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.

 

[juanpac0]

NGK Platinum plugs are what you're using I assume? Try NGK BPR6ES gapped @ .028".

 

[rarest_90_DsM]

What size injectors do you have? have you checked your ignition timing to see what its set at if it is advanced too much it might cause this problem. also the standard for a turbo dsm is the ngk bpr7es its a shade colder plug and will help with knock. it sounds like you may be hitting fuel cut (maf overrun) correct me if im wrong but ive never heard of someone hitting it at 11psi? but basically your flowing more air into the system then your maf can handle so it basically freaks and shuts down do a search on the forum and see what you can find for fuel cut! and check your base timing and cas

 

[dsmfa9nutter]

Your profile says you have a walbro 255 and in here you say you have a supra pump. Either way, you're running WAY too rich and you need an afpr. Going from stock to a 255 on my car bumped fuel pressure by 10psi and I had the exact same issue you are having now until I adjusted my afpr back to normal running pressure. Check your plugs, I'd bet money they're black as coal.

 

[habitatguy187]

Come on guys, "Feels like hitting a brick wall" Doesn't that mean something to you? BOOST LEAK TEST

Also from a quick search:

http://www.dsmtuners.com/forums/tun...y-if-hit-brick-wall.html?highlight=brick+wall

http://www.dsmtuners.com/forums/new...ing-brick-wall-help.html?highlight=brick+wall

http://www.dsmtuners.com/forums/tun...s-through-powerband.html?highlight=brick+wall

http://www.dsmtuners.com/forums/pro...eems-hit-brick-wall.html?highlight=brick+wall

http://www.dsmtuners.com/forums/pro...n-boosting-fuel-cut.html?highlight=brick+wall



EDIT: Plugs are fine, just make sure the gap is set right. Also my 14b turbo hits full boost around 2800rpms just for reference. This is ALMOST CERTAINLY a boost leak, but if it's not we'll help you out.

 

[habitatguy187]

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

What psi did you pressurize the system to? How long did it hold?

 

[insanedsm2403]

Thanks for all the responses.I don't have platinum plugs but ill try the one step colder plugs.the car we are reffering to is a 90 tsi awd and my other talon is the 93 tsi fwd in my profile.I'm defentely not hiting fuel cut.it sounds a little more like a rev limiter it just won't pull anymore.my 02 sensor reading v keeps flying up and down from like .0v to .85v,then.15v then back up.I don't know if that means anything but it looks wierd on the graph.I've adjusted my cas a few times today.I don't have a timing gun and can't find one to rent so today I tried putting it at many different spots and going for rides.the car felt different in power everytime but it still kept ''hitting the wall.''THIS SUCKS!its like no matter what I do it keeps doing this!

 

[insanedsm2403]

Also I have stock 2g injectors with stock 2g fpr.my mas signal never really gets near 1606hz as I can't get past 4200 rpm no matter what.and I did my boost leak teat at 20psi to be sure it would hold 15 which I want to run if I can ever get it to run right.

 

[habitatguy187]

Again,

What psi did you pressurize the system to? How long did it hold?

Another thing you want to check if you haven't is your ecu. My caps had leaked and it felt just like fuel cut, same symptoms and everything. Turn the boost up, hit the wall sooner, turn it down, hit it later. Turned out to be the ecu

 

[insanedsm2403]

My ecu has a rebuilt tag on it and I opened it up.no funny smells no burned spots,pretty clean actually.its funny you said that about boost because it seems if I set the car at full boost it will actually go for a little longer.usually it will keep pulling hard untill I hit fuel cut at about 18 or 20psi.still that wouldn't take me much over 4k

 

[insanedsm2403]

So far I have changed plugs,wires,coil pack,boost controller,tb,changed inj insulators,boost leak test,adjusted cas.I don't know what else.nothing is working

 

[rEclipserGST]

So far I have changed plugs,wires,coil pack,boost controller,tb,changed inj insulators,boost leak test,adjusted cas.I don't know what else.nothing is working

Compression test, Leak down test, BOOST leak test again. What fuel management do you have? I would recommend going with a 2g mas sensor. Alot of 1g's upgrade to this because the 1g maf maxes out. Just pick one up, swap it in.

