car building boost, but no power

[super97gst]

my gst has been having this problem since i bought it. it quit for about 6 months though and now its doing it again. i have tried everything i can think of to remedy this problem and searched all over this forum to no avail. heres what its doing: sometimes when i take off in 1st, not running it hard really either. the car will build boost just like normal. jumps right on up to 17 or 18psi, but the car just barely moves. and im not talking bout a clutch slipping either. the car mostly does this when i take off from a dead stop in 1st gear. it just feels very sluggish when it does this, thats the only way i know to explain it.

well thats all i can think of right now about the problem. if anyone has any ideas i would really appreciate ur input. thanks

 

[Clipse]

What kind of timing advance are you getting?

Does it feel like it's holding back if you do a 2nd or 3rd gear pull?

 

[Crawl]

I have a 95 gsx, ive owned for about 5 months, and The same thing has happened to me, Ill go to accelerate hard and boost will build but The car just chugs, I have to let off the gas and push back in to get it to start haulin again, its almost like its getting too much gas or something

 

[super97gst]

What kind of timing advance are you getting?

Does it feel like it's holding back if you do a 2nd or 3rd gear pull?

every once in a while it will hold back on a 2nd or 3rd gear pull. mostly 1st gear pulls. could a boost leak cause this?? im not a newb by any means but i just cant figure this problem out.

 

[Crawl]

I am fairly new to DSM , but for me it mostly happens in 2nd, though it has happened in 1st and 3rd as well

 

[2gForMe]

same thing happens to me, i dunno what it is.

 

[oldman]

If your car sputters when this happen do a boost leak test and check plugs and wires. If it doesn't, do a compression test and and check timing marks.

 

[VBGSX]

You say sometimes.
Tell us a little more about that.
Is this after the car has been sitting for a while?
Is this after you've been driving for a while and the engine is fully warmed up?
Etc.

Like oldman posted. Boost leak check. How old are your wires(and brand), what plugs do you have? How old are they? What are they gapped at? What do they look like(black with lots of carbon buildup, etc)?

I'll tell you another possibility.
Does it usually do it when the RPM's are fairly low?
When you let off and get right back on it, does it usually drive fine? Usually better if you do it (let off and get back on it) while the RPM's are above 3000 or more?
If so I would bet 10 to 1 you're having phantom knock problems and the timing is being pulled. Hear any lifter tick?
Mine use to do that. I use DSM link so as soon as the phantom knock would spike way up, my engine light would flash(Will do this with dsm link for knock above 5) and my knock meter(used the factory boost guage for this/with DSM link programed to do it) would spike.
The car fell on it's face. This usually happed around 2500-3500 RPM. As soon as you let off and gave it gas again, most of the time(not always) it would be fine.
My phantom knock ended up being the shitty lifters.
This is completely gone now with my 3rd Gen lifters.

If any of you have a way to log your timing(DSM link, logger, etc), log it and see if your timing is being pulled. If so, whawla....probably phantom knock

Thats a good start
Good luck

 

[Crawl]

hmm that sounds exactly like what happens, its low RPM and if i let off and back on its usually fine. Its *usually* when the car is colder (ie: let the car run for 2-3 minutes then go driving, about 2-5 minutes down the road ill stomp on it and you can hear the air comming in , boost builds, but Im barely moving)

 

[DSMTalonAWD51]

90%chance boost leak. Rev to redline first under boost, then slowly under no boost and listen for sputtering.

if its only under boost - boost leak
if it does it under no boost - plugs/wires

 

[Crawl]

Well My boost gauge and MBC come this week so i can actually see a little more of whats going on, I have brand new plugs, wires are close to new though I could try replacing them anyway. i have the stock BOV and i hear thats a pretty common culprit in a 2g, that is going to be one of my next purchases. I have no plans of turning up the boost past stock at this point anyway, but Ill do it just for the sake of the stock one being a POS.

 

[VBGSX]

Well My boost gauge and MBC come this week so i can actually see a little more of whats going on, I have brand new plugs, wires are close to new though I could try replacing them anyway. i have the stock BOV and i hear thats a pretty common culprit in a 2g, that is going to be one of my next purchases. I have no plans of turning up the boost past stock at this point anyway, but Ill do it just for the sake of the stock one being a POS.

