yet to pull valve covers off yet to make sure all rockers are moving evenly but that's my next move
Idk if it helps figure this out or not but in neutral I can rev it out all day long and it won't sputter or anything like it does when I try and drive..

Does not sound like valet to me. On my set-up, valet won't backfire. It simply just falls on its face when throttle is >XX%.
Worked on a similar issue for 2 years as it was sporadic.
Backfire through intake or exh.? What are the O2's when it backfires?

 

[LelandLs6]

It doesn't have a scan master yet so no readings which I know is just making this 100x's harder to figure out but it's back firing through exhaust always at same throttle level... You think could be throttle sensor??

 

[Jerryl]

It doesn't have a scan master yet so no readings which I know is just making this 100x's harder to figure out but it's back firing through exhaust always at same throttle level... You think could be throttle sensor??

Is that at a certain throttle position, regardless of RPM/Boost?

 

[LelandLs6]

Yes anything past 1/4 throttle is just worthless on it

 

[Jerryl]

Put a VOM on the tips and look for a flat spot. Voltage should rise smoothly and evenly. KOEOno throttle should be 0.4-0.44V as a guide.

 

[LelandLs6]

So with a vom I tap into the wires and with the koeoff moving the throttle plate should give smooth even readings and closed throttle should be .4-.44 correct?

 

[Jerryl]

Yes. The supplied voltage week/sb very close to 5V. Probably more like 4.999V

 

[LelandLs6]

Ok I'll give it a go and see what results I get

 

[Jerryl]

Yeah, I would start there. Could also be a MAF, chip/injector, ground, voltage, fp, etc.
If you plan to keep the car, get a scanmaster.

 

[LelandLs6]

Thank you for all the replies guys! After fixing my vac/boost gauge I found the problem to be ignition wise and it is now fixed!!! \m/