Car boggs during heavy acceleration, then runs fine?

[TooFastTooG]

Okay this is kind of a difficult problem to explain so bare with me here.

About 4 days ago I noticed that when I give it lots of gas it seems to hold back for about 3-5 seconds then returns to running fine. Now let me try to explain what i mean by "boggs".
The car will run perfectly fine but once I step on it it seems to loose lots of power and the most noticable thing is that my exhaust goes from a smooth tone to a kind of choppy pulsating noise, then it goes back to normal and the car runs fine. but it continues to do this when ever I give it some gas. My car will NOT do this during normal acceleration, only during wot or close to it.

The really weird part is some days its better then others, some days it will barley do it while days like today it was really bad. I just checked for boost leaks like a week and none was found, and my boost gauge will show normal boost while it does this(about 15 psi is what im running right now. Mods on my car include: K&N filter on pipe, manual mbc, dejon tool uicp, and 1st gen BOV, my car also has a 2.5 inch "axle back" exhaust that was on it when I bought it.

thanks for the help in advance!

 

[Byrd]

Hey man, i had this problem with my car about a month ago and have yet to experience it again (since i got dsmlink). Is the car warmed up? Mine would only fall on its face when it was cold outside and/or it wasn't to fully operating temp. And i think the stuttering or falling on it's face is from being way too rich. What are you using for tuning/logging?

 

[TooFastTooG]

Hey thanks for the quick reply, what weird about what you said is that about a month ago when it was like 2 degrees here it did it, and that was when it was cold, then it warmed up and then it was fine, but now it does it even when it is warmed up. And I currently dont have anything in terms of tuning/logging. That was coming next when I bolt up my 16g i have in my garage. Im still running mostly stock including the t-25.

 

[DECODER22]

hey toofast u got aim???

 

[drmcstroks]

check ## plugs and wires... they're usually at fault. if both those are ok then check ## TPS and coil pack. plugs and wires are cheaper so try those first. i was just having the exact same problem... new plugs and wires worked for me

 

[AWDPetmitsu]

check ## plugs and wires... they're usually at fault. if both those are ok then check ## TPS and coil pack. plugs and wires are cheaper so try those first. i was just having the exact same problem... new plugs and wires worked for me

Exactly what he said. Go with plugs and wires first and if that doesn't solve it, check the TPS.

 

[pinkandgeek]

I am also having this problem, I was thinking that it was the TPS, but is there a way to test it and test the coil pack before I go buy one?

NOTE: one difference is that mine will only do it immediately after turning a corner and opening the throttle fully. I have already changed my plugs and wires, so on to the TPS and coil.

 

[super97gst]

phantom knock. if you swap the plugs and wires and it still doesnt fix nething, then i would bet its phantom knock. when i bought my gst i had that problem. seems a lot dsms do. i was only able to correct it through dsmlink. BUT, i believe there might be another way to fix this problem. i had a long conversation about this same thing with a guy on here couple years ago. he said he had swapped out his oem lifters for a set of 3g lifters and it fixed the problem. if that does work it would definitly be cheaper than dsmlink. i'll see if i can find the thread about that when i had that problem and ill post it here.

 

[BlazeGT4]

Wasn't there a pseudo fix for phantom knock by way of placing an insulation washer between the knock sensor and the block? ie, something to reduce the vibration of an over sensitive sensor?

Maybe not such a good idea if your knock is actually exceeding a safe threshold.... Best to log it and see whats really going on. I was using a Turbo XS Tuner pro on my evo for a while. It comes with it's own knock sensor so you get a "second opinion," plus it allows you to actually HEAR what's going on.

But +1 on the plugs. Especially if you're running coppers. You might also do a pressure check on your wastegate actuator if see if it's not hanging open, as well any other sensitive vacuum lines (like the one near your FPR).

 

[spyderturbo007]

Wasn't there a pseudo fix for phantom knock by way of placing an insulation washer between the knock sensor and the block? ie, something to reduce the vibration of an over sensitive sensor?

Although there are "fixes" for phantom knock, you have to be really, really sure it's not real knock before you go messing with the knock sensor. We don't want to be blowing anything up.

 

[khartley]

I was about to post a new thread about this exact thing, but I figured I'd just jump in on this one instead.

My car does this bogging/hesitation thing at random, but always when I'm trying to boost...whether it be boosting during normal driving to get up a hill, or actually trying to go fast. Sometimes it feels as though I'm dragging an anchor.

I just did my final boost leak test tonight to be positive, but I have NO boost leaks at all. I have my stock boost controller on, stock FP, with my 510cc injectors and vr4 fuel pump. Is it possible I am too rich? I plan on getting DSMlink with my tax return money...
Also I have stock heat range plugs in right now, cause I had to replace them with stockers. Could that be a possible problem as well? I am running with 8mm plug wires, I don't think there is a problem with them.
I also have massive lifter tick. I may try and change them soon...

I thought possibly my fuel filter could be clogging and contributing to this problem, anyone else think thats possible?

 

[super97gst]

I was about to post a new thread about this exact thing, but I figured I'd just jump in on this one instead.

My car does this bogging/hesitation thing at random, but always when I'm trying to boost...whether it be boosting during normal driving to get up a hill, or actually trying to go fast. Sometimes it feels as though I'm dragging an anchor.

I just did my final boost leak test tonight to be positive, but I have NO boost leaks at all. I have my stock boost controller on, stock FP, with my 510cc injectors and vr4 fuel pump. Is it possible I am too rich?
I plan on getting DSMlink with my tax return money...
Also I have stock heat range plugs in right now, cause I had to replace them with stockers. Could that be a possible problem as well? I am running with 8mm plug wires, I don't think there is a problem with them.
I also have massive lifter tick. I may try and change them soon...

I thought possibly my fuel filter could be clogging and contributing to this problem, anyone else think thats possible?

the plugs are not causing the problem, and the massive lifter tick is more of a tell tell sign. running pig rich will not cause it, at least not exactly that. and the plugs wouldn't either, even if you had a plug totally fouled it would just miss badly. no, on the fuel filter idea as well. fuel filter restriction would bog you down to the point of killing the engine. from my experience the only thing that causes this exact problem is phantom knock.

running a log or having dsmlink of something similar is the only way your going to know for sure though. then you can tell if its real knock. the only feasable idea i know of for this problem is the 3g lifter swap. i think im fixing to try just that and see if it solves the problem, cause i do still get this problem from time to time.

 

[dsm4fun]

I am also having the same problem but with some differences in my 2g gst i have hard pipes bov and an injen intake. For instance on cold starts and just leaving for work with no warm up it just drags like im pullin another car behind me. Now for the sort of stuttering cutting out problem I never had this before my smog this year what happened is my car wouldn't pass so they welded on a new catalytic converter and it passed . So i started driving it again and noticed the cutting out problem but only at wot. Now ive tried the new plugs just for fun plus the car probably needed em but it didn't help so i got under the car at work on a lift and my catalytic converter is like 1.5in and im wondering if this is causing it? because when it cuts out it is more of like a sudden loss of maybe 10psi give or take or like an old v8 when they start loading up and then bam backfire from hell but the thing runs great after. So im not sure at all what it could be but it would be great if more people posted some helping thoughts and info because the first ones are helpful but im going to try the new exhaust because im getting my 3in turboback put on tommorow.

 

[mokstuning]

first thing to check is the pressure of the fuel pump ... that happens when gas pressure is not at its normal level .. plugs and hi tention wire . 2nd thing .. dont buy yet .. i you have spare try it . any wire will do as long as it fits .