Car suddenly not wanting to start

BrianG

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Alright 3800 gurus, I'm gonna dump a ton of info here about the problem I'm having, and any suggestions you've got are much appreciated. The problem is that the car is cranking very strong, but never starts, never even sputters. [MENTION=750]RICH17[/MENTION] and I have pretty much narrowed it down to the injectors not firing, but I have no idea why they wouldn't. I did just have the motor and trans out, but didn't change anything except some power and ground routing. Here's what I'm seeing:
Checked spark on 2 front cylinders: good
Fuel pump primes when key is turned, and for 2 seconds after starting attempt
There is pressure going into the PRJ FPR
New fuel
SES light comes on and stays on with key in ON position (verifies PCM grounded?)
PCM responds to HP Tuners (have pushed and pulled my current tune)
RPM responsive in HP Tuners on start attempt
MAF responsive in HP Tuners on start attempt (did not verify value, just saw it changing)
MAP responsive in HP Tuners on start attempt
O2 responsive in HP Tuners on start attempt
Replaced ICM and PCM, no change

The orientation of the PRJ FPR has changed, but it uses a stock Bosch style FPR in it, and from what I understand, it's orientation should have no impact.

I'm at a complete loss here, and I don't know what the hell could have suddenly caused it to not start. It ran perfectly before everything was pulled, and now I've suddenly got issues. Any ideas are appreciated. I have yet to unplug the MAF and try to start it, which is probably a long shot, but an easy and free diagnosis. If you have any other questions about the setup or diagnosis that have been performed, ask away!
 

SleeperLS

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Isn't there a cam or crank position sensor that is a bitch to get to? That plugged in? I remember forgetting to do that once and the car wouldn't start.
 

RICH17

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Front cover area was never unplugged when the motor came out. Harness comes with it. Unless they went bad in the year that it sat
 

SleeperLS

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Yup, that is the one. I would just double check that it is seated all the way. Really, I hate this type of shit. It happened to me twice when I pulled my motor. Once was that dumb sensor and the other time was a wire harness connector got tugged on too much and one of the wires was busted under the wire loom. That was a bitch to trouble shoot because it wasn't obvious until I took down all the loom.
 

BrianG

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I did check that the crank sensor is plugged in all the way last night. Also, I wouldn't get an RPM reading if that wasn't plugged in, right?
 

b4black

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If you think the injectors are not firing, check the leads with a multimeter. I believe they have power all the time on one wire and the other is grounded to make it fire.

Or Google "noid light".
 

BrianG

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If you think the injectors are not firing, check the leads with a multimeter. I believe they have power all the time on one wire and the other is grounded to make it fire.

Or Google "noid light".
Yeah, that's the next plan. I've been seeing "noid light" all over the place in my searches. I do believe you are correct about the injectors too. The PCM sends a ground pulse to get them to fire.
 

boostedguy05

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"The orientation of the PRJ FPR has changed, but it uses a stock Bosch style FPR in it, and from what I understand, it's orientation should have no impact.
"

tried going back to original orientation?
 

BrianG

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"The orientation of the PRJ FPR has changed, but it uses a stock Bosch style FPR in it, and from what I understand, it's orientation should have no impact.
"

tried going back to original orientation?
Not yet, but it's on the list of long shots to try.
 

boostedguy05

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start with what has been changed and go from there.

hope you get this figured out fast.
 

b4black

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"The orientation of the PRJ FPR has changed, but it uses a stock Bosch style FPR in it, and from what I understand, it's orientation should have no impact.
"

tried going back to original orientation?
Connect a fuel pressure gauge to the rail. If the pressure builds at key on and maintains during cranking, then it's not a fuel issue.

Great tool to have:
Fuel Pressure Tester & Fuel Injection Pump Tester
 

RICH17

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NOID test came back up good. Unplugging MAF didnt do anything either. FUCK
 

boostedguy05

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Edit : read other thread where rich said you checked all plugs for spark. And would be checking maf tonight.
 

BrianG

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Okay, here's the latest. I'm fuggin lost...
Plugged in noid light (2 different injectors). Results: light off at key on, starts to blink during cranking.
Checked for continuity on ICM ground in connector to ring terminal and all over engine bay: good.
Pulled plug again and checked it, looks fine.
Disconnected MAF, no change.
Double checked that crank and cam position sensors are plugged in tight.

I've followed the "crank but no start" diagnosis steps in the manual and the ONLY step that I've not explicitly performed is checking the actual fuel pressure value because I don't have a Schrader valve to connect a gauge to. I did find out last night that my PRJ fuel pressure regulator adapter has a port in it for a gauge tho, and I'm trying to locate one for that, so I can close that diagnosis out. I know that I'm getting fuel TO the FPR because we pulled the line off and hot wired the pump to empty the tank of year-old gas. I'm losing my mind over this.

Because I have at least some pressure at the FPR, doesn't this mean that it would either have to be all 6 injectors bad/clogged or the FPR just not flowing fuel?! What else could it possibly be!?
 

Turbocharged400sbc

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is the hose at the fuel pump in the tank rubber or is it the corrugated plastic maybe you blew it and you're getting just a little bit of pressure but not enough
 

BrianG

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Nothing is leaking. Should I expect leaking (to the floor) in that case? From the tank to the filter is braided stainless. From the filter to the engine bay is stock steel. From the engine bay to the rails is braided stainless.

Even if the pressure was low, wouldn't the injectors still put fuel in the cylinders and give me at least some chugging?
 

BrianG

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One thing I seemed to notice is that I don't get a MAF DTC when it is unplugged. I don't know if I should expect one right away or if it takes several starts or cycles, but I got a TPS DTC right away when I unplugged it during my testing.
 

BrianG

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Hose in tank. Pump to tank sending unit
Oh, I have no idea then. I would think/hope that's not bad. I THINK the sending unit was replaced probably 5 years ago when the Walbro 255 was installed during the swap project. I guess I have no way of knowing if that hose is bad without dropping the tank. The pump seemed to flow well enough when we were emptying the tank, but I suppose that could be a completely different story when it's trying to build pressure while pumping. Again tho, wouldn't I at least get some chugging and SOME firing, even if shitty?
 

10sec

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You have changed things, you must reverse the changes until you figure out the problem. That is how you will fix your vehicle.
 

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