02 LSE SST Problem

[Pete02LSE]

I posted this in a different way a really long time ago and now that it seems more consistent, I thought I'd repost with additional information.

We have an 02 LSE and I have done some basic mods to it (exhaust from the cats back and gutted the air box). Before I modded it, it would occasionally stumble from a dead stop when in D5 and cold. Once warm, no problems at all.

Now, in D5, it will stumble from a dead stop pretty much anytime. In SST mode, if I drop the hammer, it will drop into first and just bog. And by bog I mean hit a brick wall. It's like I hit the brakes. If I back out of the throttle, it will stop bogginig and eventually get under way.

This sounds like a first gear problem to me and I have read posts on here regarding valve bodies and servo problems. I seem to remember reading one article on a computer related problem.

Question...Does anyone know if there are any TSBs or recalls for this? I searched and came up empty handed.

Thanks in advance.

-Pete
02LSE

 

[beaups]

sounds more like a fuel delivery or ignition problem. are you sure you turned off traction control? sounds almost like fuel cut.

 

[2002_LS_V8]

yea maybe traction control?? i get the same problem when its on..

 

[Cruznlife1]

checked your coils ? or the vc gaskets ?

 

[Pete02LSE]

Well...I tried to recreate with the traction control off...and...sure enough...it still happens. So...I suppose I can rule that out.

As for the vc gaskets and coils, I replaced the vc gaskets and plugs about a year ago and have been waiting on the coils because it hasn't tripped the SES light. Now, at a sustained RPM, you can hear a slight miss. So...I'm suspecting one of the coils may be failing. However, with no SES light, I can't believe it would make this thing hit a brick wall like it does.

Anyone think that the trouble is indeed an ignition coil (or coils)? Could it be the fuel filter? We got the car used and I don't know if it was ever changed. Currently, the car has 67k on it.

TIA,
-Pete
02LSE

 

[beaups]

if it's a"brick wall" like fuel cut I'm really betting fuel system...and quite possibly a clogged fuel filter. back in the old days before electronics complicated everything that was a dead giveaway symptom of a bad fuel filter.

 

[2001LS8Sport]

This sounds like a "tip in" problem. It could be fuel related...probably pressure since you don't complain of a problem other than from a dead stop. If the filter were plugged, the car should be laying down in top of 2nd or 3rd gear too...when it needs fuel the most. However, don't rule out a filter...I have seen them cause some strange problems.

Since you also notice a slight miss at cruising to go along with this, are you getting any codes at all? I'm wondering if you have a vacuum leak somewhere and it's going lean on you. Next, do you have something like a K & N filter on it? If so, clean your MAF sensor very carefully. Sometimes, those are over oiled and can coat the wire on your sensor and cause drivability issues. Make good and sure all your air inlet connections are good and you aren't getting unmetered air into the intake behind the MAF sensor. Last...it's possible you could have a TPS sensor that's bad. Those can go bad and give an intermittant reading when the throttle is mashed. It has to be a nice smooth transition. However, I haven't seen that problem in a long time now as manufacturers seem to have a handle on that. It used to be a common problem. Not any more.

I like beaups idea of the fuel system. I would start there with a new filter. But you need to check the pressures too. They need to jump dramatically when you hit WOT.

 

[Pete02LSE]

Update...tonight, I replaced the fuel filter which took a grand total of about 30 minutes...not bad at all. When I disconnected the tank side...wow and the crap that ran out. I've gone a good many miles on other cars without changing filters and I have NEVER seen this much crud pour out of the filter. I'm talking the consistancy of watery mud. And...looked like mud too. I cannot believe there was that much junk in it. As I am watching this crap pour out...I can't help but think it HAS to be my problem. But...alas...it wasn't. It still hits a brick wall in 1st...even with TC off.

However, one interesting point...the SST actually worked one time. Maybe I was holding my mouth just right and it worked. It really nailed 2nd...no chirp but...it def. hit hard.

Now, my question is...what should I try to troubleshoot next? I still haven't thrown any codes at least the SES hasn't tripped.

TIA,
-Pete
02LSE