car will not rev past 1700 rpm

[1g-90-newbie]

I NEED HELP ASAP!!!!!!! i recently picked up a 90 eagle talon tsi and it was running good when i first got it home it was reving up fine and boosting great but now from a cold start it will halfway rev up and once it gets warm it will only rev up to 1700 rpm and bounce back even when i hold throttle steady at 3/4 it just goes up and down from the 1700 rpm......and its a consistent rev every time. please help its my only ride to work!!!

these are the mods it currently has: 2g MAF , manual boost controller running 14 psi, denso 650 cc injectors, walbro 255 fuel pump, front mount intercooler, aftermarket blow-off valve, stage 3 clutch, safc ll air controller, lsd rear diff

 

[ninjadave]

Does it have an afpr on it? With those injectors and that 255 your fuel pressure is too high you need a way to adjust it. Plus you shouldn't be trying to rev a cold motor in the first place... But doing a boost leak test might also help along with routine maintenance plugs, wires, fluids, belts etc.

 

[1g-90-newbie]

im not reving high when cold just like 2-3k. and im new to the turbo scene so im kinda starting from scratch... it does not have a fuel regulator on it. i can probably pick one up tomorrow but would that stop it from revving past 1700 rpm? and when car is idling and i unplug the 2G MAF nothing changes.....

 

[Boostdriven]

I'm leaning towards MAF sensor issues, check to make sure that its still plugged in.

Never mind just see that you already tried that. Is there a chance that the wire connection is bad from a 2G MAF plug to the 1G harness? check that out just in case. If it ran fine before and then all of a sudden did this then it can't be the fact that you don't have a FPR but you should get one anyways. Also check to make sure that the intake pipe is tight on the turbo.

Defiantly do a boost leak test.

 

[1g-90-newbie]

yes it is plugged in but i think something wrong with it like i said before when engine is running and i unplug it nothing changes......????? would the MAF stop the car from revving up???

 

[YzRacer119]

Does it have a check engine light? If so diagnosing that will solve your problem and there is plenty of info on how to on this site.

If not that sucks. Probably your maf or just as likely it could be your ecu. You should remove the ecu, look at the board and check for leaky caps or burn marks. If there is any I'd replace it or have it repaired.

What your describing is EXACTLY what happened with my first DSM (a 90' laser turbo). Drove it home fine upon purchase, next day was doing the same thing your describing.

 

[1g-90-newbie]

i have a chipped ecu that came with car can i just swap it in or will that change everything??? what model car can i find another 2g maf to replace mine?

 

[YzRacer119]

Well if they messed up the chip and your rev limiter is set at 1700 rpm. But unless whoever burnt the chip is a complete asshat I doubt it.

If the ecu was bad you would have to get a "eprom" ecu and swap your chip to it. Unless your chip is bad then you would need to replace that and have it burned for your cars needs. Sadly the only way I know to find out is to replace the ecu and if that doesn't fix it then you know its the chip. Or it could be the maf. Unless you have a cel to tell you what's wrong your just going to have to Chase the problem down.

You can get the 2g maf from 95 and up eclipse and talons with turbocharged engines.

Sure you don't just have a blown coupler? Do a boost leak test but it'd have to be a huge leak to no rev over 1700

 

[1g-90-newbie]

ok thanks!!! but i meant that my car has a stock ecu in it now but i have a chipped ecu he gave me with car.... can i just swap them out???

sorry guys i forgot to mention that my alternator was overcharging (16.5-17 volts) if that makes a difference on solution??????

i finally had my car running today and now its flooding itself with fuel so i guess i need to put a fuel regulator on it.. can i put one inline before the factory regulator? and i tried swapping in my chipped ecu and it would not let my fuel pump kick on??????????????