Huge Power Loss On My 3.8

[Dawizman]

Alright, I have been fighting this problem for the last week and a half to no avail, and its just been getting worse, and to top it off, The car isn't throwing any dtc's.

To start, its a 1996 Firebird, 3.8L M5.

When my car is cold / just started I can barely get the rpms up to 3k rpm and it lacks all power.

Once the car gets up to operating temp, it has no power at all and wont get past 1.5-2k rpm.

I barely got back home today after doing some work on the car at our warehouse. I decided to get out and feel the exhaust. Its extremely hot and not as much pressure as it used to have. It almost feels like the blow-drier, just a really dry heat.

It also dosen't have the growl my exhaust used to have with the flowmaster 40 i have on it.

After reading through posts on the forums all day I'm starting to think it might be a clogged cat.

So far I've replaced the following parts with no effect:

-Spark Plugs (NGX Tk55 Iridiums)
-Spark Plug Wires (OEM's from partsource)
-ICM
-All 3 Coils
-Fuel Filter
-PCV Valve

I also cleaned the MAF, threw a couple bottles of STP injector cleaner in the tank & topped it off with 91 octane.

Fuel pressure at the rail is normal under all conditions as well.

Should I change the cat, or could it be something else do you think?

[terminaldegree]

Re: Huge Power Loss On My 3.8

My gut reaction would be that your cat is, indeed, shot.

[Dawizman]

Re: Huge Power Loss On My 3.8

My gut reaction would be that your cat is, indeed, shot.

I sure hope so. The only other thing I can think of as injectors, and I simply dont have the time for that. I'm supposed to be driving about 700km across the province on Wednesday and still have work tomorrow.

[Harrison]

Re: Huge Power Loss On My 3.8

probably is cat...good oppertunity to get a high flow. could be the clutch goin out too...but id assume its the cat. could be the maf sensor going out too. does the car shutter, irratic rpms, turn off, feel like uneven power?

[Dawizman]

Re: Huge Power Loss On My 3.8

probably is cat...good oppertunity to get a high flow. could be the clutch goin out too...but id assume its the cat. could be the maf sensor going out too. does the car shutter, irratic rpms, turn off, feel like uneven power?

Its definately not the clutch. I've had clutches go out it everyway imagineable (Not all on my vehicles, freinds too) and this is nothing near that. The enging runs horrible, even in neatral. Once it gets up to about 190* F it barely starts.

Also, I doubt its the MAF. If I unplug it, I get a code and it runs way worse, when I plug it back in, it goes back to 'normal' AKA less messed up.

I'm going to get my car in tommorow to one of the exhaust shops to get a new cat thrown on. How much should I expect to pay for a cheap CAT & getting it welded on? I dont want to spend too much more because I'm trying to save up for a down payment on an LS1 T/A.

[Loochy88]

Re: Huge Power Loss On My 3.8

did you pull the MAF and visually inspect it?

[Phate]

Re: Huge Power Loss On My 3.8

did you pull the MAF and visually inspect it?

I agree on the MAF or the Cat, dont see the clutch doing what you describe.

[Darkshadow188]

Re: Huge Power Loss On My 3.8

I'm going to put my invisible money on a clogged cat. Had the same problem. Your SES light will come on soon(if not already). A new cat welded cost me about $70. It's not something that will hurt your wallet too bad. Depending on the condition of your 02 sensor, I'd replace that too.

[Dawizman]

Re: Huge Power Loss On My 3.8

UPDATE::

Work up this morning to go to work, went outside & scrapped the frost off the windows and then tried to start the car. Guess what, it wouldnt catch. It just turned over and over, but wouldnt catch.

Any ideas on what to check now?

Could this be misrouted plug wires that burned on a manifold?

The fuel pump was priming the system just fire, and it turned over without any problems. It even built up a bit of oil pressure as it cranked.

[Dawizman]

Re: Huge Power Loss On My 3.8

Well, I found out why my car wont start. I opened up the fuse block under the hood and checked all the fuses. Turns out the injector fuse was blown. So I replaced it with a new one, went to start the car and it caught for half a second, then died. I went and re-checked the injector fuse, and sure enough it was blown again.

What are your thoughts on why this would happen?

Could bad injectors cause a problem like this? (I really dont want to replace all the injectors) Or is it limited to a short in the injector wires?

[astroglyph]

Re: Huge Power Loss On My 3.8

I'd visually check all the wires for wear marks, and make sure all your connections are tight. maybe also unplug each of your injectors electric connectors and cleand the connections.

[Dawizman]

Re: Huge Power Loss On My 3.8

Well, good news (kinda).

I found out why that fuse keeps blowing. When I replaced the ICM I wedged the injector wires for the rear drivers side cylider (cant think of the number) in between the ICM block and the braket.

Once it warms up today, I'm gunna go out and pull the ignition assembly off and fix those wires.

[Dawizman]

Re: Huge Power Loss On My 3.8

Well, just thought I'd post an update.

Last week I finally took my car to GM to get diagnosed because I was tired of throwing money blindly. Well it was the catalytic converter that was at fault. For now, until I get my new exhaust in, I just chopped the entire system off right before the cat.

This car is louder than the 305 running open headers in my old monte.

[Fuelman]

Re: Huge Power Loss On My 3.8

Yes, I had the same thing happen to my Camaro.
It got worse and worse till I could'nt drive it!
If you can afford it I would go ahead and get a high-flow cat and exhaust.
I got a Carsound cat, SLP install kit"S-PIPE", and Rumbler cat back.
Cost around $400.00

[Dawizman]

Re: Huge Power Loss On My 3.8

I've got a high flow cat on order and im going to put a cherry bomb after the s-pipe and then run it out a flowmaster 40 exiting in front of the rear tire on the passenger side.