 

[insanedsm2403]

I have stock engine management.will compression test tomorrow morning,but car has new hg and has plenty of power until I hit full boost,but I will do the test.and my mas signal never gets close to 1606hx on my logger.could I still be overrunning at 11 psi with less than 1606?if so I do have 2 2g mas laying around but won't I need a afc then?and thanks for all the suggestions I really appreciate it

 

[insanedsm2403]

Once again if anyone needs ANYTHING of my logs let me know all you need and ill post how my numbers came up.

 

[juanpac0]

The not wanting to pull anymore sounds just like what happened to me when my timing was off @ the CAS.

 

[insanedsm2403]

Really it would sputter and not go past 4k?because I'm so out of ideas.today I checked compression came out pretty decent.I have changed plugs,wires,coil pack,boost leak test,tb shaft seals,inj insulators,compression test,and nothing worked.about the timing though I tried moving it to a few different spots and the car would either feel faster or slower but I still always keep getting stuck at about 3,600rpm.if timimg it with a gun will stop this though I will go out and buy one asap

 

[Demon33]

So far I have changed plugs,wires,coil pack,boost controller,tb,changed inj insulators,boost leak test,adjusted cas.I don't know what else.nothing is working

Have you verified your base fuel pressure is set correctly (with vacuum removed from FPR) and verified that the pressure drops when vacuum is applied to the FPR and rises 1:1 with boost pressure?

Have you ruled out a dirty fuel filter or dirty, stuck or clogged or otherwise malfunctiong fuel injector? Are all injector electrical plugs securely fastened?

What condition is your fuel pump in? Is it getting enough voltage?

Does this problem happen only during boost (load) or can you duplicate by simply reving up the engine without actually driving the car?

 

[insanedsm2403]

Thanks very much for the replies.Well running with the vac plugged into the fpr I get 43 psi on my gauge ontop of filter.my injectors are fine because with my logger I can turn them off one by one and everyone makes a drastic idle change when turned off.I have my timing dead on 5 btc and still I have this damn problem.the car will rev in nuetral with no problems,I only went to 5500 because I'm not a big fan of free revving a motor.the car will go and pull hard with no misfire AT ALL until I get full boost.as soon as I get a full 11psi at about 3500 or whenever full boost kicks in it sputters and pops and throws knock.last night I took it on the highway and it seems the higher in gear I go the less I can go wot.its so bad in 5th that ill give it wot from a cruise and have to start backing off almost imediatley and it'll go.then a few secs later it will start doing it again and I have to keep on letting off the gas for it to go anywhere.ill be lucky if it'll pull at half throttle in 5th and it takes forever to get to 80.I tried to pass a grandma doing 70 on the highway and it took forever for me to pass with it trying to sputter and pop and then she floored it and flew by me anyway.I think i can hear a misfire on decceleration when not on the gas such as on a downshift.this is soooooo freaking retarded.I'm embarresed to own this car right now

 

[insanedsm2403]

By the way I have 2g inj with 2g fpr and supra fuel pump.my question is not will I run too rich or what not because I don't smell much fuel.my question is will this setup cause this sputter, popping, bucking?it feels like I hit a rev limiter that if I stay on will blow my motor.I have owned the car for about 3weeks now and have never once been able to go past 4000 rpm.it usaully cuts out around 3600to 3800

 

[Demon33]

Can you rev the engine freely past the rpm point in question while the car is parked? Does the problem occur while doing this?

It would be nice to know your AFR (air-fuel ratio) to see if you're running the proper amount of fuel at all times. Do you have a wideband O2 available or installed?

Again, you could have a clogged fuel filter that flows enough fuel during low engine load conditions but restricts fuel flow during high load (i.e. boost) conditions. If the filter is old or you don't know it's condition, you might think about replacing it. It's good preventive maintenance at the very least.

You might also have a bad MAS. When you go past a certain throttle position, the ECU no longer looks at the O2 sensor feedback to control fuel delivery. It calculates fuel requirements based on air flow, barometric pressure, air temperature, etc. These sensors are all located in the MAS.

Clean your air filter if it's really dirty too.

