HELP.can't stop hitting BRICK WALL at full boost!

[insanedsm2403]

Het what's up everyone.I recently got a 90 tsi awd its all stock exept 3inch turbo back with external dump,supra fuel pump,2g injectors and regulator,autometer boost gauge,turbo xs boost control,and palm m130 datalogger.I can't upload any logs on here because my computer was stolen but I will gladly post any info neccesary to diagnose the problem just let me know what to put up.now I have my boost set at 10-11 psi and I have new plugs ngk bpr6es I believe,new wires,I changed the coil with a known good unit,I changed my mas as well.driving below full boost is nice and ill floor it and it starts to go,untill I hit full boost and at about 3700rpm it gets stuck for a second then starts missing and poping and sometimes will set of around 4-8 counts of knock if I try to stay on it.if I back off maybe 30% throttle it will start to go again untill about 4500 and gets stuck again.I'm out of ideas and would apprecite any help.posts will be responded to asap.thanks a lot


Ps.did boost leak test and found two at inj seal and tb shaft seal.both fixed yesterday.

 

[insanedsm2403]

Well I got the car with bent valves so idk if the rpm was working.I know for a fact it has a 92 cluster so I thought maybe since the car is a 90 it wouldn't work correctly,because my fuel gauge also does not work.I wired my cas to a 91-94 style using a article on this site.I will be swapping cas in about an hour and I will be hunting down that 1g fpr somewhere in my gargae also today.ill post back and let everyone know the outcome.....hopefully not the same.

 

[habitatguy187]

Did you check the ecu to make sure it's a 90 ecu? Also do you know whether it's for an auto or manual? They had different fuel injectors on 1G's. (auto had 390cc and manual had 450cc)

 

[insanedsm2403]

Back from doing some adjustments(like every morning)!I changed my cas to a blacktop and the car felt a tiny bit smoother but still same problem.I couldn't for the life of me find my 1g turbo fpr.instead I found what I believe is a 1g non turbo fpr.just being curious I slapped it on and with the vacuum on it read 40psi.better then the 2g but not much.I went for a ride and for the first time ever I was able to slowley give it gas till about 4k and then floor it and it spikes 4800 rpm!the car feels much better.I still have the problem but wow it feels way better now.can't wait to hunt down that 1g turbo fpr because I'm almost 100% positive the fpr is the problem.big thanks to RBWTRANS and DEMON33 for giving me the fpr and base pressure advice and thanks to everyone else for putting in time to try to help out a fellow dsmer.I will post again as soon as I put the proper fpr on and let you know the result.this time I'm pretty sure it'll be a success!

 

[insanedsm2403]

Oh and idk if its a stick or auto comp.is there anyway I can verify that because that would be bad if it was an auto.

 

[habitatguy187]

Oh and idk if its a stick or auto comp.is there anyway I can verify that because that would be bad if it was an auto.

ECU Part Numbers for DSMs

It's probably a manual ecu since pulling fuel with the fpr helped it out. I'd say you're good to go.

Also learn this website, it has lots of dsm info.

 

[dsmfa9nutter]

With A Supra Or 255 Pump, Whichever You Have, You Need An Afpr To Keep From Overrunning The Fpr And Causing The Exact Problems You Are Having. Please Learn To Read.

 

[habitatguy187]

1g fpr's are said to be able to take it, rarely do people with 1G's have problems with overrun on a 255, I overlooked that he had a supra pump, that and the fact that he has 2g/auto 1g fpr's aren't helping.

 

[dsmfa9nutter]

The guys that don't overrun using a 1g fpr and a 255 are the guys running much bigger injectors so it doesn't affect them. A lot of noobs don't understand just how much a 255 flows.

 

[insanedsm2403]

Well I can get a stock 1g fpr by tomorrow only its one hour away.now I'm kind of confused as to if it will work.some say it will overrun with my supra pump others say it won't.I don't have large cash to get a fancy $280 afpr but if I can't get away with the stock 1g what option do i have.its just my daily driver so I would really like to just use a stocko unit.if not possible does anyone know of an affordable afpr.I'm a little scared to get a cheap unit because I've been told I will regret using a cheap afpr in the long run.

 

[dsmfa9nutter]

The aeromotive is 150 brand new. I'm sure you can find a used one on ebay or in the classifieds here for less.

 

[JayRolla]

The aeromotive is 150 brand new. I'm sure you can find a used one on ebay or in the classifieds here for less.

