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1G Not holding fuel pressure

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AWD-Tony

Proven Member
6,801
3,735
Sep 11, 2017
Cincinnati, Ohio
Before today, fuel pressure would hold for at least 30 minutes when car is off.

I swapped out my injectors to Bosch 2200. I removed the resistor pack and wanted to make sure there’s no leaks. I hear the pump prime but I’m not getting pressure reading on my afpr. I plugged the resistor pack back in and still nothing. Bosch injectors are high z and I’m waiting for depin tool so I can combine those wires. What am I missing? I should still see pressure as long as I hear the pump, correct?
 
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It sounds like the injectors are bleeding down. I have had some that bleed fast and some that will hold pressure into the next day. My stockers are holding for a few hrs just like your old injectors did for reference. But yet you say cylinders are dry....puzzling.
 
It sounds like the injectors are bleeding down. I have had some that bleed fast and some that will hold pressure into the next day. My stockers are holding for a few hrs just like your old injectors did for reference. But yet you say cylinders are dry....puzzling.

Yeah. Checked all 4. I’m so confused. It’s def not the injectors. It would be a crazy coincidence that the check valve on my pump took a crap today.
 
What exactly have you done to the car? You pulled the old injectors and installed the new and that's it? You said you removed the injector resistor pack but remember that's what supplies 12v power to the injectors.
 
What exactly have you done to the car? You pulled the old injectors and installed the new and that's it? You said you removed the injector resistor pack but remember that's what supplies 12v power to the injectors.

Right. I’m not trying to start it. Only checking for leaks. And yes only thing was replace the injectors since I sold the ones that were on the car. Right now I have the tcase, downpipe and resistor pack off
 
i never had an issue with pressure drop until after i went to the cell/ external pump. mine held for ever on the 255 and 450 pumps. never noticed an issue either when i went to a bosch injector either.
 
Just thinking out loud here, Are there more than three places the fuel system can leak and not make a noticeable mess?

In the tank, before or after the check valve.
Via the injectors, you'd see fuel in the cylinders.
Via the FPR, either out the return back to the tank or past the diaphram and out the vacuum line.

Can you think of others?
The two in the engine bay are easy to test for, sadly the pump end you just have to pull and doing so might fix the problem before you noticed.
 
Far right plug is covered in fuel. But nothing before firing the injectors
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Can someone confirm If the intake valves in that cylinder were closed when I primed the pump before turning over the engine, I wouldn’t see or smell fuel when I removed the plugs? That’s the only thing I can think of as to why I didn’t see or smell fuel prior to start it.
 
Can someone confirm If the intake valves in that cylinder were closed when I primed the pump before turning over the engine, I wouldn’t see or smell fuel when I removed the plugs? That’s the only thing I can think of as to why I didn’t see or smell fuel prior to start it.
if the intake valves are closed before you cranked the engine over they should seal against the seats not letting fuel get by therefore you wouldnt/ shouldnt smell it.
 
Just thinking out loud here, Are there more than three places the fuel system can leak and not make a noticeable mess?

In the tank, before or after the check valve.
Via the injectors, you'd see fuel in the cylinders.
Via the FPR, either out the return back to the tank or past the diaphram and out the vacuum line.

Can you think of others?
The two in the engine bay are easy to test for, sadly the pump end you just have to pull and doing so might fix the problem before you noticed.

I’m thinking that injector is stuck open and the intake valves were closed. That’s the only thing that makes sense.
 
if the intake valves are closed before you cranked the engine over they should seal against the seats not letting fuel get by therefore you wouldnt/ shouldnt smell it.

I’m convinced it’s from that one injector. Thank everyone for the input!!
 
yea if that injector is stuck open that would defiently make sense. id double check your oil now just to be safe.

I will. Not driving it any time soon. Have to find a trans noise and probably grab another wb sensor. This has snowballed out of control
 
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