Weird no-start/fuel problem

[Tyeler18]

Ok to start off: 1990 Talon AWD TSI, MBC, Boost gauge (t'ed off at the vacuum line for the stock FPR) Basically all stock other than that.

Bought the car none running because it wasn't getting fuel. Previous owner rewired the fuel pump when he replaced it with an bosch OEM replacement and it wouldn't start after that. I redid the rewire the way the VFAQ says to do it and at the relay it gets 10v, but doesn't kick on the fuel pump, so I wired it to a switch to the battery and it gets 13v to the relay and DOES turn on the pump. It has fuel up to the fuel rail (taking off the FPR it will start to run out after 5-6 seconds of the pump being on), it has spark and compression (compression was real low at 105-110 across the board, but it will start/run for a few seconds on starter fluid).

With the key "on" each terminal on each injector pigtail gets about 14v (have a battery charger on the battery) and about 2.5v when bridging the voltmeter between the two terminals and cranking. I pulled the fuel rail off, hooked it up with the injectors facing upwards towards the hood and tried cranking the car and they won't spray. Tried a different set and they do the same thing. All the injectors ohm out at about 2.9 ohms and I've tried 2 different OEM fuel rails, and 3 different OEM FPR and nothings getting them to spray.

I've spent the past week searching and have had search overload. ECU is an eprom that has been recapped in 05 and shows ZERO signs of leaking or burning. I've been checking voltage on ECU pins, but I've read so many threads on which to check that I can't even remember what I'm checking anymore.

Any help?

 

[crash89]

How about a fuel filter? Have you tried a new one? The fuel pressure dieing off tell me it could be a bad FPR, but you said youve tried a couple different ones. What about maybe a new pump? Also your compression is really low. That deffinately isnt helping much, but still doesnt fix the part about the injectors not spraying.. Im just throwing out ideas, hope some maybe be helpful..

 

[Tyeler18]

Fuel filter is supposedly new with the fuel pump, and it looks new as well. When I take the banjo bolt off the fuel filter and kick the pump on it pumps out pretty good. I need to get a pressure gauge on it to figure out whether or not I'm getting good pressure. The low compression I believe is partially the headgasket which and the fact that it was sitting for 2 months before I got it, and it was done on a cold motor. Granted I don't expect it to increase much once I get it running.

When I pull off the FPR should there be fuel in fuel rail? I can watch it seem to recede back into the fuel rail when I pull the FPR off.

Edit: I was just reading a post by Steve saying that if the TPS has a problem it can cause a no start because it may think it's at WOT. My TPS plug is all hacked up from the previous owner and I don't think it's even hooked up at all. Problem? My 95 would start without the TPS hooked up...

Alright, just to add more info to this thread. Boost guage goes to 0, CEL turns off at 5-6 seconds.

I'm starting to think it's something in the pressure to the fuel rail. How exactly do I test to make sure I'm getting fuel to the return line on the rail? If I kick the fuel pump on I can hear gas moving through the lines, but if I remove the FPR while the fuel pumps on the fuel rail is dry until about 5-10 seconds later when fuel will start running out of the end. Bad FPR maybe? I've tried the 3 different ones, but they've all been used before, so I can't judge whether or not they are good.

Turning off the fuel pump with the FPR removed causes the fuel to go back down the rail and emtpy. As far as I know it shouldn't bleed off like that, but someone correct me if I'm wrong.

I've got both the Haynes and Chilton manuals and I'll be doing some digging through them next, but the forums usually have the best results when it comes to stuff like this.

Update #3: Noid lights flash on all 4 harnesses when cranking. Got it to run for about 20 seconds on starter fluid, but I can't verify if the rail has gas in it when cranking, it seems to empty when the keys turned off and i can't verify that it gets fuel back into the rail while cranking.

 

[Tyeler18]

Update #4: Removed the CAS and spun it (taking into account where it was at). Sounds as though the injectors are clicking (will make sure), from where I'm at in the engine bay it also sounds like the MPI relay is clicking.

Weird thing is the IAC (ISC) clicks like crazy every time I spin the CAS. I'm running out of ideas on what it could be.

