I just bought a 94 gsr with apparently itr cams and crank and a gsr trans w/ lsd.

It has a walbro 255 fuel pump which ive read is fine to run on stock injectors.

It has a aftermarket fpr and fuel guage.

Its running around 33-38 but its hard to tell cuz it goes up and down really fast.
Is it supposed to flicker like that?

I read it supposed to be 39-46.

So if i turn it up should this go away??

I can clearly hear it backfiring and feels like the fuel just cuts off around 3-5k rpms.

When im at wot its usually fine i can go through the rpms good and the fuel wont cut off

But when im just cruising at say 60mph at around 3k rpm it will bog.
It accelerates a tiny bit then cuts off then accelerates a tiny bit then cuts off.

I just wanna know if there could be something else wrong with it besides fuel pressure.

Right now im gonna check to see if the injectors are stock and turn the fpr up some.

Thanks in advance for any tips or answers

Edit: Checked plug gaps, .035!!! wtf is that?? could that have been my problem this whole time? I still think im lean tho.

 

backfiring is usually related to ignition timing. check the timing. also, check that the plug wires are in the correct order

 

checked plug order, it might not be back firing thats what i think it is, sounds like a drag car launching.

I was thinking maybe timing but was hoping not, It just seems like fuel to me cuz it runs fine sometimes low fuel pressure cant cause this?

Its kinda like a pop like all of a sudden it gets fuel then stops then pops a little fuel then stops.

How do i know if my injectors are stock i cant tell, they dont say any brand on them, they have some marking but im have trouble telling what it says.

 

What ecu are you using stock?

That walbro should throw a code on your stock ecu! it did on my itr.

Second you cant use a after market fpr on a stock motor and or ecu it will not run right. Use a stock one asap it might just fix your problem.

Third you dont need a aftermarket fpr unless its a full out race car! most use a stock fpr on even big hp builds!

Dont play with the fuel preasure or you will end up damaging the motor that should be done while tuning the motor.

just use standard ngk plugs for a gsr dont gap them, that too can make the motor run like ****.

check the firing order after you put a stock fpr, ecu, and fuel pump back in and start and check the timing and adjust if needed.

 

i don't see how using an aftermarket fpr on a stock setup would hurt. if it were set to stock pressure. also, there's no way for the ecm to monitor fuel pressure, so it wouldn't throw a code. not for pressure anyways. also, you ALWAYS check the gap on plugs before installing.

OP, you have a fuel pressure gauge on there?

 

Any check engine lights?

 

absolutely. regardless of a CEL, check for codes. always

 

got code 7, tps, blox tps in the mail

Heres the weird thing.

I check the tps wiring and its got some random wire spliced into it

I guess the guy was using the tps to give power to something else, and i think it may have been going to an unhooked auto meter. Also the auto meter is not connected electrically but has a vaccum line connected. Im about to remove it and loop or plug the vac line

 

Some more stuff ive found.

Has a fitv block off

Only 2 wires going into secondary O2 sensor 3 wires coming out??? ***EDIT: THIS PART ISNT TRUE***

This car is an electrical nightmare im so confused as to what this guy was doing.

The wire spliced into the tps and the wire coming out near the secondary 02 are both solid yellow. I can see where he taped the wires in to make it look semi factory so im assuming they are related but idk what they were doing??

 

It amazes me on the half *** weird **** things people do to these cars!

 

try disconnecting the o2 sensor. see if this persists. only take a second

 

some updates:

Looked through the wiring better.

The yellow wire was spliced from the tps going to a wire in the secondary o2 that was going to an auto meter.

I put everything back to stock and removed auto meter that was not hooked up electrically.

And i took the tee off the oil switch location and installed the oil switch oem style.

Havent driven it yet,

Problems:

Idles a lil high at 1k should be easy fix, just adjust the idle screw

Fuel pressure still low at idle about 32-39 deff doesnt go over 40 so i need to raise that i believe.

My temp guage doesnt work, havent looked into that yet. I do have an 00 cluster in my 94 but i double check the pin out and i know the 00-01 is diff from 98-99.

 

just disconect it and drive around? and see if thats causing it to run lean?

can i check resistance on an o2 sensor?

 

the o2 shouldn't be tee'd into. signal wire is shielded. disconnect it and drive it. see if the problem persists

 

You say its ok and the other poster says its not ok to run adjustable fpr. Ive never heard anything wrong with running one.

I still would like a stock fuel pump and fpr but id rather not pay if i dont have to.

I think the fact that the fuel pressure at idle is 32-38 and the plugs were .035 says something.

Why was he running it lean and such small gap which is basically like getting a step colder plug right? He also has rad fan hardwired to be always on, idk if theres a reason for that. Like i said it seems liek the guy just loved to mess with wires, theyre everywhere lol.

And yes like i said above but it flickers from 32 to 38. Is it supposed to move like that or stay in a general point?

 

Also can someone please tell me how to adjust my fpr or point me to a link.

It seems like such common knowledge that no one discusses it. Ive tried searching.