Today, I left my house and had no power whatsoever. I cleaned the MAF sensor and throttle body to no avail. The car goes like normal under minimal boost but once it hits even 2PSI I lose power and 20-30 takes longer than 0-60 used to. This just started this morning. Is it possible that the cat is clogged up? I haven't looked at it yet to see if it's glowing but I know that I've narrowed it down to fuel pressure or the cat. Also, if I rev it in neutral, it bounces off the rev limit very slowly. I mean VERY slowly.

 

Check to see that all your intake hoses are connected tightly and have no holes in them. If you have a leak somewhere, it will kick the car into limp mode. Been there done that.

 

I checked all the hoses. Nothing is damaged. I can't figure it out. I figure it could fuel pressure or the cat plugged up.

 

Okay, update on the situation. I have checked the fuel pressure and I basically have none whatsoever on the rail. I forgot to check pre-filter pressure but I'm certain that, when pressing the valve open with a knife sprays you and the entire area under the car, there's good pressure. The rail might have .5 PSI. That's HALF of 1 PSI... It's enough to run but not more than that. Is it possible that the filter is plugged up? The new pump has a new screen on it and that should catch most what it would pick up. I also revved the car for a minute or so to find that the turbo, not cat, was glowing. WTF? That can't be good for it.

 

The exhaust can glow if you have a plugged exhaust or you rev'd it very high for awhile. Is that what you did before you noticed it was red hot?


As for the fuel, I would suggest rechecking the rail pressure. The car would not start, idle or run on .5psi. If the car runs and you can drive it....its not the pressure at the rail.

Next, conditions that cause this are boost pressure not being able to build. So, you need to double check the hose connections and take a look under the hose that goes to the throttle body where the IAC hose exists, it is common for those to split in that location. Its under it, you cant see it by looking at it. Pull it off and inspect it.



If there truly is no leaking then you need to look at the wastegate and make sure the actuator is holding closed.

Here is the ultimate test. Before I go into this though you need to understand that if you are not extremely attentive to the boost you can damage the engine. Do not do this if your boost gauge is not working. The max of your boost gauges white area is 10psi...dont go past it with this test.

Test: Disconnect the wastegate pressure line at the actuator(so it cannot open). Take it out for a drive, while staring at the boost gauge begin to drive putting a little more load on it as you go. You will have your answer within one block of driving. I dont want to scare you with doing this, just be attentive and everything will be fine. I have done this several times.

 

My boost is fine, the gauge is working. My fuel pressure is extremely low. I know for a fact that there is just enough pressure for it to run. The gauge I used reads in 1 psi increments and it hardly moved. I opened the valve at the rail and it barely pushed fuel out. My question is this. Would the filter filter be able to cut out the fuel pressure that badly? I just rebuilt the turbo and everything there is fine. I double checked the wastegate, and I already checked for vacuum leaks. The car drives fine with minimal throttle. When it builds boost pressure, it acts like its starving for fuel. In fact, it loses what power it had under boost. It wont build rpms at all.

 

It absolutely could but it's not likely. A fuel filter filters out small particles. It plugs up slowly in almost all cases and to start you'd have problems with high speed fuel delivery because being partially plugged it would restrict flow, the capacity of fuel transferred long before it started to restrict pressure.

If it's running you have way more than .5 psi. If you are reading "metric", maybe, just maybe it will run at .5 kpa (15psi) but I doubt it will. I'm not sure what the minimum is but I'm very sure it's over 20psi.

Might be the pump, pump relay or fuel pressure regulator. Pull the vacuum hose off the regulator and see if it's wet inside. If it drips from the regulators nipple or there is raw fuel in the vacuum hose the regulators diaphragm is ripped and it's junk.
If you're in doubt about the filter, pull it and replace. Once you have it off blow through the new one and then through the used one. Remember it's slightly restricted because it's wet with fuel but if your cheeks hurt from trying to blow through it, it was over due.

 

Well, I retested the fuel pressure at a different store and it read about 20PSI. I went ahead and replaced the regulator anyway. I did, however, finally find a hose leak. it was on the throttle body hose at the base of the clamp. It was small and hard to see from the outside but once I pulled everything apart, the inside was busted way out. I'm ordering another factory hose for now and I'll upgrade down the road when I have the money to. I spent all of it on my fuel pump.

 

would low fuel explain the turbo glowing though?

 

Sure would...running lean = running hot. That's what destroys motors when they run too lean

 

I thought lean conditions would cause the turbo to glow but it wouldn't, excess fuel would. The mix burns longer when it's rich and it continues to burn hot through the turbo. I figured it out though. The injectors were compensating for the fuel pressure by opening longer so I needed a regulator anyway but my problem is a busted intercooler hose. It was busted in such a way the you couldn't look at it and see it, I had to bend it to see the hole.

 

Thank you Boxpin

 

Yes, thank you Boxpin. I looked at it all around the outside but couldn't see a busted spot. I took it completely off and looked through the inside only to find a MASSIVE gash. I don't know how I couldn't see it from the outside, it's easily an inch long on the inside.

 

Glad you found it.