Came close to melting it down...

Mike T

Well-Known Member
Joined
May 3, 2013
Made a pass at the track last night, all felt and sounded normal. Was in line for round 2 reviewing the log file and discovered that there was no fuel pressure rise during the first pass (went really lean).

Early indications are that the fuel pressure regulator stuck during the burn out. All hoses were intact and zip tied.

While driving the car home I slowly rolled into the throttle several time and rise was back to normal.

Another reminder of how the simplest stuff could take you down.



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110 Sunoco. At least going stoich at 32 pounds tells me the injectors are flow matched.....
 
Made a pass at the track last night, all felt and sounded normal. Was in line for round 2 reviewing the log file and discovered that there was no fuel pressure rise during the first pass (went really lean).

Early indications are that the fuel pressure regulator stuck during the burn out. All hoses were intact and zip tied.

While driving the car home I slowly rolled into the throttle several time and rise was back to normal.

Another reminder of how the simplest stuff could take you down.



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i would go through the fuel system and check the plugs etc.they lay over when they dont have enough fuel.mike i look at fuel pressure in real time in my car its one of the most important things inmo.you caught it in the log you can see it in the slip usually but its after the fact,the gauge will show the drop off right away.just food for thought.
 
It definitely didn't fall over but I can tell you there is NO power there.
 
Plugs all look decent and borescope shows nice sharp edges on all 6 pistons. Got darn lucky
 
I'd disconnect your FPR signal line at the vacuum block and blow compressed air though it 'backwards'.

I've heard of two instances where a rust flake acted as a check valve on the FPR. It'd act right at cruise, but a rapid boost rise would deprive the regulator diaphragm of a boost signal.
 
I'd disconnect your FPR signal line at the vacuum block and blow compressed air though it 'backwards'.

I've heard of two instances where a rust flake acted as a check valve on the FPR. It'd act right at cruise, but a rapid boost rise would deprive the regulator diaphragm of a boost signal.


Excellent suggestion Earl.
 
The fuel pressure protection in the ECUGN would've shut that baby down and given you a fault code to let you know what happened.
 
good work.compression test?

Not yet. Should have though.

This is my every day grocery getter so I've put about 75-80 miles on it since last night. There's absolutely no change in drivability so far.
 
Looks like the fuel pump to me. Pressure is dropping. Boost is creeping up too. You have a couple things going on there.

What fuel pump you running? Whatever it is it can't keep up with that kind of boost.

And what wastegate?

Rick
 
Rick the pump is an aeromotive 340 (hot wired) with 13.7 volts confirmed power to it. The pump has about 5k on it.
Regulator is a accufab that's approximately 8-10 years old.
THDP pipe with internal gate, H/D actuator, WG solenoid set to 75% through Maft pro.

I see the boost creeping up but in all of my most recent logs this doesn't happen, should say in the lower to mid 20 pound boost range it doesn't . Was thinking it could be the by product of the excessive heat energy due to the unusually lean condition....guessing.

Could be the pump but on every single 20-22 pound pull since the problem pressure will go right to 65 pounds and maintain.
 
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