Thread: Breaking up under boost

Ok, so some of you know my car by now...for those that don't, it's a B13 SE-R with a BB DET in it. Stock T25, 'bout 13/14 psi, built internals, FMIC etc.

Now, it's got a JWT ECU set for 4bar...although I haven't checked fuel pressure yet...but I've only recently been having this issue.

So what's happening is when the car boosts, right about 10psi or so, it starts to sputter, real bad. I've checked for, and fix all the small boost leaks that I could find...but that was without doing an actual boost leak test (will do that next time I get to my friend's shop/house). After that, I turned the boost down...

So now, after that, Rob and I were going for a ride tonight and I was just giving it like 5ish psi, and we started to smell the cat burning up, you know...that rotten egg smell. Could the cat being clogged cause that problem? Rob has an extra high-flow cat I can put on...so I might try to do that soon. But do you think that could be the issue?

Rob and I looked around and searched a little...but didn't really come up with a sufficient answer.

Any help/tips/ideas are MUCH appreciated. I want my beast back!!!

Check you fuel pressure. Might have been running @ 3bar maxed out the 370's(if you have them), ran the car lean melted the cat. Check your plugs, they might have tell-tale signs of either detonation or preignition. If anything reduce the gap on theplugs change the cat asap and see what happens then.

My .02 cents

uh oh. Yes sir, the cat is getting very hot. Either from too much fuel, or running really lean. Get a fuel pressure gauge asap. Could be a fuel pump starting to go as well. For some reason I have seen a couple of these fail lately.

Yeah it does have 370's and a Walbro 255 pump (sorry for not including that). Didn't hear any pinging/knocking or anything. It just acts almost like a boost leak...but at 10psi. I need to get under the car again and check the couplers on the FMIC I think.

Ok, so the ECU is set for 4bar...I need to make sure the fuel pressure is also at 4bar. I'll also pull the plugs, and give those an inspection.

I should be able to check this stuff this weekend, until then...no boost for me.

Thanks for the input guys.

Well the rotten egg smell is typically the cat. You mentioned it has a built motor... was that cat in the car when the motor blew previously?

I ask because I just built a motor for my car. The old motor had 170, 100, 170, 170; so it was pretty bad. Anyhow, even more recently I put in a new downpipe and exhaust with a test pipe. The old cat I took out (that was in there for the destruction of the old motor) was devastated. It looked like about half of the honeycomb was gone with loose half-melted chunks still rattling around in there.

When the motor blew? I don't know...I don't know that the old DE ever blew at all. The DET was built before it was put in the car, and I bought it that way.

Yeah, I think I'm gonna stick a gutted shell on there. Might just free up some more ponies.