New FPR issues...

[BlueVelocity]

First a bit of background from the past week..

I did the fuel pump re-wire, 8 guage, 30amp relay. This increased my pressure to over 50 psi. I went and bought a brand new Aeromotive 13109, also known as the A-1000. 40-70psi model. Without the vacuum line attached, it's rock steady, sets just fine. When I connect the vac line, it wanders. It's at 40, then 35, then 40, then 25, then 35, and so on. Not in any specific pattern, just random. Check the fuel pump voltage, 13.78 and rock steady with the car running. Both the EVC and the Westach boost guages read steady 12 inches of vacuum, normal. Replaced the vac line that leads from the manifold to the FPR thinking it had a small hole. Nada change. Same symptoms. This seems to be giving me random fuel cut, but from what I can see, base at 40, boost seems to rise it up to about 60 which seems fine. Any ideas here fellas? It's even giving me part throttle fuel cut on occasion too.

Erron S.

[Kibo]

Have you checked for a vacuum/boost leak at the adjustment screw threads on the FPR? You might also want to put some thread compound on the hose nipple threads as well.

[BlueVelocity]

Have you checked for a vacuum/boost leak at the adjustment screw threads on the FPR? You might also want to put some thread compound on the hose nipple threads as well.

No, I haven't checked to see if it's leaking, but I did put teflon tape on it when I got it. Maybe I didn't put enough?

Erron S.

[Carl Morris]

I'm no FPR expert but I'd suspect a sticky/defective regulator and be taking steps to request a replacement.

[dsm_gsx97]

You can borrow mine too since the car won't run till this weekend now. I'm thinking like Erik and that there is something not sealing, but I have mine you can double check with. Since I'm meeting Shawn tomorrow to give him a tranny to send to Shep, I'll inlcude my Aeromotive for you to check out if you still need it. Or make Shawn lend you his for double checking now that I think about it since he's right around the corner. :D

[BlueVelocity]

You can borrow mine too since the car won't run till this weekend now. I'm thinking like Erik and that there is something not sealing, but I have mine you can double check with. Since I'm meeting Shawn tomorrow to give him a tranny to send to Shep, I'll inlcude my Aeromotive for you to check out if you still need it. Or make Shawn lend you his for double checking now that I think about it since he's right around the corner. :D

We're going to pull it apart tonight and have a look-see. Hopefully, it's just a pinched diaphram or something silly. Shawn said he would be here around 5:15 if you want to stop by and supervise. :D

Erron S.

[dsm_gsx97]

We're going to pull it apart tonight and have a look-see. Hopefully, it's just a pinched diaphram or something silly. Shawn said he would be here around 5:15 if you want to stop by and supervise. :D

Erron S.

We'll have to see...I was going to be driving home right by there, but Kenny wants me to go down to 9 second tonight after work to see him. Since I was living in the garage for 2 weeks working on the car I have to clear everything through the wife before I end up in the garage for good now that I dont' have races to get ready for.

[BlueVelocity]

We'll have to see...I was going to be driving home right by there, but Kenny wants me to go down to 9 second tonight after work to see him. Since I was living in the garage for 2 weeks working on the car I have to clear everything through the wife before I end up in the garage for good now that I dont' have races to get ready for.

I know the feeling. It's a fine balance..

Erron S.

[DSMtuned]

Erron,

I'll be interested in hearing what you find. I actually just installed a the same regulator (A1000), brand new from Summit Racing. I've been having the same problem. FP is all over the place at idle, but exactly where it is supposed to be boost.

I don't think it is a torn or damaged diaphram because the regulator that I replaced with this new one, had a torn diaphram. This resulted in the upper part of the regulator being filled with gas which was forced out of the adjustment screw and also into the vaccum hoses. The regulator controlled fuel pressure correctly, though.

For my car, I was wondering if it is an ECU issue since I still have the FP solenoid hooked up.

