As some of you may have read, I'm having some issues getting the car to run right after my D1SC install. The Procharger is installed on a stock internal engine, with 60lb injectors, Warlboro 255 fuel pump, and NGK TR6 plugs being the only other new mods outside of those in my sig. In a nutshell, here is the problem...

I got a base tune from Frost to get the car running so I could drive it to get it tuned. I hooked the computer up, and tried to start the car. It took several tries, but finally started. It idles rough, but I wasn't alarmed at the time...figured it would be pretty normal with the new tune/mods. After warming to operating temp, I tried giving it light throttle...the engine stalled, but slowly brought the rpms up to match the throttle position. I let the engine idle for a while, thinking the PCM might need to learn fuel trims, etc, but the conditions still haven't gotten any better. If you hold the throttle at, say, 2000rpms, the engine will hold speed for a couple seconds, but will eventually drop 2-300rpms and surge back up. It surges badly at basically any held throttle position, and stalls every time you give it gas off idle.

I threw a p0300 code when I first fired the car up after installing the computer, which I looked up (random misfire) and then cleared. I have not gotten a code since, but the symptoms still remain. I have checked every possible angle for a vacuum leak, and hosed pretty much the entire manifold and every hose and connection with carb cleaner, but to no avail. I checked the vacuum on the gauge, and it shows 20 and holds steady...no bouncing around or erratic readings. Fuel pressure is at 63 at idle, and I've yet to see it drop under 60 at any throttle level. I pulled the plugs/wires tonight, and rechecked the gaps. Plugs are gapped at .030, but look incredibly clean. There is virtually no sign of combustion anywhere on any plug, especially the tip, with the exception of a BB-sized brown spot on the ceramic of each plug. There is no soot, or even a tan or white mark to be found on any plug.

I'm stumped on this. I emailed Steve at Frost, and he's certain its a physical issue and not in the tune. I have no reason to doubt this, but at the same time have no idea where to look next. This car ran like a top before I started the Procharger install, and I've double and triple checked the installation of all components, including bypass valve. The only things different on the engine itself are the injectors and the plugs.

Any help or suggestions here would be greatly, greatly appreciated.

 

Lower the fuel pressure to stock 58 psi. and check the maf.

 

+1

Did you tell Steve your rail pressure ? That will make a difference so if you told him 63 psi then leave it alone, but if you didn't he assumed it was stock pressure so you should lower it to 58psi.

 

I told Steve the fuel system upgrades when I ordered the tune, and he didn't seemed alarmed when I emailed him and told him the rail pressure was 63. How do I lower it? And what should I look for with the MAF?

 

Well if you told him the rail pressure was 63psi then I doubt that is your problem. If you have a stock regulator you cannot adjust pressure anyway. As far as the MAF, the only thing I can think of is to try and clean it or try another one. They sell MAF cleaner at auto parts stores.

 

Alright, I'll grab a can of cleaner and check it out tonight. I'll do a backflip if its something this simple.

 

did you check plugs and wires? you need to make sure it is not throwing any codes.......and the misfire code could indicate an issue......it could be something really simple

 

I pulled the plugs/wires last night, and rechecked the gaps. Plugs are gapped at .030, but look incredibly clean. There is virtually no sign of combustion anywhere on any plug, especially the tip, with the exception of a BB-sized brown spot on the ceramic of each plug. There is no soot, or even a tan or white mark to be found on any plug.

Wires are in good shape, and I have tried two sets.

I'm not throwing a code anymore. I threw the code early last week and haven't thrown it again since.

 

Then my guess is the MAF....or a vacuum leak

Clean the MAF or try another one and check for vac leaks first

take a video of what car sounds like when u try and start it and I might be able to help more

 

Seems like if I had a vacuum leak, I wouldn't be pulling 20 at idle. I'd also think the reading would be bouncy and erratic, which it's not. I could be wrong on that, though. Honestly, I don't even know where to begin looking for a leak again...I've sprayed damn near a full can of carb cleaner on every seam, hose, joint, and fitting on and around the intake manifold and every vacuum hose, and found nothing.

Will definitely be checking the MAF, though.

 

Im 99% sure we ruled out a vacuum leak when Mike and I were out there. MAF is a possibility.

 

MAF is the one thing I haven't really delved into yet. Going to pull that bastard off tonight and check it out.

 

Umm how r u getting 63 psi at the rails with a stock regulator? I think ur either drowing those plugs. or you have a bad sensor some where. make sure 100% their are no leaks arund the map also.

 

Just telling you what my gauge reads. It's an Autometer electronic fuel pressure gauge, and the sending unit is installed on the end of the rail where the Schrader was...

I borrowed a friends scanner and wrote everything down. Numbers are really erratic and jumpy...no codes present and none pending.

Calc Load: 2.3%

STFT B1: -3.1 to -4.6 (jumps around)

LTFT B1: 0

STFT B2: -5.2 to -7.8 (jumps around)

LTFT B2: 0

MAP: 9.1

RPM: 800ish

Spark Adv: 20-22

IAT: 59

MAF: .882-.951

TPS: 0

O2S B1 S1: .050 - .865 (jumps around a lot)

STFT B1 S1: -5.4 to -7.8 (jumps around)

O2S B1 S2: .440 - .805

STFT B1 S2: NA

O2S B2 S1: .045 - .845

STFT B2 S1: -6.2 - -9.3

O2S B2 S2: .440 - .825

STFT B2 S2: NA



Fuel Pressure (on gauge): 62psi
Vacuum: 20


Curious to hear anyone's thoughts on this...

 

fuel trims look fine

 

What do you get when you give it a little gas where it hesitates?

 

For which value? I'll have to go look again...

 

All if possible. I can always bring my HP Tuners out there and we can scan it and record what happens.

 

I can't log this stuff...I'm just writing down the live data. No way to see what its doing on all values when it hesitates.
I may get you to come out if I can't get this sorted in the next couple days.

 

I have no problem coming out there again, Im off Friday and Sunday but I hope to fix my car on Friday.