walleyealx

2003 Silverado SS w/ P-1SC stock 4" pully. Truck has new NGK TR6 plugs about 300 miles ago. Just put some 60lb Siemens Deka injectors in about 50 miles ago. Everything was running great, came back from flying out west for a few days and starting to feel some problems. Everything seems fine when driving normally, but at WOT and RPM's above 3500 or so the engine seems to chug/sputter. I replaced the fuel filter and it didn't seem to make a difference. Do you think this is the stock fuel pump on it's way out? (VROOOOOOOOOOOOOOOOOOOM DUH DUH DUH DUH DUH DUH ---rhythmic)

I should preface this by saying that is has been throwing lean codes since I got it (171, 174) and one time it threw a couple O2 sensor codes. Performance is not affected by the codes. I don't know if the lean codes and the other issue are in any way related at all.

Thanks ahead of time.

Atomic

iTrader: (42)

Sounds that way...do you have a wideband on it?

walleyealx

I do not, and I would be lying if I said I really knew what one of those did. Also, I still have the FMU installed despite the fact that I have the new injectors. I don't know if that matters.

Atomic

iTrader: (42)

Who tuned it? They should be able to tell you rather easily if they hook it up to their computer whats going on.

walleyealx

It's a guy named "Zippy" over on the silverado SS forums. He was whom most of them over there recommended. The problem is he lives across the country.

Atomic

iTrader: (42)

Well you would need to hook up a fuel pressure gauge then and see what its doing.

walleyealx

I see that they sell some locally. I read that you just have to hook them up to the Schroeder valve on the crossover to the fuel rail. Will I be able to tell anything if it isn't under load or will I have to route something into the cab?

Atomic

iTrader: (42)

You may be able to tell at idle, but you could always keep it hooked up and go for a test drive with it taped to the hood

batboy

iTrader: (6)

I'm pretty sure the fuel pump is supposed to be upgraded when you installed a SC. When you recently upgraded the injectors, was it retuned? It should have been of course. A wide band tells you what your air/fuel ratio is running at, which is critical with power adders. Lean codes are not supposed to happen if all is well, you need figure to this out immediately.

walleyealx

It is definitely tuned for the new injectors. The SC was installed before I got it, but it seems like the previous owner pretty much bought the kit and threw it in there without doing any other modifications so I'm still trying to figure it out.