-Craig

[BlueVelocity]

Erron,

I'll be interested in hearing what you find. I actually just installed a the same regulator (A1000), brand new from Summit Racing. I've been having the same problem. FP is all over the place at idle, but exactly where it is supposed to be boost.

I don't think it is a torn or damaged diaphram because the regulator that I replaced with this new one, had a torn diaphram. This resulted in the upper part of the regulator being filled with gas which was forced out of the adjustment screw and also into the vaccum hoses. The regulator controlled fuel pressure correctly, though.

For my car, I was wondering if it is an ECU issue since I still have the FP solenoid hooked up.

-Craig

I also still have the solenoid connected, but out of the loop now. (didn't seem to matter) Are you getting any type of fuel cut?

Erron S.

[DSMtuned]

I also still have the solenoid connected, but out of the loop now. (didn't seem to matter) Are you getting any type of fuel cut?

Erron S.

Nope, no fuel cut. The car runs great. This actually started a bit after I installed the new regulator.

It seems to happen more when the car is warming up, which is when the ecu is monkeying with FP. Once the car is hot and FP is not being screwed with, the problem is less obvious (not as noticible dips on the gauge).

[BlueVelocity]

I think it's been discovered... (I can see Hal smacking me for this one) lol

We tried everything, pressure test of the fpr, check the diaphram, made sure the pump wasn't cavitating, good 13.7 volts at the pump, etc...

After about 2 hours of Nick, Shawn, and myself pulling out our hair, we couldn't find the issue. So, just for kicks I wondered what the bleed off of the new fpr was like. I turned on the fuel pump with the datalogger without the car running and guess what? The guage was bouncing from 20-48 psi after the pump had shut down. I said that's impossible! It would take over 40 inches of vacuum to see a 20 psi drop. I then took the digital multimeter and read the voltage from the sending unit. It was all over the place. Anywhere from .162 to .189 volts, and at random! Comparing that with the guy at westach, turns out it's a faulty sending unit. Not only was it faulty, but even after having it for almost 2 years, they are sending me one for free!! Talk about customer service!

Well, you know what that means. I had no real idea as to what my fuel pressure was when I set it due to the faulty unit. I just count my blessings that fuel cut enabled itself at the import race and it didn't cost me a piston or motor. Live and learn...

Erron S.

[DSMtuned]

Hey Erron,

I'm glad you solved your problem!!

I think I have a bad sending unit also. I also have a Westach FP gauge and sender that are about 2yrs old. With the multimeter I have not been able to catch the sending unit in the act of acting up. The problem is too intermittent. I'm going to check all of my wiring connections and grounds and see if that solves it.

Thanks for the lead!

-Craig

[BlueVelocity]

You bet! Let me know if yours is doing the same thing.

Erron S.

[Kibo]

Dangit...whatever virus your sender had must have been transmitted to my car. Last time I had my SPA FP gauge installed on the Galant, it worked fine. Now that I have it installed on the 2G, it floats around with the car off. :mad: I've already replaced the sensor once before. *sigh*

[BlueVelocity]

Dangit...whatever virus your sender had must have been transmitted to my car. Last time I had my SPA FP gauge installed on the Galant, it worked fine. Now that I have it installed on the 2G, it floats around with the car off. :mad: I've already replaced the sensor once before. *sigh*

Really? You havn't had those that long have you?

Erron S.

[dsm_gsx97]

This thread brought to you by Autometer...3 years and running strong. :D

*poke* ---->


*poke* ---->

[Kibo]

Really? You havn't had those that long have you?
I've had them for 5 or 6 years, but the sensor was replaced once by SPA and it wasn't used for the last two years while it was installed in the non-running Galant.

I think my car has some phantom electrical issues, most likely with grounding. I think that could be affecting my fuel trims as well as my sensor readings. The voltmeter on my radar detector (wired directly to the fuse box) seems to wander around. For all I know, the regulator on my alternator could have issues. I just love phantom electrical problems. :rolleyes: