jcarroll53

Hello guys (there's a TL;DR version at the bottom),

I have an 09 Cobalt SS TC that's having some serious issues. Before this happened, the car ran fine and when on full acceleration it would get anywhere from 18-20 PSI of boost. It first started about a month ago when the car would not make any power during acceleration and the boost would not go over 5 psi. I checked the intake, intercooler piping, etc. to ensure there wasn't any boost leaks. A few days later, started getting a weird sputtering from the engine and a CEL. Pulled the codes and saw that cylinder number 4 wasn't getting fuel because of a faulty injector (that was the determination of the code). I replaced the injector with a brand new one and cleared the codes. Car ran fine for a few minutes and then the code came back as well as a code for inconsistent pressure in the fuel rail. Pulled the fuel rail off and the injectors and had them cleaned. Put everything back together and cleared the codes. Car ran fine for a few minutes, then the same codes came back. Decided that I wasn't going to mess with it until I had the money to do so. Then at the beginning of this week something very strange happened. When I'm driving the car and have my foot on the accelerator, if the boost gauge creates anything past 1 PSI, the engine shutters and then the wastegate opens and there's almost no acceleration.

I called the local dealership and they said that they wanted to do a full diagnostic (for $120) because they aren't sure what the problem may be. I'm very weary of letting the dealership touch the car and wanted to know if anyone on this forum has had any similar issues and/or know how to resolve them?

TL;DR Version
Car was working fine. (Averaged 18-20 PSI)
Started getting boost issue. (Nothing more than 5 PSI at full throttle)
Confirmed no boost leaks.
Got CEL (Injector 4 no fuel)
Put in new injector and cleared codes.
Car ran fine for a few minutes, then new codes. (Irregular fuel rail pressure)
Cleaned the fuel system and cleared codes.
Car ran fine for a few minutes, then same codes. (Irregular fuel rail pressure, Injector 4 issue).
Now car sputters when boost is greater than 1 PSI.

Joe09

I had a similar problem with my SRT 4. I checked EVERYTHING when I no longer was making boost for some reason. I checked my vacume lines, cyl comp, fuel press..ect.
I had a smog coming up to reg my car, and took it in and failed right away. I took the car home, unbolted and cut my CAT out and discovered that the "honeycomb" in the cat was totaly deteriorating and clogging the exhaust. I used a air hammer and broke all the "honeycomb" material out, re-installed the cat and BAM! Problem solved.\
SO...check your catalytic converter.
Hope it helps and you get boosting again!

breds2k

iTrader: (1)

^Um no.


Unless dodge cats regulate fuel pressure that must be pretty cool.......

jcarroll53

I'll check out the CAT and see if that helps. But would the CAT being clogged really make the fuel line irregular pressure code and the injector 4 code?

jcarroll53

That's what I was thinking. I wouldn't consider myself a master at mechanics, but I do know my way around the engine and the CAT didn't seem like it would be making the fuel issues. I could see it making an issue with boost though.

umrdyldo

iTrader: (1)

your cat has nothing to do with fuel pressure codes. Don't waste your time.

jcarroll53

I figured as much. Any idea what could possibly be going on with the fuel issue? It seems like it is the root of the loss of boost issue.

Joe09

I'm not saying the Cat will cause ANY fuel issues. A clogged cat will ruin boost pressure, guess I should had worded that differently. The CAT is for emissions only.

tomj77

iTrader: (2)

I'm gonna take a guess here and say ur high pressure fuel pump is taking a crap on you. That or ur fuel pressure sensor on the rail. Haven't had an issue like that, but I have had a fuel pressure code and replacing the pump fixed that.

tomj77

iTrader: (2)

I'd it turns out to be the pump, easy fix, and while it's off fix all the head oil leaks around the pump and cam position sensor if it hasn't been done

jcarroll53

Luckily in Florida we don't have to do emissions testing, but it probably wouldn't hurt to check it out.

I'll start with the fuel pump then work my way to the regulator. I just noticed that when I open the schrader valve there is quite a bit of air in the line. Plus, the schrader valve is before the regulator, so fuel pump would seem to be the best candidate.

umrdyldo

iTrader: (1)

Can you please give us the code you were having to see what it is. Some are more obvious than others.

jcarroll53

So, I double checked the schrader valve and I'm getting a few big air bubbles. There's no obstructions in the fuel rail and the injectors shoot clean. I'll replace the fuel pump just to be on the safe side. Also, I noticed the fuel regulator is making a loud ticking noise (at least im pretty sure it's coming from the regulator), is this normal? Or is this a symptom of being starved?

@umrdyldo I do not remember the codes right off the top of my head. I'll see if I can have them pulled later this evening and I'll post them.

tomj77

iTrader: (2)

If I'm not mistaking , the pressure regulator for the high pressure side is built into the pump. And yes that round thing should be ticking.

SR Tech

iTrader: (2)

Check the 2 wire plug going to the solenoid on the hpfp. They made the harness so tight there that there have been plenty of cases of the wires pulling out of the connector. Other wise I'd say the hpfp is at fault