need help - 2G talon is lacking power

[boostedEG]

ok, so theres a long story behind this car, but the short version is that its a 95 talon TSI, and a 97 motor was just installed. i used a 1G cam angle sensor (CAS) to get past the problems i had with the differences between the 95/96 CAS and the 97+ CAS.

the problem is that it just lacks power. it makes boost (according to the stock gauge) but its still slow. its had this problem before the new motor was installed though, so i dont think it has anything to do with the motor or CAS change.

any ideas or common problems related to this?

i have a spare ECU, but its such a pain in the ass to change it on one of these that i didn't want to unless there was a pretty good chance it would fix my problem.

thanks

[ryanman]

Is the turbo in ok shape? Cam and ignition timing set right? Getting enough fuel? Fuel filter not clogged? Any CEL's? The "alignment ring" in between the exhaust manifold and turbo isn't sitting crooked is it? Seen that happen quite a few times and cause this same problem, if it's in there, take it out. Cat converter clogged?

[john]

Have you logged it?

[boostedEG]

Have you logged it?

no, i dont have the ability to do that

[boostedEG]

[QUOTE=ryanman;712928]
Is the turbo in ok shape? yes. i was told its a 16g when i bought the car, but i really cant tell the difference between 14b, small 16g, and big 16g, so i dont know.
Cam and ignition timing set right? the T-belt has not jumped a tooth, and from the factory the timing is not adjustable... with the 1G CAS i just installed there is some adjustablitity. however the motor has an aftermarket crank pulley with no timing marks.... but like i said its had this problem when it was 100% stock, so i doubt its related to that. i have the CAS set in the middle of its adjustability range.
Getting enough fuel? dont know...
Fuel filter not clogged? dont know.. will check/change
Any CEL's? yeah, the light came one about 15 minutes after i got it started, haven't had a chance to check the code yet, i plan to do it tonight.
The "alignment ring" in between the exhaust manifold and turbo isn't sitting crooked is it? Seen that happen quite a few times and cause this same problem, if it's in there, take it out. not sure on this one. i haven't had the turbo seperated from the manifold, but the previous owner of the car had this same issue with a stock turbo before he swapped on the supposed 16g
Cat converter clogged? its possible thats the first thing i'm gonna check.



thanks for everybody's help

[Minotaur]

Consistant acceleration? Choppy, occasional hiccups? No clutch? Can you feel boost engaging? Run different cold than hot? Massive blowby (do a leakdown test)? +everything Ryanman said.

gazillions of things it could be.

[boostedEG]

Consistant acceleration? Choppy, occasional hiccups? No clutch? Can you feel boost engaging? Run different cold than hot? Massive blowby (do a leakdown test)? +everything Ryanman said.

gazillions of things it could be.

smooth acceleration
what about the clutch? its still good
you can barely feel boost coming on, cause its still slow under boost. it is seeing about 10PSI
runs the same regurdless of temp
no blowby


also, its not a clogged exhaust, i took it off today and same shit. i will try a new fuel filter and check the fuel pressure... if its neither of those then i guess i will try my other ECU

[ryanman]

Check that alignment ring between the turbo and the exh. manifold. Maybe a forgotten rag stuffed into one of the IC pipes? Big boost leak?

[Minotaur]

Kinda just sounds like you have way too small of gears in it or something, if it's not mechanical. Does it take off in 2nd or 3rd?

Edit: I don't know if it's been re-greared, obviously, but if you don't know, maybe it used to be a high-rpm setup or something... I'm just using my kart experience to look at this.

[ryanman]

No, that wouldn't have happened.

[fusionsport]

boost leaks

the factory "gauge" is a guess based on airflow, and is not a reliable indication you are actually making boost. Also to check are:
MAF meter is plugged in and working
Fuel Pressure- at the rail, using the tool designed for the job
Plugs are correct and gapped to .028
Wires are in good shape

check these and get back to me

[boostedEG]

boost leaks

the factory "gauge" is a guess based on airflow, and is not a reliable indication you are actually making boost. Also to check are:
MAF meter is plugged in and working
Fuel Pressure- at the rail, using the tool designed for the job
Plugs are correct and gapped to .028
Wires are in good shape

check these and get back to me


i figured the factory gauge was inaccurate, as every factory boost gauge seems to be, but i had no clue it was basically a guess. i'll hook up a real boost gauge next time i get a chance to work on it.

MAF is plugged in. the one currently on the car came from the same car the new(er) motor did, and again that car ran just fine, so i doubt thats the issue, but i guess i could try a spare one just in case

what exactly is the "correct" tool for checking the fuel pressure? i have the snap-on fuel pressure tester

will double check the plugs, but again they were in this motor the whole time and it ran fine in the other car.

wires looks ok, not that okl, but i will double check the resistance in them.



one last question... how do i pull the code from the ECU? alldata says to cycle the ignition on-off-on-off-on and it will flash the code for me, but i can't get it to flash at all. and i don't have the right adapter for my scanner.

[drcustom]

AutoZone will pull the code for you, for free. All you have to do is ask.

Also, the turbos are easy to tell apart. The fastest ways are:
number of compressor blades
number cast and stamped on the compressor housing (the one that's like 10 digits and starts with 4)

[boostedEG]

autozone will not scan it, they only do OBD2, and i have an OBD2 scanner myself anyways.

by the way i finally got a boost gauge on it and it seems to only be making about 4 lbs of boost... so time to hunt down those boost leaks!!

thanks everyone.

[dsmkid]

throw a boost controller on it

[ryanman]

Why when it obviously has boost leaks, it won't do anything but cause problems.

[fusionsport]

i figured the factory gauge was inaccurate, as every factory boost gauge seems to be, but i had no clue it was basically a guess. i'll hook up a real boost gauge next time i get a chance to work on it.

MAF is plugged in. the one currently on the car came from the same car the new(er) motor did, and again that car ran just fine, so i doubt thats the issue, but i guess i could try a spare one just in case

what exactly is the "correct" tool for checking the fuel pressure? i have the snap-on fuel pressure tester

will double check the plugs, but again they were in this motor the whole time and it ran fine in the other car.

wires looks ok, not that okl, but i will double check the resistance in them.



one last question... how do i pull the code from the ECU? alldata says to cycle the ignition on-off-on-off-on and it will flash the code for me, but i can't get it to flash at all. and i don't have the right adapter for my scanner.

To check fuel pressure you need the fitting that adapts at the rail. I had to special order mine as they havent carried them on the truck for about 5 years. It takes a couple minutes to put on but its not really THAT big a deal.

If the plug wires even LOOK bad I would replace them, that is the number 2 reason there are drivability problems with these cars- Number 1 is boost leaks. Plugs are also always suspect and if you have run over-rich for any length of time they are useless and you might as well replace them. At about $2.50 each its just stupid not to. Also make sure they are gapped to .028, they do NOT come pre-gapped- ever.

Zto find the boost leaks you will need a boost leak tester and some soapy water. Typical problem areas are: TB shaft o-rings, BOV flange,BOV itself, Turbo outlet flange- especially if you have used silicone, TB inlet gasket- especially if you used silicone, injector O-rings, PCV hose, cracked couplers(yes, cracked- you wouldnt believe how many times I see that)etc.

If you like we are very familiar with all the DSm issues and can help you out with it, just give us a call at the shop to set something up.

EDIT- All 2G's are OBD2 and pretty much any OBD2 code reader will work. If your code reader wont work I KNOW mine works perfectly on 2G's. 1G's are OBD1 and require a Logger to check the trouble codes.

[Dsmboi50]

throw a boost controller on it

dont post useless crap you know nothing about k?