[SOLVED] Car won’t go past 80 MPH

L

Lui

Greenie N00B Member
Owned this car for 2 years I do all my own work on it. Car is stock with economy ots tune. Most recent maintenance I’ve done is clean and flow tested injectors from graveyard and over speed seals, ported and polished intake, cleaned valves, and spark plugs gapped to (.26). I do have HPFP internals. Car drives great until one day I notice I only boost 9-8psi WOT and car won’t let me pass 80mph. If leave my foot on the pedal it’ll just stay at 80 like a rev limiter but it stays at a fixed rpm. All my data seems okay. No codes. I’ve tested my HPFP, MAF, H02 sensor via alldata and tested okay. I’m at a lost at the moment and any feed back is helpful I have a clip of what I does if you need any more info from me please let me know. TIA
link: https://youtube.com/shorts/TXRRFfhNAtY?si=b6gAYrlkH6ReuZbG
 
have you done a boost leak test? what's your LTFT reading? hope that .26 is a typo for plug gap as spec is .026-.028" that decimal place is important otherwise you're gonna have a bad time. possible that the OEM ebcs has tanked as iirc that's spring pressure you're getting so I'd do a boost leak test and inspect the hoses going from the ebcs to turbo with age they'll crack then you won't get your boost.

*shudders at ?cobb ots tune* they're pretty terrible but if you've been running it for a while that isn't the focus here.
 
.026 gap is what I meant my bad and I did do a boost leak test everything past smoke only came out of the occ vent to atmosphere I took I also forgot to mention that check for turbo shaft play nothing out of the ordinary and I’ve heard the ebcs are trash on these cars but I tested by manually actuating it and blowing air to see if the plunger is moving and yes it is and not getting stuck but could be a different story when the car actuates it’s. I also bypassed the ebcs straight to the intake went on a light drive and obviously my boost pressures where how they were and exceeded it. I didnt want to go on a high way drive since I didn’t want to blow stuff up so never got up to 80mph. Would the ebcs cause it not to go past 80? I’ve tried reflashing the tune maybe thinking that was the issue but no luck. And my LTFT was at 2.36 when I topped at 80 mph but but idle sits at -1.56 while driving at 2.34
 
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Doesn't the economy tune turn the boost down and limit top speed?
 
I think that is what is causing the issues. PD-tuning.com and get a proper tune before that OTS map junk blows your engine.
 
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Had to time to work on the speed today and unmarried my AP and got factory tune back when on a test drive and is back to normal :) Also found my MAF O-ring was shot and replaced the PRV filter Waiting on my proper tune now and thanks to everyone that helped
 
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