PI swap, not feeling power, help!!!!

[bluestreak_96gt]

okay I just did the complete head swap on my 96 gt with fully race ported heads with comp. vavle job, bbk short tube headers. I already had flow master exhaust, including offroad H-pipe, cold air intake, performance chip by superchips and 3:73 prior to head swap. Now my question is... After I completed my swap I took it for a test drive and it seems to not be pulling throught the RPM range. It seems real sluggish, like something is restricting it. I have not got a tune done yet, i don't think that it would make it lag this bad in torque and or horsepower. The car seems to be getting slower the longer i have it. When I first bought it 3 months ago, I could burnout out through 3rd gear, and i have the same tires as threes months ago with less tread and struggle to burnout throw second, WTF! Does anyone have a clue? Could it be the computer going bad, or a sensor f-ing up, and anything hell any suggestion at this point would be great. Everything was put together correctly. No left over bolts or nuts, lol.... but seriously does anyone know or have an idea? Thanks, Rob :damnit:

 

[00s281sc368]

get a dyno, it will tell you what U have

 

[HoustonGT]

You definitely need a TUNE after all that work. Get it dyno-tuned and itll be a beast compared to before the swap

 

[300bhp/ton]

okay I just did the complete head swap on my 96 gt with fully race ported heads with comp. vavle job, bbk short tube headers. I already had flow master exhaust, including offroad H-pipe, cold air intake, performance chip by superchips and 3:73 prior to head swap. Now my question is... After I completed my swap I took it for a test drive and it seems to not be pulling throught the RPM range. It seems real sluggish, like something is restricting it. I have not got a tune done yet, i don't think that it would make it lag this bad in torque and or horsepower. The car seems to be getting slower the longer i have it. When I first bought it 3 months ago, I could burnout out through 3rd gear, and i have the same tires as threes months ago with less tread and struggle to burnout throw second, WTF! Does anyone have a clue? Could it be the computer going bad, or a sensor f-ing up, and anything hell any suggestion at this point would be great. Everything was put together correctly. No left over bolts or nuts, lol.... but seriously does anyone know or have an idea? Thanks, Rob :damnit:

there are so many possibilities here.

But the key is if its not pulling thru the rev range there is a problem. However as you don't know what it is I would suggest not beeing to hard on the car as it could go BANG.

If you put new valves in then you should have taken it gentle for 200-500 miles to break it in, if you went straight out at WOT you may have buggered it all up.

As for the fault, well it could be electrical, is it missing? Check plugs and leads (is the coreect lead attached to the correct spark plug?) and such. Is the ECU throwing any codes?

It could be fuel, as in restircted flow rate, injector blocked.

What gaskets where used? It might be a compression leak? Is it useing oil/water. Is the engine smoking?

Although you say it was put together correctly, are you sure? Even pros make mistakes and having no parts left over doesn't mean everything is where it should be.

See what I mean it could be one of hundreds of things, some simple some expensive. Best bet is get it tuned and the ECU checked try and locate the problem then you can sort out a solution.

 

[edbo]

Remove the Superchip 1st since it was only set for original setup. Reset with battery disconnect. Then Get The Tune!

 

[TGJ]

Check all the hoses running from the intake. It is possible that you have a vacuum leak or a vacuum hose may have collapsed internally.

 

[COramprat]

Remove the Superchip 1st since it was only set for original setup. Reset with battery disconnect. Then Get The Tune!

I agree...the chip is tuned for the old set-up. Try removing it and let the computer learn the new info. You will still have issues in the mid range because of the better airflow but it should compansate somewhat. If that doesn't solve some of the problem you need to get that chip reburned for the new stuff.

 

[bluestreak_96gt]

there are so many possibilities here.

But the key is if its not pulling thru the rev range there is a problem. However as you don't know what it is I would suggest not beeing to hard on the car as it could go BANG.

If you put new valves in then you should have taken it gentle for 200-500 miles to break it in, if you went straight out at WOT you may have buggered it all up.

As for the fault, well it could be electrical, is it missing? Check plugs and leads (is the coreect lead attached to the correct spark plug?) and such. Is the ECU throwing any codes?

It could be fuel, as in restircted flow rate, injector blocked.

What gaskets where used? It might be a compression leak? Is it useing oil/water. Is the engine smoking?

Although you say it was put together correctly, are you sure? Even pros make mistakes and having no parts left over doesn't mean everything is where it should be.

See what I mean it could be one of hundreds of things, some simple some expensive. Best bet is get it tuned and the ECU checked try and locate the problem then you can sort out a solution.

ya it has all new gaskets and such.. we pulled the superchip and still need to clear the computer. it feels like the timeing is not advancing at all, it doesnt progressivly pull at all. hmmmm????

 

[CanadaStang]

ya it has all new gaskets and such.. we pulled the superchip and still need to clear the computer. it feels like the timeing is not advancing at all, it doesnt progressivly pull at all. hmmmm????

Reset the EEC, if it still runs the same, do a compression test. If all cylinders on one side all consistently higher than the other side[20 psi or so], then your cam timing is out.

 

[twogts4us]

your cam timing is out.

 

[Orions98GT]

heh was gonna say, when I got my PI swap it felt like a kick in the pants

 

[UhadMEatGT]

You need retuned....period.

 

[tomustang]

heh was gonna say, when I got my PI swap it felt like a kick in the pants

most people don't tend to re-gap the spark plugs after the higher compression. which will lead to a signifigant gain. after i did my swap (98 GT) it didn't feel like much until i gapped the plugs to .035. either that or the cam timing is off, like what canadastang said.