Help me find my lost power

[SHO#7]

I have a couple Gen 3's. My question is on my 96. The status of the car is 1996 with 125k, welded and 100k service done at 97xxx miles, transmission was rebuilt approx 250 miles ago. And just for FYI it IS one of the cam failure cars listed on V8SHO. And was caught when it was just a noise, and welded by one of the top 5 welders on the list.

My concern is this. The car just does not have the power that I have come to expect from a SHO. I feel that my 98 would absolutley destroy this car. It just does not scream up the tach like the 98 does. 1st gear seems to be just a strong as in the 98 but after that, they are not the same. The RPM's do not fly by like in my 98. And for referance, the 98 is by no means a freak. The best it has ever done was high 15's at like 92 or something like that.

My best way to describe the symptoms are that there is really no high end. Everything appears to work as it should, and there are no codes, IMRC is working. But much above 5k or so, the car seems to die off. My guess is that I am dealing with a possible clogged cat, but they check well with a temp gun. Is mine just slow? Is there something that I need to look for? Is there a benifit to running a catless Y pipe. I plan on replacing the rod bearings soon, so the Y pipe will be off. Is there any recommendations to removing the cats?

Sorry to ramble, it is just hard to explain. Any ideas or imput is much appreciated.

Mike

 

[95SHO32]

Is the ircm working? ck the cable for tension. Any codes that might point to any problems, Have u run koeo ?

 

[Ian Macoomb]

If you're trapping 92 your car is running well. The cats couldn't be plugged if you're running that fast.

How about taking both cars to the track to find out if there is indeed a difference. Or head to the track with a local group. The lack of low-end torque can fool you into thinking the car is slower than it is. For example, every GM rental car I get with a V6 (I rent quite often) feels quicker but most are mid 16 second cars (and my V8 is a low 15 second car most of the time).

 

[Slo-Sho]

Possible 125k on the fuel filter?

 

[SHOtimer]

The fuel pump could be worn out denying the adequate fuel supply needed.

Doug

 

[SHO#7]

The 98 is the car that traps around 92. She is healthy. The 96 is the SLO SHO for the moment. Fuel filter is new, plugs have around 28k, I have run KOER and KOEO. I have a bad relay on my SAI pump but that is it. And the IMRC is working 100%. Thanks for the suggestions. If anyone comes up with more, let me know.

Mike

 

[Sagabu]

Who rebuilt the tranny ? Might they have used a SLO TC ? I heard that Amco was doing this and they have different lockup characteristics . Is the loss feeling primarily around 60 or so ? Is the new tranny cycling like it did . At about 60mph just driving along , does the idle rise and fall slightly and the A/C cycle ? It SHOuld .
Have you checked for stored codes ? Any good high end auto shop should have a good scanner that will dig up trans codes . These codes may not trigger the SES . Only a good quality scanner will find them . They could also check fuel pressure .
Idea , take it to a competitors tranny shop and they may scan it for free if they think they are getting one over on the comp ?

 

[Mr Anonymous]

If you looked at Mike's sig you'd have seen who rebuilt his tranny...

Mike, I found your lost power. It's under my hood! Sorry, couldn't resist.

Some of these cars are just slower than others. It could also just be a perception thing. I'd say bring them both to the next local dyno day and see what the real numbers are that each are putting down. If the '96 is more than 5%-10% lower than the '98, then you'll definitely want to start digging deeper.

 

[SHO#7]

If you looked at Mike's sig you'd have seen who rebuilt his tranny...

Mike, I found your lost power. It's under my hood! Sorry, couldn't resist.

Some of these cars are just slower than others. It could also just be a perception thing. I'd say bring them both to the next local dyno day and see what the real numbers are that each are putting down. If the '96 is more than 5%-10% lower than the '98, then you'll definitely want to start digging deeper.

I agree with the decision that it just may be one of the less powerful ones. I also am starting to think that it may have to do with how it was broken in, and maintained. I know that when I canged some maintence items around 120k, it was the first time that they were ever looked at. For example, the cabin air filter had a pine tree growing in there. It made the car smell great!

And yes, I rebuilt my transmission. And the Torque Converter is a Furnace Braized TC with factory stahl.

 

[NC_SHO]

Secondaries stuck closed or IMRC broken or cable broken or stretched? Mine was a dog at high end when I had the IMRC removed.

Richard Wills

 

[SHO#7]

Secondaries stuck closed or IMRC broken or cable broken or stretched? Mine was a dog at high end when I had the IMRC removed.

Richard Wills

IMRC works as it should. I took the car on a 600 mile trip and she seems to be acting better lately. Maybe she is just old, and I am comparing her to two other cars that she is just not like.

 

[SHOZ123]

Disconnect the battery to do a brain drain then go drive the numbness out.