 

[JayRolla]

The pump is maybe overruning the stock FPR but at WOT it should not cause an issue. Only at cruise and idle. Its really hard to see what you are trying to say.

First you say its a brick wall. Now you say its a sputter and bucking? Which one is it. Brick wall would feel like the motor shut off which is fuel cut.

Bucking and sputtering is usually from a real rich or lean WOT condition or a bad spark.

To me it sounds like spark is getting blown out. What gap did you gap the plugs too?

 

[insanedsm2403]

Sorry if I mislead everyone by the title.its not a brick wall like my friends 7mgte supra.when it creeps boost and hits cutout you fly into the seat belt and don't want to drive the car for the rest of night.this is more of a wall in a sense that it won't pass 4k no matter what.it just sputters bucks, pops,starts knocking and won't go any higher.now my filter looks like it was changed still has nice white letters on it but I will change if I can't get around it.I changed my mas with the one the car originally came with,and still no cigar.has new k@n air filter.I have brand new advanced auto (I know!)spark plug wires with new ngk not fancy at all $2.00 a piece bpr6es I believe they are.i gapped them to .28.ill switch to a black top cas tomorrow see if that does it.I can't at this time upload a graph off my logger because my comp was stolen,but you must accept this ghetto version on the next post with any info I think valuable.any info I need to post let me know and ill do it asap!thanks for the help guys its nice to know someone out there can help.

 

[rbwtrans]

For a 1g the 2g FPR has too much fuel pressure. As you stated "43 psi". This is too much for a 1g. 1g's run 37.5 w/no vacuum. You're too rich. Either get a 1g fpr or an adjustable one. Set your fuel presure correctly and your problems will go away. The 2g injectors are the same as the 1g (except for the color) so your ecu can run them with no problems, but your ecu doesn't know what to do with so much fuel pressure. Check your adaptives. I bet they're maxed. Good luck.

 

[insanedsm2403]

Damn I've had a funny feeling about that 2g fpr from the start.I will change back to 1g in the morning.well took the car out for some wot runs and this was the longest one I could get.it got so bad I thought the motor was going to blow so I let off.I cpoied it off my palm pilot and its impossible to get consistent rpm points but I did the best I could so please don't bash it.
Rpm tima 02-r mafs injd
1562 20 .82 239.0 8.5
1687 21 .85 257.8 9.3
1718 20 .87 276.7 10.1
1781 20 .87 289.3 10.9
1843 20 .85 308.2 10.9
1968 21 .85 339.6 12.5
2093 20 .85 371.1 14.0
2156 21 .85 389.9 14.0
2218 21 .85 408.8 15.6
2343 20 .85 465.4 17.1
2406 19 .83 503.1 19.5
2531 16 .85 584.9 23.4
2656 15 .83 687.8 27.3
2812 15 .82 779.9 32.8
2875 14 .00 836.5 33.5
3031 16 .00 836.5 34.3
3156 16 .00 855.4 37.5
3000 15 .00 861.7 32.8
3093 18 .00 817.6 34.3
3156 19 .00 842.8 35.1
3281 18 .00 836.5 35.9
3406 19 .00 899.4 38.2
3468 19 .00 805.1 36.7
3718 20 .00 930.9 41.4

And that's all she had.full throttle 99.4 tps signal the entire time.this opened my eyes as to how little it really last at wot.I don't have a working rpm gauge so I kind of guesstimate and glance at my logger.hope somebody can find something with this info.

 

[habitatguy187]

For a 1g the 2g FPR has too much fuel pressure. As you stated "43 psi". This is too much for a 1g. 1g's run 37.5 w/no vacuum. You're too rich. Either get a 1g fpr or an adjustable one. Set your fuel presure correctly and your problems will go away. The 2g injectors are the same as the 1g (except for the color) so your ecu can run them with no problems, but your ecu doesn't know what to do with so much fuel pressure. Check your adaptives. I bet they're maxed. Good luck.

+1

I don't have a working rpm gauge so I kind of guesstimate and glance at my logger.hope somebody can find something with this info.

Unless it's something in the wiring the CAS reads the engine rpms, may also have a bad CAS along with the post above. Do you know for sure why the rpm gauge doesn't work?