It is very common to have boost leaks. Even after fixing them, you'll find new ones over time. That's why you do boost leak checks every once in a while.
Definitely get your boost guage installed. That will give you a reference to look at.
Then make this boost leak tester:
http://www.vfaq.com/mods/ICtester.html
I'll bet you find some but that may still not be your problem.

It sounds exactly like what I was going through with phantom knock.
A boost leak doesn't care if you let off the gas and get back on it. It would still be there and act the same. Boost leak doesn't nesessarily care if the car is cold or not.

Good luck and let us know how your boost leak test goes.
Hopefully thats it.

I'd still like to know what plugs you're using.

 

[Crawl]

right now i have the NGK 7ES but im going back to the 6ES , alreayd ordered them and they come soon. I also am getting a new port and polished head with a brand new valvetrain so if it is phantom knock that should take care of it.

 

[super97gst]

You say sometimes.
Tell us a little more about that.
Is this after the car has been sitting for a while?
Is this after you've been driving for a while and the engine is fully warmed up?
Etc.

Like oldman posted. Boost leak check. How old are your wires(and brand), what plugs do you have? How old are they? What are they gapped at? What do they look like(black with lots of carbon buildup, etc)?

I'll tell you another possibility.
Does it usually do it when the RPM's are fairly low?
When you let off and get right back on it, does it usually drive fine? Usually better if you do it (let off and get back on it) while the RPM's are above 3000 or more?
If so I would bet 10 to 1 you're having phantom knock problems and the timing is being pulled. Hear any lifter tick?
Mine use to do that. I use DSM link so as soon as the phantom knock would spike way up, my engine light would flash(Will do this with dsm link for knock above 5) and my knock meter(used the factory boost guage for this/with DSM link programed to do it) would spike.
The car fell on it's face. This usually happed around 2500-3500 RPM. As soon as you let off and gave it gas again, most of the time(not always) it would be fine.
My phantom knock ended up being the shitty lifters.
This is completely gone now with my 3rd Gen lifters.

If any of you have a way to log your timing(DSM link, logger, etc), log it and see if your timing is being pulled. If so, whawla....probably phantom knock

Thats a good start
Good luck

ive already done a boost leak check. throttle body seals were leaking, replaced them. im running ngk wires, about 3k miles on them. ngk bpr6es plugs, just swapped em in last week, gapped to .028. one was totally fouled. thats the reason i changed em.

if i get on it and get right back off then on it again it does do a lot better. and yes i have logging capabilities, dsmlink, i just havent installed it yet. its sitting in my shop. most is happening at low rpms just like u said urs did.

also im getting lots of lifter tick. whether the motor is cold or warmed up. i guess ill install my dsmlink this weekend and see if i can get a reading on phantom knock. its sounding more and more like im getting timing pulled all the time.

 

[2GeNTSi]

Bah I'm in the same boat as super97gst...been having this problem ever since I bought the car. Same building boost but doesn't feel like anything at all once it's spooled up, look at my modlist and I can tell you I barely felt a difference from any of the mods.

I've replaced plugs, wires, fuel filter, pcv valve, timing belt just done about 1k ago, and I just slapped on the 14B w/ a new o2 sensor from Denso (install kit from SBR) with still not much of a difference.

I have a logger, today I went to my friends house and had him ride with my while he paid attention to the pda...he didn't log it (don't know why) but he noticed at first at WOT it would only be at 8 degrees advanced and I guess my o2 was above 1v (rich?). But anyways they're are thinking maybe it's the knock sensor however I can't find a test in the Haynes manual. That and I'm going to make a boost leak tester and see if I can find anything, I think it might be leaking at the j-pipe a bit but I still think it wouldn't make THAT much of a difference.

 

[VBGSX]

ive already done a boost leak check. throttle body seals were leaking, replaced them. im running ngk wires, about 3k miles on them. ngk bpr6es plugs, just swapped em in last week, gapped to .028. one was totally fouled. thats the reason i changed em.

if i get on it and get right back off then on it again it does do a lot better. and yes i have logging capabilities, dsmlink, i just havent installed it yet. its sitting in my shop. most is happening at low rpms just like u said urs did.

also im getting lots of lifter tick. whether the motor is cold or warmed up. i guess ill install my dsmlink this weekend and see if i can get a reading on phantom knock. its sounding more and more like im getting timing pulled all the time.

