enough injector?

[Vett-Klr]

I recently upgraded to 60# injectors and a GTA67 turbo. The car is missing or hesitating or something after half track. There is no KR.
With 15 # of boost it is fine and runs 12.2's. When I cranked it up to 18 PSI I ran 12.7. Am I running out of fuel? I have dual pumps and the second one is coming on. This is very frustrating, this car should be in the 10's and I can't even sniff 11's right now

 

[AKplumber]

You need some information to see where your tune is at. What are you using to log and what is it telling you. Afr, egt's, o2's, Kr, timing?

With these cars the tune is everything.

 

[johnplogii]

What are you running for fuel? And do you have a fuel pressure guage you can watch as it cuts out? I don't think you are out of injector.

 

[RUQWKNF]

Also, when was the last time you changed your factory fuel filter. If you are running double pumpers and factory lines, both pumps are trying to force all of the gas through a possibly clogged fuel filter and that will eventually lead to pump weakness and or possibly failure.

Patrick

 

[Blazer406]

60's are plenty for mid 10's easy.... you have an issue elsewhere. Like Pat said....check fuel filter....

What plug gap are you running?

Are you datalogging the run? This would definately help troubleshoot the problem.

 

[Vett-Klr]

Other than a scanmaster, no datalogging.
The plugs are gapped at .025
The O2 counts were in the low 800's
I was running a 50/50 mix of 110 and 93
There was no KR at all

At 15 PSI there was no problem, but at 18PSI it was hesitating at the top of second gear. I got off it and ran 12.7 @99 with a 2.6 60 foot.
At 15 PSI it runs low 12's@115.

When it hesitates, there is no noise/backfire, etc...just a hesitation, almost like I'm sitting on the rev limiter.

 

[UNDER-PRESSURE]

Why are you running the plug gap that tight?

 

[86BLACKT]

I had a bad o2 sensor that made me run really fat causing car to be a pig. millivolts on scan master were a little lean, and I kept adding pressure. Replaced o2, lowered pressure, and hang on!!

 

[Vett-Klr]

Why are you running the plug gap that tight?

To avoid the spark to be blown out

 

[UNDER-PRESSURE]

To avoid the spark to be blown out

How do the plugs look? Are they firing OK, fouled? Have your tried running the gap at .35?

 

[RUQWKNF]

Well for one, I agree with UNDER PRESSURE, you don't need to have the plugs gapped so tight, .032 - .035 should be fine on stock ignition until you get over 28psi. No matter the turbo. I still feel like something is up with your fuel system. Have you done the flow test the old fashion way? Timing how long it takes to fill up 1 gallon with both pumps on and fuel pressure manually raised to say 61 - 62 psi?
Do you have a fuel pressure gauge you could put under the windshield wiper and monitor while making a run? With 43.5psi static at idle set with the hose off, then making sure to re-install the hose naturally and 18psi, you should have a rock steady 61.5 - 62psi when both pumps are going. Also, have you verified your battery voltage when both pumps are running under WOT? That could possibly affect the flow for sure. With the car running 115 mph with only 15psi of boost, it is making some good power. Any idea what your O2 numbers are at the end of a run?
We need more info to better help. But I can assure you, if you haven't changed your factory fuel filter in over 10-20k miles (located underneath the drivers door and in front of the drivers side rear tire for all the newbies out there tuning in) it's gotta be clogged or at least partially clogged.
Is this a street chip or a race chip? Whose chip?
Let us know as we are all here to help.

Patrick

 

[Vett-Klr]

Well for one, I agree with UNDER PRESSURE, you don't need to have the plugs gapped so tight, .032 - .035 should be fine on stock ignition until you get over 28psi. No matter the turbo.

OK,I'll got with .032

Do you have a fuel pressure gauge you could put under the windshield wiper and monitor while making a run?[/B] With 43.5psi static at idle set with the hose off, then making sure to re-install the hose naturally and 18psi, you should have a rock steady 61.5 - 62psi when both pumps are going.

I do have a fuel gauge, the pressure is set at 45 static, goes down to about 42 with the hose back on, and mid 60's under WOT. I'll assume that if I am getting 65PSI at the fuel rail, my filter is ok??

With the car running 115 mph with only 15psi of boost, it is making some good power. Any idea what your O2 numbers are at the end of a run?
We need more info to better help. But I can assure you, if you haven't changed your factory fuel filter in over 10-20k miles (located underneath the drivers door and in front of the drivers side rear tire for all the newbies out there tuning in) it's gotta be clogged or at least partially clogged.
Is this a street chip or a race chip? Whose chip?
Let us know as we are all here to help.

Patrick

You are right, the car is making good power and I suspect there is a 10 second pass in it if 'I can get it to run right.
The chip is a 93 octane chip from Full Throttle, I have the MAF GenII, the settings are stock except I am giving it additional fuel from 4,000 rpm up.

Help me get in the 10's!!

 

[86BLACKT]

As Patrick said...street or race chip. My street chip kills the car at 85mph. I ran 12.01 at 102. The car shut down at 3/4 track.

 

[bison]

OK,I'll got with .032


I do have a fuel gauge, the pressure is set at 45 static, goes down to about 42 with the hose back on, and mid 60's under WOT. I'll assume that if I am getting 65PSI at the fuel rail, my filter is ok??



You are right, the car is making good power and I suspect there is a 10 second pass in it if 'I can get it to run right.
The chip is a 93 octane chip from Full Throttle, I have the MAF GenII, the settings are stock except I am giving it additional fuel from 4,000 rpm up.

Help me get in the 10's!!

You have to be sure your ignition is up to par. Sounds like it isnt. Maybe some grounding issues. Your overfueling if your static pressure is 45 and you are running 15 psi boost and 65 psi. It should be 1:1. You would be better off with a datalogging wide band setup. Much easier to get a real accurate a/f.
number.