Narrowed it down to- FPR (unlikely), not enough fuel pressure (bought a pressure tester, just unsure yet if it will work) and I know I'm getting some fuel pressure.

Last night we wired the injectors to a 9v battery with the rail off the car. We filled the rail with gas and plugged both sides and pulsed each injector. Each one sprayed pretty far, so we're ruling out the injectors being bad (they also ohm out right at 2.6ohms) and the noid light lit up on all 4, so I know they're getting a pulse.

The only thing left really is that fuel isn't getting into the rail, I can still take the fuel line off the rail and make fuel run out, so I know it's making it to the rail, but it's like it's not staying in the rail when I go to crank the car.

Any ideas? This has me stumped, but I'm going to be checking the fuel pump o-ring for damage. I can blow into the fuel return line, so that isn't clogged.

Ok summary for anyone that is actually reading this:

1. Compression- 105-110 across the board.
2. Spark- Good.
3. Fuel- There IS fuel getting into the rail, however, unsure the pressure.
4. Noid light flashes in all 4 injector harnesses when cranking.
5. Turning CAS by hand makes injectors click.
6. Fuel pump (rewired) primes when given a 12v switched power, or when wired correctly like the VFAQ has.
7. Wiring the injectors up to a 9v battery sprays fuel into the cylinder.

Problem- Cylinders are still dry when cranking. If I wasn't getting enough fuel pressure wouldn't hooking up a 9v battery prevent the injector from spraying? Also, no fuel comes out when cranking if I pull the return line off the FPR (should it?), if I remove the vacuum hose and the return line- nothing comes out (should it?), if i remove just the vacuum hose I don't believe anything comes out. If my understanding of the stock FPR is correct shouldn't fuel come out of the return nipple on the FPR when the vacuum line is connected? Or do I have that backwards? I can pull the FPR off and fuel will pour out, but not until about 5 seconds after removing it.

When turning the key off I'm losing pressure in the line very quickly, which leads me to believe the previous owner installed the new fuel pump wrong (new fuel filter is on) and forgot/broke the o-ring, either that or the check ball in the line is malfunctioning. From what I've read though is that the car should still run, it will just take longer to start if either of the previous occur. Someone correct me if I'm wrong. I've tried 3 used FPR's and find it hard to believe that all 3 are bad, but I don't think a bad FPR would stop fuel from spraying.

 

[Tyeler18]

Newest update: Removed the fuel pump and pulled the pump itself out. Looking at the installation the white cap is missing from the pump top. I've got the bottom black brown spacer, the oring, but not cap on the top. I know this can cause a fuel pressure loss, but my talon doesn't even try to start, it just cranks and cranks with no indication of trying to start. Opinions?

Now I've got to find one of those damn spacers......


Fixed! Wally fixed her all up. The spacer is leaking, so we threw in my friends walbro 255 full assembly.

 

[nsrmotorsports]

Newest update: Removed the fuel pump and pulled the pump itself out. Looking at the installation the white cap is missing from the pump top. I've got the bottom black brown spacer, the oring, but not cap on the top. I know this can cause a fuel pressure loss, but my talon doesn't even try to start, it just cranks and cranks with no indication of trying to start. Opinions?

Now I've got to find one of those damn spacers......


Fixed! Wally fixed her all up. The spacer is leaking, so we threw in my friends walbro 255 full assembly.

hey this sounds a lot like my problem i have with my 2g awd. I've checked everything but dropping the tank and checking the pump. for you, did you just replace the pump with the wally and it started fine?

 

[Tyeler18]

Yep, we found out that the spacers on the fuel pump (o-ring,retainer cap, and spacer) had not been installed correctly. The problem was that the retainer cap wasn't even installed on the pump, so we bought a cap, threw it on and it fired right up. This was after putting my friends entire fuel pump assembly (with wally 255) in the car. When his assembly started the car we knew it was fuel pump.

We had fuel going up to the rail, just not enough. It may look like a lot of fuel is making it to the rail, but for me it wasn't enough.

 

[crash89]

Good to hear man!!