I'd almost bet it's going to be the phantom knock I told you about earlier, probably caused by your lifters.
The easiest way for you to determine that is to go out and install your link...hahahaha
It should already come set up so when you get 5 and above knock, your check engine light will come on. What you can also do is go into misc. and change your factory boost guage to read knock. This way you'll see it even if it's below 5.
I'll bet that you'll get the check engine light to come on solid and the guage will spike to the top when you have the problem. If it does, problem solved. It could be real knock though, but more likely phantom.

Since you're having a lot of lifter tick, that leads me even more to the above. I would definitely spend the $138 or so and get the 3rd gen lifters. They're not to bad to put in.

I hope it works out for you.
Definitely let me know.

 

[VBGSX]

Bah I'm in the same boat as super97gst...been having this problem ever since I bought the car. Same building boost but doesn't feel like anything at all once it's spooled up, look at my modlist and I can tell you I barely felt a difference from any of the mods.

I've replaced plugs, wires, fuel filter, pcv valve, timing belt just done about 1k ago, and I just slapped on the 14B w/ a new o2 sensor from Denso (install kit from SBR) with still not much of a difference.

I have a logger, today I went to my friends house and had him ride with my while he paid attention to the pda...he didn't log it (don't know why) but he noticed at first at WOT it would only be at 8 degrees advanced and I guess my o2 was above 1v (rich?). But anyways they're are thinking maybe it's the knock sensor however I can't find a test in the Haynes manual. That and I'm going to make a boost leak tester and see if I can find anything, I think it might be leaking at the j-pipe a bit but I still think it wouldn't make THAT much of a difference.

With your case I would start from scratch.
Start with a boost leak check. and fix every leak no matter how small. Don't forget to get a spray bottle with dish soap and water. Spray everything(injectors seals, vacuum hoses, IC pipes, BOV, turbo compressor housing, TB, etc).

You're giving us limited info but 8 degrees timing peak is obviously a problem. You're not getting full timing advance.
Being rich could possibly indicate a boost leak. Think about it this way. Your car thinks "X" amount of air is being forced into the engine and adds fuel. Since you have a huge leak, "X' amount of air is less because it's leaking out but the computer still adds all that fuel. So now you have a richer condition than you should.

If you are having the same symptoms as I described above then it could be the same problem. Like I said though. Start with the most common and simple thing first....Boost leak test. Then we can go from there.

Good luck

 

[2GeNTSi]

Yeah I didn't feel too confident about the j-pipe when I got it on, need to find a shorter bolt for it. Anyways I will do the boost leak test sometime this week and afterwards I'll do a log.

Oh yeah about the lifter tick, I don't get much of it, only during winter mornings I would. But however one of my injectors tick randomly off and on pretty loud so possibly that.

 

[2gForMe]

alright this was only happening when my lifter tick was reallly bad.
i replaced my lifters and got the tick totally gone, and it hasnt done it since.
i go with the phantom kock being the issue.
get the lifter tick taken care of and it will prolly take care of it.

 

[super97gst]

i appreciate ur help vbgsx ill install the "link" and new 3rd gen lifters sometime this week, ill let u know what happens.

 

[VBGSX]

Any time.
Hopefully this will take care of it for you.
If for some reason there is still something wrong, getting a good log will definitely point us in the right direction.
We'll get you up and running right

 

[bboypuertoroc]

Good thing... I was just about to post about this problem. Good info and I'll be doing this (3G lifter swap) in the near future. Would this issue affect HP/TQ numbers? Just wondering... I put down 202HP/219TQ and thought it was a little low. Peace

 

[Nanan]

This is the exact same thing my car was doing last year. It seemed to happen when the car was cold and would go away when it got warm. I decided to run logs for a few days to see what was up and I noticed that my knock count was going through the roof in the 2500-3500 rpm range yet my boost was only in the 5 psi range.

