Jeep Wrangler Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
335 Posts
Discussion Starter #1
Well this new rebuilt 4.2 with MC2100 has been running great until it started losing power big time! Goes up hills very slow but runs on flat ground just ok. Doesn't backfire and doesn't hesitate but when you step on it it just doesn't go. Sounds like I have a huge cold air intake on it like a Honda. So I guessed fuel issue like fuel pressure. To me it seemed like it just wasn't getting enough fuel. So I did a fuel pressure test.

At idle it stayed close to 2psi and then at around 2500rpm's it went just over 2psi. I did a pressure check before and after the fuel filter with the same results. So I don't know if this enough pressure or not. I would love a good answer for this.

I did a vacuum check and at idle the max vacuum I could get out of the carb was 21" and I'm somewhere around 1000 feet sea level.

So now my other question is when the jeep did start losing power I also noticed my CAT starting to leak and maybe swell up but I can't tell if it is truly swelling but it leaks loud when under a full throttle situation and not at idle. It's behind the skid plate so I can't tell where on the CAT is the leak but I can feel it and hear it a lot when someone revs up the jeep while I'm under it. So do you people think that my BRAND NEW CAT is already clogged? This CAT is from Napa and I've never had bad exhaust parts from them but there is a first for everything I know.

Again I started to lose a lot of power when I started to hear the CAT leak. I'm think the CAT is bad and possibly swelling or something like that and falling apart inside.

Thanks. Ken
 

Attachments

·
Registered
Joined
·
335 Posts
Discussion Starter #3
well yeah but if it wasn't the problem I wasn't going to do it yet. The exhaust is welded and I don't have the ability to work on the exhaust very well and I didn't want to have to worry about it yet.
 

·
Registered
Joined
·
3,939 Posts
when I replace a fuel pump I usually go to an electric one.the ones I buy are 4-7 pound pumps..I use this same pump if it is a 2 barrel or a 4 barrel.I have one now on a holley 4 barrel feeding a nearly 400 horse 350 and it always has plenty of gas available..so,I would think that 2 pounds would supply you with enough but I can't swear to it.by your problem starting at the same time as the cat problem makes it a likely suspect
 

·
Registered
Joined
·
742 Posts
well yeah but if it wasn't the problem I wasn't going to do it yet. The exhaust is welded and I don't have the ability to work on the exhaust very well and I didn't want to have to worry about it yet.
Start worrying. It's the damn cat again. It's dripping AND swelling because its clogged and the pressure has no place to go. Without knowing how to weld I suggest a trip to a muffler shop.
 

·
Registered
Joined
·
335 Posts
Discussion Starter #6
when I replace a fuel pump I usually go to an electric one.the ones I buy are 4-7 pound pumps..I use this same pump if it is a 2 barrel or a 4 barrel.I have one now on a holley 4 barrel feeding a nearly 400 horse 350 and it always has plenty of gas available..so,I would think that 2 pounds would supply you with enough but I can't swear to it.by your problem starting at the same time as the cat problem makes it a likely suspect

Thank you. That's what I was looking for. I wasn't sure at all if it was enough pressure but I knew it didn't need to be much. I heard it was suppose to be I thought 3-5 psi but then I heard 1-3 psi. I wish I knew what my pressure had been before when it ran really good.

Start worrying. It's the damn cat again. It's dripping AND swelling because its clogged and the pressure has no place to go. Without knowing how to weld I suggest a trip to a muffler shop.
I feel the same way. Its prolly the stupid cat. I don't know if I will do a after market one or just gut it out.
 

·
Registered
Joined
·
335 Posts
Discussion Starter #7
If you guys are still reading these post I just wanted to say it was a bad cat. It completely fell apart inside.
 
1 - 7 of 7 Posts
Top