Car lags BAD

[JBDdsmer610]

Ok my buddy just bought a 91 tsi fwd i test drove it for him the car is so much more responsive than my 91 gsx. The Tsi is bone stock it has no lag what so ever. I was just so baffled at the fact that the tsi had no lag compared to mine the rpms in the tsi jump right up when it spools. Now my 91 gsx has custo 3in all the way back 2g o2 housing and evo3 gt manifold, and stage 1 clutch and short shifter and MBC. My rpms dont jump like the tsi it takes about 10 to 15 sec just to get to 6000rpms. My knock sensor is totally cut and i have stock 14b i just cant figure out why the car is lagging so bad compresion is all good well decent and i have no boost leaks.

 

[blkwidow]

When was the last time you replaced your plugs or wires? Get a logger and do a compression check.

 

[JBDdsmer610]

I was planing on ordering a logger tonight and the wires are new plugs do need to be changed and the compresion is

125......115.........110.........120

 

[95blackGsTurbo]

He already did a compression test and check your timing as well as fixing your knock sensor. You need to have that hooked up or the computer goes into a default and you get asstastic timing causing slow rpm increase. And those compression numbers are a little low. Perfect is around 150. 110 is pretty low. Might wanna do a leakdown test.

 

[JBDdsmer610]

So i do need the knock sensor and the only other thing i need to do is check the timing could the knock sensor be causing my manifold and o2 housing to turn bright red.

 

[awdtalontsi1992]

Definately replace that knock sensor. When the computer doesn't see the knock sensor it goes into Limp Mode. As you would have no performance in bed in Limp mode...haha...your car will pull timing and richen the mixture (could be the cause of the glowing housing) and have poor performance. Those compression numbers seem low....were all the precedures followed completely? If they were then I would suggest you get that leak down test. Good luck.

 

[JBDdsmer610]

Before i did the compresion test i did a 3rd gear pull came back took the injector fuse out and disconected the wires and did the test but i need to do another one b/c the guage is from the 80's and its been dropped a few times

 

[awdtalontsi1992]

The gauge being bad is definately a possibility. I would buy or borrow a new one and recheck it.

 

[fwdturbobov1996]

How did the knock sensor get cut?

 

[JBDdsmer610]

The moron who had the car before me cut it and the car was A/T then now its 5 speed he knew nothing about the car

 

[No_Skillz]

... and i have no boost leaks.

It's pretty arrogant to claim that you have no leaks, since first of all having absolutely no leaks is impossible. Have you done the proper test? How much pressure are you holding and for how long?

It took me about a week of testing, teflon taping, clamp tightening, gasket sealing, and retesting to get my intake system where I was happy with it.

Additionally: You should check the status of your 14b. Make sure it's in good working order. Just off the top of my head, check for shaft play, bent fins, wastegate functionality. Also check to see if you have any pre-turbo exhaust leaks.

 

[JBDdsmer610]

Ok so i put my new knock sensor in today i see a big diff in power but the lag is still there. There is like no shaft play in my 14b no bent fins i just dont know what to check now im going to do a boost leak test tomorrow try and fix some other things

 

[No_Skillz]

i just dont know what to check now

How about:

... wastegate functionality... any pre-turbo exhaust leaks.

 

[Stainbox12]

Dude. Borrow another compression tool. Your numbers are very low. A stock 1st gen should have 165 in a healthy engine, maybe 150 with use but still healthy. The service manual says, that the service limit is 120 with a 14 PSI of difference maximum between cylinders. You are far away from spec in both ways. I would say that your engine doesn't have enough compression, Maybe bad rings, or even pistons at some point. If the tool is bad get another one, do a wet test, and if numbers go up. Get ready for a rebuild.

 

[Jeff822]

Dude. Borrow another compression tool. Your numbers are very low. A stock 1st gen should have 165 in a healthy engine, maybe 150 with use but still healthy. The service manual says, that the service limit is 120 with a 14 PSI of difference maximum between cylinders. You are far away from spec in both ways. I would say that your engine doesn't have enough compression, Maybe bad rings, or even pistons at some point. If the tool is bad get another one, do a wet test, and if numbers go up. Get ready for a rebuild.

My car has 90 compression and the test was done on 2 different testers and 1 test was done by a shop, i run 15 psi daily and my car still pulls hard. We did a boost leak test on his car and there were no leaks besides the turbo xs bov which he now swapped out for a crushed 1g. Btw, ive been driving my car with the compression this low for the past 6 months at least 75 miles each day.

 

[No_Skillz]

My car has 90 compression and the test was done on 2 different testers and 1 test was done by a shop, i run 15 psi daily and my car still pulls hard. We did a boost leak test on his car and there were no leaks besides the turbo xs bov which he now swapped out for a crushed 1g. Btw, ive been driving my car with the compression this low for the past 6 months at least 75 miles each day.

You must have 007 style smoke screen behind you. Good for cops.
Drive another car with the same mods and good compression and report back.

 

[Stainbox12]

My car has 90 compression and the test was done on 2 different testers and 1 test was done by a shop, i run 15 psi daily and my car still pulls hard. We did a boost leak test on his car and there were no leaks besides the turbo xs bov which he now swapped out for a crushed 1g. Btw, ive been driving my car with the compression this low for the past 6 months at least 75 miles each day.

That doesnt mean its correct. Compression numbers may vary a lot. And theres a lot of factors that may cause it, its not necessarly the rings or pistons, it could be valves, and some other things. Not every engine reacts the same way with low compression numbers. You can drive a car for a while with low compression, but the performance would not be as expected compared to a healthy engine.

 

[Jeff822]

You must have 007 style smoke screen behind you. Good for cops.
Drive another car with the same mods and good compression and report back.

My car doesnt smoke, just a little bit after idle from the valve seals.

 

[James Bondage]

I had the very same problem. I checked my base timing and it was set to 0. I was like wtf? I put it back to the stock 5 btc and the car came alive. When I launch now I get a nice little spin and chirp from the tires.

I also wanted to know of your having boost lag issues as well?

 

[JayRolla]

Damn someone must have pulled the timing to add lots of boost or someone was really stupid.

 

[James Bondage]

Damn someone must have pulled the timing to add lots of boost or someone was really stupid.

Someone was really stupid! Since I have rescued the car in March all I have done is maintenance work.

The good thing is my compression numbers are 170 across the board. It's a 92 6/4 bolt.

 

[JBDdsmer610]

So what your saying is check my base timing if its at 0 go to 5 btc. and yes i do have boost lag issues

 

[James Bondage]

So what your saying is check my base timing if its at 0 go to 5 btc. and yes i do have boost lag issues

Yes make sure your base timing is set to 5 degrees btc. I also had boost lag issues. I did a boost leak test and fixed one small leak. Still I had lag issues. I took off the wasegate and found I had a bent actuator arm.

Once I fixed those issues the car runs like a dream.

 

[JayRolla]

Could also be a bad knock sensor. Do you have a logger?

 

[Jeff822]

Could also be a bad knock sensor. Do you have a logger?

His knock sensor was cut and he just put a new one in the other day.