I replaced my knock sensor and the problem became more rare but it still happened everyonce in a while. I continued to run logs and I noticed somehting odd when I would hit this brickwall boost issue, the boost pressure would quickly fluctuate from 0 to 5 psi quickly at the 2800-3100 rpm range. I looked up this problem on a few different boards and it turns out that there is something called BCS flicker where the ECU doesnt know if it should hold boost or not so it rapidly opens and closes the BCS. When I upgraded to a MBC the problem became even more rare, only a once a month occurance. When it did come up it was again high knock counts at the 3kish range, I guess that the problem was phantom knock hiding among alot of other problems. Once I get my DSMlink I will just disable the knock sensor below 3.5k rpm like alot of others have to cure this problem.

 

[2GeNTSi]

I'm going to do a 2nd gear log today, I tightened down the allen head bolts on the j-pipe as much as I could so maybe the leak won't be there (if I had one). Also one thing, I think maybe my plugs got fouled after the swap, I just replaced them earlier this year and I left the gap as it was (.030). According to my gauge, I'm only boosting 14psi so I shouldn't have any problem with that gap.

Well later on I'll post my results from the log.

*EDIT* Actually did a log right after I posted...it's from 2nd gear around 2-3k to 3rd gear about 6k. Wasn't going WOT until about 4k (forgot to choose TPS).

RPM Timing o2
2664 25 .32
2972 25 .74
3360 15 .96
3900 8 .98
4500 1 .98
5072 8 1.00
5612 10 1.00
6084 11 1.00
6484 15 1.00
6880 16 1.00

6632 17 1.00
4940 38 .96
5104 9 .98
5360 10 .98
5604 11 .98
5816 10.98
6064 11 .96
6252 13 .96

So it looks like timing gets pulled back from about 3-5k and in 3rd gear it fluctuates so I'm not sure what's going on there. Also looks like I'm running a bit rich in 2nd gear, but correct me if I'm wrong because I'm still very new to logging.

 

[VBGSX]

This is the exact same thing my car was doing last year. It seemed to happen when the car was cold and would go away when it got warm. I decided to run logs for a few days to see what was up and I noticed that my knock count was going through the roof in the 2500-3500 rpm range yet my boost was only in the 5 psi range..

hahahaha Yep that's it! Almost identicle to what I use to deal with

I replaced my knock sensor and the problem became more rare but it still happened everyonce in a while. I continued to run logs and I noticed somehting odd when I would hit this brickwall boost issue, the boost pressure would quickly fluctuate from 0 to 5 psi quickly at the 2800-3100 rpm range. I looked up this problem on a few different boards and it turns out that there is something called BCS flicker where the ECU doesnt know if it should hold boost or not so it rapidly opens and closes the BCS. When I upgraded to a MBC the problem became even more rare, only a once a month occurance. When it did come up it was again high knock counts at the 3kish range, I guess that the problem was phantom knock hiding among alot of other problems. Once I get my DSMlink I will just disable the knock sensor below 3.5k rpm like alot of others have to cure this problem.

A few extra things about your post.
Good info
I also first tried the knock sensor with no avail.
Timing can have a significant affect on spool up/boost

Disabling the knock sensor below 3.5k RPM is not a "cure".
1. It will keep the ecu from pulling timing because it won't look for knock under 3.5k RPM. That knock is still there though.
2. What if the ECU is still seeing it after 3.5k RPM? Are you going to keep raising the RPM where the ECU starts looking for knock? Yes I know most of the time the Phantom knock is below 4k RPM
3. What happens if for some reason it's real knock but you've raised the point at which the ECU starts looking for it. Now you have real knock below where it starts looking for it......Can you say bad problems.
4. The old style lifters get worse over time.

All you're doing is hiding a issue/problem that is still there. The best thing to do is find the problem and just fix it. If it's the lifters, they're not expensive or hard to install. Even without significant tick, it's not a bad idea to go ahead and swap them anyway. Just one less problem down the road.

I understand that you've tried to fix the problem by replacing parts. Like I said, that's the best way. I'm not coming down on you, I just don't want someone to think they can just change the ECU and the problem will just go away. It's still there and could/will get worse.

I also run DSMlink. My opinion is to change the ecu setting only after everything else has been exhausted and you know it's not real knock(Those with DSM link will know how to check this).

Hopefully all this great info will help others to narrow down their issues and help fix them.