Someone please explain what is going on with this car.

90 HF crx with LS swap.

Adjustable FPR
and "on fuel filter" fuel pressure gauge

The car started running like crap a few days ago on stock fuel pressure.

Bucking really hard and just unstable.

Got a CEL codes 17(vss) & 43(i think, has to do with fuel supply right?)

anyway. So I turned the fuel pressure up untill it started running right.

With fuel pressure at 60 PSI it runs perfect. But at normal (25-30) it hardly idles and starts throwing codes.

 

43
Accord Civic CRV CRX Del Sol Odyssey Prelude
90-95 92-95 n/a n/a 93-95 95 90-95 Fuel Supply System
defective or malfunctioning fuel supply system

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18cDelSlo &raquo;</TD></TR><TR><TD CLASS="quote">Someone please explain what is going on with this car.

90 HF crx with LS swap.

Adjustable FPR
and "on fuel filter" fuel pressure gauge

The car started running like crap a few days ago on stock fuel pressure.

Bucking really hard and just unstable.

Got a CEL codes 17(vss) & 43(i think, has to do with fuel supply right?)

anyway. So I turned the fuel pressure up untill it started running right.

With fuel pressure at 60 PSI it runs perfect. But at normal (25-30) it hardly idles and starts throwing codes. </TD></TR></TABLE>

Um....change your filter and go from there. Its not complicated.

 

already done that


list of things changed:

fuel filter
fuel pump
fuel rail
injectors
distributor
fuel lines
even tried a stock fpr (wouldn't start car)
all timing components
ecu
probably some more stuff but can't think of any right now

 

Main fuel relay, its real common in DA integras

 

I'll try that... but will it be the crx relay? and where would it be at on this car? i'm more of an eg guy myself.

 

I just had some bucking/idle problems that turned out to be the fitv, but this wouldnt explain why increasing your fuel pressure made it better, or the codes.

good luck

 

it's weird, increasing fuel pressure makes it feel perfect. I'm gonna try that relay as soon as I can locate it

 

If you figure it out let me know. My fiend just put an ls swap in his 4 door,and we are having the same problem.

 

I was under the impression that stock fuel pressure was higher than 25-30 psi. I thought over 40psi to be perfectly honest.

interesting that the code is still being thrown, there aren't that many things along the fuel system that plug in and would cause that code to come up...

did you try a set of cleaned and balanced injectors or just a handful out of another motor or off the workbench?

they might be dirty and causing a light spray pattern, hence why increasing the pressure makes them squirt enough past the blockage.

just a thought

 

Yes I agree I thought stock pressure was 36 to 40 psi somewhere around there.

 

ok well the relay checked good... Maybe it's this crappy fuel pressure gauge on the fuel filter (it's a no name brand i think, was on it when I got the car...) I will try use anthoer gauge to see what the fp is.

Any other ideas in the mean time would be great.

 

a bad reading off the guage could be causing alot of alarm, but since you're throwing codes for the fuel system, i dont really think thats it.

 

yeah i know... Still haven't gotten the fuel pressure checked. gonna try to do it today.

And the code 17 is gone. I took out the cluster and tightened the grounds for the vss.

but the code 43 is still there. There can't be that much to this motor.

 

you're right, it shouldnt be this hard...

 

Your problem could lie in your gauge. It may be that the gauge is restricting the fuel flow to the engine and when you increase the pressure it is only allowing the normal amount of fuel.

You might want to remove the gauge and install a stock fpr. If this works look into getting a higher quallity gauge.

Good luck to you.

 

I've tried using the stock fpr and the car barely runs. It backfires, sputters, things like that.

This weekend I took off all the fuel lines and used an air compressor to blow through the lines to check for blockage, they were all clear.

However, the fuel return line seems like it has a delay, like you can stop feeding air and it takes about 3-4seconds for it to come out the other end. Is there a valve on the pump assembly or could there be something blocking the line?

 

Did you ever remove the gauge? You should at least try. It may not be your problem but you wont know unless you try.

 

Yeah i need to buy a new service bolt to replace it. Its a gauge on a bango bolt. I'll post back when I get this done.

 

I actually have a prob with my fuel as well. I got a ls vtec with stock ls block with a b16 head. I have an adjustable fuel pressure regulator silver in color no idea of the brand. I had to buy the guage separate. Its the one that goes on top of the fuel filter. For some reason I can't get the pressure to go pass 30psi. I was told that's pretty low. My car doesn't smoke or over heat. It just feel like it needs more??? I have a stock p28 which I want to chip out after I get the car running better. I tried putting in a chipped computer and I felt no difference.

 

Does your car run ok? Cause I was having to turn mine up really high to get it to run right. But i suspect the gauge is just reading wrong and i'm really ok... ha

 

well it doesn't run good. My ls vtec came with an adjustable fuel regulator. Problem was I couldn't tell what the pressure was at. So I brought the fuel pressure gauge that goes on top of the fuel filter. Funny thing is the pressure won't go pass 30psi which is low by the way. For a DOHC vtec motor it should be at least 40psi. I even tried putting on a stock gsr fuel regulator and it reads 30psi also. When I get on the throttle the car makes this big bogging noise likes it's sucking too much air but doesn't really move. If I gradually give it throttle it moves better. Did you ever change that gauge on top of your fuel filter. I wonder if its possible that it resisters how much fuel you dump

 

quickwitit, check your ignition timing. You can get a craftsman timing light for like $20. Or barrow one from someone.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by im a joke &raquo;</TD></TR><TR><TD CLASS="quote">Yes I agree I thought stock pressure was 36 to 40 psi somewhere around there.</TD></TR></TABLE>

Stock fuel pressure is around 36 on my cars.

 

OP: try turning your fuel pressure up to stock.

By running it at 25-30psi you are purposely starving your engine and that is probably what is throwing the code.

Stock fuel pressure for OBD0 B16 is 35-41psi in the shop manual.