Fuel Pump Question

[4-cam]

Both pumps were replaced, Fuel filter is new, and I have a consistent 52 psi on the fuel rail all the way to 7000 + rpm. As she passes the 7k mark it throws the code. It didn't do this last year with he old injectors and coils, but had the dreaded flywheel knock and a didn't run very strong on the bottom end. Past 4k rpm it took off and ran great. Figured the injectors were toast as they were the originals. The only difference between now and last year is new MSD coils and new Accel injectors. The original prom was reprogrammed so I don't have another one to try.
Corey programmed my prom for the secondary removal so I will contact him to see if he added some fuel to go along with the top end porting.

[tomtom72]

Here is a fwiw on the coils.....and this is based upon all the reading I did after I bought my Jegs Hi-performance coils. Waaay back screamin' deamon coils were the rage, circa 04 & back. Everyone who used them had issues with coil break down fairly quickly & some not so quickly.

My take is based on the info at GM. They list two different P/N coils for a waste spark system: ours and all their other cars that used a waste spark system. The specs are the same, so what is the difference? Where the coils live is my conclusion. Ours live in a hostile place for anything electrical. If you cross reference any of the other GM motors that use a waste spark system the aftermarket coil P/N is the same as what they sell for our car.

I bought a real GM LT5 set and took out my Jegs coils after about a year of wondering if I was going to suffer a coil failure due to heat. Okay, all this is JMHO supported by no testing or knowledge what so ever....just looking around at what happened to all the aftermarket coils.

Yea, if a little juice is okay, then a lot of juice is better? I fell into the trap, and then I did the reading! LOL

[4-cam]

Thanks for the info as another opinion is always helpful, but I don't think its the coils. I haven't run the car more than 1/2 tank of gas thru it since the injector / coil install. Definitly a fueling issue. No miss and runs smooth, just lean on all cylinders.

[Starman]

Here are a couple of dumb suggestions:

1) verify that you have the right flow rate injectors for the car. I know one of them is physically unique to the car, but the other one is physically pretty unversal to all cars with port injection. I would note that the ACCEL/DFI online catelog does not list injectors for our cars - I went with the RC myself.

2) It seems like my fading memories recall that these cars had a fuel shutoff feature around 7400 - 7600 rpm. It might be that your tach is lagging a little and you are bumping the fuel shutoff.

3) This is really rusty, but if you have the ability (laptop) take a look at the block learn value and the O2 sensor values. With a lot of mods, you might be slightly lean all the time and need your prom tweaked again.

Best of luck

[4-cam]

No suggestions are dumb and thanks for the reply. The accels's that I used are the same ones that many others have used and Mark H recommends so i am comfortable with the injectors. I just got my cable for some data logging on my laptop, so I will be playing with that this weekend and hopefully post up once I get some data to look at.

Regards

[scottfab]

Originally Posted by Starman

2) It seems like my fading memories recall that these cars had a fuel shutoff feature around 7400 - 7600 rpm. It might be that your tach is lagging a little and you are bumping the fuel shutoff.

Something familiar about this. I've not often hit the rev limiter (I think stock limit is 7200) but when it hits maybe the side effect is a lean code set?
I just can't remember. Anyone?
I guess I'll just may have to find out again. Good an excuse as any.
"but officer I was testing the rev limit for a friend......"

[tomtom72]

fwiw the stock is around 7200 I think, and as I have hit it in 2nd mostly I have never had a lean code set. And two times at least I have hit the limit in a "hard" fashion....not even realizing I was there, as it just seems to want to go on forever in 2nd, I have run over that limit and thought I had just broken my motor. It's as if the motor shuts off.

[scottfab]

Originally Posted by tomtom72

fwiw the stock is around 7200 I think, and as I have hit it in 2nd mostly I have never had a lean code set. And two times at least I have hit the limit in a "hard" fashion....not even realizing I was there, as it just seems to want to go on forever in 2nd, I have run over that limit and thought I had just broken my motor. It's as if the motor shuts off.

Well there goes my excuse to test it. I guess I'll just have to answer "yes" when I'm asked if I was on my way to a fire

I wonder if maybe one of his new injectors is failing at this high cycle rate?
It's painful but swapping injectors left to right and looking for the lean code to shift would isolate.

[4-cam]

I pulled all the plugs and they looked all the same so I don't feel its one or two injectors. I think I would see the difference in spark plug colors.

Interesting thought, could i be hitting the rev limiter. When it shuts off the fuel do you get a lean code?

Corey did bump up the rev limiter when he programed my prom and last year with the old injectors i did not have this problem. Could be my old injectors were failing and adding more fuel?