The fpr being overrun does not effect WOT. He is having issues at WOT. If he was running pig rich at idle and cruise than yes he may need a FPR. Again the FPR being over run does not cause any issues at WOT!!!!

 

[insanedsm2403]

Question for JayRolla.are you saying that I don't have to change my fpr from 2g to get this problem solved or are you saying,get a 1g fpr to set the base pressure correct and then at wot it doesn't matter if I overrun it?

 

[habitatguy187]

The guys that don't overrun using a 1g fpr and a 255 are the guys running much bigger injectors so it doesn't affect them.

That statement makes no sense at all. Bigger injectors spray more fuel at the same pulse-width, so overrunning with bigger injectors would be even worse than overrunning stock injectors.

 

[slow4g6392tsi]

I ran a 255lhp hp on my car w/ stock fpr and it ran fine for over a year. Then I started having what seems like the same problem he is having so I put an aeromotive afpr kit on and set my fuel pressure to 38lbs w/ vacuum line off and hoped it would fix it, no luck. I tried a new maf, new plugs, new wires, etc. Still haven't figure it out.

 

[dsmfa9nutter]

The fpr being overrun does not effect WOT. He is having issues at WOT. If he was running pig rich at idle and cruise than yes he may need a FPR. Again the FPR being over run does not cause any issues at WOT!!!!

You do realize that fuel pump output is based off of voltage right? The voltage changes with rpms as the alternator output changes. There is more pump output at 8krpms than at idle.

OP, pull your plugs, I guarantee they're black. Go buy a new set and put them in, it will help for a little bit and then the exact same thing will happen. Then get an afpr, solve your issue, come back here and recommend me for a billion reputation points. Or keep dicking around with the same things over and over. It's your choice whether or not you want it fixed or if you want to suffer with the problem.

 

[insanedsm2403]

Honestly I don't care which one I use as long as this stupid problem stops.I want to try the stock unit first just to see if it pushes me in the right direction.you have to understand I have been going out and taking advice and buying new parts for it all to end up not solving this issue.I have put so much into this car that it should run like a beast but instead I end up with a f***ing rice can that can't even beat a stock crx.I hope this base pressure technique works.if it does I will end up getting a afpr in a little.when I sort of climb out of the hole this car is putting in my pocket.is It too much to ask of these cars just to be a freaking decently fast daily driver?

 

[dsmfa9nutter]

Mine is a daily driver, has yet to lose since I built it, and runs a 255hp with an aeromotive afpr.

 

[87Star4G64]

I'm not sure how much this will help but my 87' Quest when it was mostly stock except, turbo back 3" with no cats, and normal reliability upgrades for Quest's I would hit a spot where the car WOULD NOT go past about the same spot 4k it was right after changing a turbo and I was mindless and overlooked all my I/C piping and I had two loose hose clamps that I didn't think would of caused a problem, especially at 7lbs of boost but what do yea know I tightened them up and took her for a ride the car was completely different. So just go over all your hose clamps.
Maybe your I/C is corroding like my brother 1G I/C did/

 

[insanedsm2403]

@#$%

 

[insanedsm2403]

My boost leak test twice at 20psi would've revealed a loose clamp or what not.trust me guys if it was some loose bolts/clamps/hose/ I would've caught it long ago and this post would never have been started.I've been under the hood every single day since I got it about 3 weeks ago.sometimes I just stare under the hood,feel around at everything just to make sure its all in place.I've done that so many times I can't even count now.

 

[insanedsm2403]

Well put the 1g turbo fpr on and the fuel pressure was almost at 37.5 psi on my gauge.took the car for a ride and.................!!!!!!!!!!!!!!!!!!!!!!!!that's right,nothing.still same exact problem!and to make matters even better the cars slave cylinder decides to take a crap leaving me stranded an hour away.got car towed home and haven't even looked at it.will post again when I do some more work to it.

 

[habitatguy187]

I'd try to borrow a ecu from someone and see if that fixes it.

 

[dsmfa9nutter]

Have you tried an afpr yet?

 

[insanedsm2403]

One question on 2g injectors looking at the part that sprays out fuel,what should I see.4 tiny holes?mine are blacktop and the tips are green but it doesn't have the little holes,just one wide opening.

 

[habitatguy187]

Have you tried an afpr yet?

Sounds like it might be time.

One question on 2g injectors looking at the part that sprays out fuel,what should I see.4 tiny holes?mine are blacktop and the tips are green but it doesn't have the little holes,just one wide opening.

That's how they should look.