91 TSi will not go above 2k when driving

[ZeroRain]

Hello friends! Well I've been doing a lot of work on the car lately. It was running great, sounded excellent and very fast. This was all before i installed my front mount. Before I did this I just had the turbo piped directly to the throttle body and it was perfect. I spent all evening get the new fmic installed and piped and clamped, the whole nine really. Everything looked great so i fired it up. Ran perfect at idle.I backed out of the garage no problem, took off no problem, hit 2k and sputters and shakes like no other. I assumed a pipe was loose. Pulled back in and couldn't find a problem anywhere so i rev her up and shes fine, go to power break and still fine. Pull back out and go to hit 2 again and same thing. I noticed while doing this that i loose all vac and hit a pound or two of boost. I'm new with forced induction so don't flame

Thank you

Zer

 

[phunny]

If you are POSITIVE it's not a boost leak, which if it idles perfect I would think you shouldnt have one, sounds like a fuel issue. If you have a failing fuel pump...etc you can free-rev all day but under a load you just fail.

 

[ZeroRain]

Boost leak is always possible but I double checked all my connections and ran everything over with a comb. I had a 2g rail on it with and adjustable reg and was showing 50 to 60 lbs at idle. I thought something might have been wrong with the reg so I swapped my stock back and issue continued. Maybe a fuel pump like mentioned or even a filter??

 

[phunny]

If everything was the same before the fmic install then I would replace the filter and hope for the best but it's more than likely a failing pump. Why is the fuel pressure so high at idle?

 

[dangler]

I would do a boost leak test, a visual inspection is not enough. I've had a couple fuel pumps go bad on me before but the car would only start to misfire up top, not fall flat on it's face. I have had boost leaks that cause the car to fall flat on it face at 3k RPM.

 

[ZeroRain]

Ill grab some supplies and make a tester and give that a shot. Now the pressure I never messed with it so thats why it was high I guess, what should it be set at for idle since its boost referenced anyway?

Zero

 

[phunny]

I would do a boost leak test, a visual inspection is not enough. I've had a couple fuel pumps go bad on me before but the car would only start to misfire up top, not fall flat on it's face. I have had boost leaks that cause the car to fall flat on it face at 3k RPM.

This is true to a point. The problem here is that it idles perfectly and he said he checked for boost leaks. And many many pumps fail in this exact same way.

 

[dangler]

1g base fuel pressure= 36.3psi.

 

[fourgsixthree33]

I would too say if it was a boost leak, it wouldn't idle properly. BUT, I would still try to do a BLT asap. Are you 100% positive that everything is hooked up correctly? Maybe some pics of your engine bay could let us see if anything was incorrect. If Everything checks out, I would start investigating into the fuel system.

 

[ZeroRain]

I solved the problem this afternoon! It turns out it was a boost leak. I pulled off all my silicone couplers and found one that was somewhat cracked. It wasnt huge but enough that as soon as vac would go to boost that it split open. Replaced as needed and whaalaa! She boosts like a champ and also has a kick as intercooler! Thanks again friends!

Zero