My last thread was too long and it concluded a problem with the fuel pressure regulator.

Recently...



Tested Fuel pressure, 100+ psi. Regulator isn't opening at all, half the time my gauge blows right off the line.

So I used this screwdriver to try and force what I believe is the fuel pressure regulator into some kind of response.



I don't understand if that box (what I believe is the Fuel Pressure Regulator) makes vacuum or depends on it.

Let me know guys, thanks.

 

that's not the FPR...
I believe that is for the variable intake runners.
not too sure, it's only a VG

 

The part arrowed in the pic is the fpr...The part you are messing with is the power valve actuator,it has nothing to do with the starting of the car..

I am going to recommend you take this car to a qualified mechanic for further diagnostics...

 

Whoa, you have put the t connector and left the filter out of the circuit. !!

Connect the incoming fuel hose to the fuel filter, go buy a small piece of fuel injector hose (5/16 th I believe) and then connect the out of the fuel filter to the t connector. Also clamp ALL hose connections before switching on the car , unless you like spraying your engine with fuel and setting it on fire. then measure presure.

But, seriously, given what you have posted, a good mechanic or a friend who knows stuff is your best bet.

And you need a new fuel filter.

 

anybody have the regulator for sale?

running it without a filter for 20 seconds isn't going to do anything.

 

Yea I have one. You want it shipped or meet me some where? PM me.

~Alex

 

Your FPR is connected to your fuel rail. Two screws.Very uncomfortable removing. Unless you take the whole top off up till the fuel rail.

 

holy rust, man. get a new PCV valve while you're at it. that thing is probably as old as the car. It's like 3 bucks fifty, not a big deal for something like that. but i'll second the notion to get proper clamps on everything to quit from dousing the car in gasoline. I thought i was a deadman when i changed my fuel filter... still had about 10psi in it (even after 5 start-stalls with a pulled FP fuse...) and gas shot out the top while my engine was still partially warm.

 

WRONG !! it takes only a few seconds for some piece of crap to go from your fuel tank to blocking up your injectors. Then you should plan on a $1000 repair, since you dont seem able to do the job yourself and even then at least $600.

 

Me thinks that was mygreenmax's old photo/parts car

 

heh oops. even so, the power valve acutator and everything near it on plaman's car is totally rusty too. I just failed to notice where plaman's post ended and wayne's began. I wouldn't want to drive that car with all that rust down there... who knows where else the rust may be? control arm? parallel links? tie rods? I'll take my squishy LCA bushings over a rusted-out suspension anyday. the only rust on my car is a tiny bit on the fuel door and a bunch on the brake booster from when the previous owner had a master cylinder go bad and leaked fluid onto the booster, and then my top radiator mounts are kinda rusty too.

 

Update: I finally got those stubborn screws off the regulator and the regulator out and shoved some compressed air into it, made a "honk" noise the first two shots then stopped and just blew out air, now its reading 80psi but it still won't start, I planned on getting another FPR anyways. Progress I guess.

 

Alright, finally replaced the regulator with a brand new one from advanced auto. Pressure still blows off the gauge, are regulators like thermostats and often times don't always work the first one you buy? If not I'm really thinking its finally come down to the ecu or the computer.

 

New regulator and still see way more than 45psi? ................. plumbing gone for a loop? - either wrong connections/routes or a blockage or you really have a crappy new regulator.

Sort this mechanical issue first before you start fiddling with the ECU - the ECU cannot possibly improve/cure this problem.

 

+1, I can't figure out why one would do that. You already have to source a t-fitting (also, those are not proper fuel injection hose clamps) how hard is it to spend the $2 on a short length of hose?

 

It's begging to sound like a tubing problem after the regulator. Take off the hoses to and from the fuel rail and make sure that you can blow air (not high pressure, just lightly) through the disconnected fuel rail and then through the pipe after the regulator back to the fuel tank. Perhaps you have a clogged, bent or crushed fuel return line.

 

What he said

 

I second or third the fuel line clog. You should NOT be reading anywhere near 80-100 lbs pressure! You should be running about 35lbs.

Stop what you are doing and get the car to a mechanic!

 

Doesn't it peak at 65 when @ WOT?

 

Nope, it should be at a max of approx 42 psi at idle or with the vaccum tube pulled and drop to 32-35 when the throttle is opened. The pressure stays the same , the flow increases with speed.

 

I'll try blowing the fuel rail out and check the return line too. Meanwhile keep praying its just a lousy regulator.

 

Go buy 7 feet of fuel injector hose and a 5 gallon fuel can. Connect the hose to the fuel pressure regulator and put the open end in to the fuel can (properly grounded. Have a friend start the engine and check the pressure (very short time). If its good, then its your return line. Otherwise its the could be your fuel pressure regulator or a clog in the fuel rail ( not using a fuel filter during testing could be expensive). You will have to check both.

 

sounds good, i'll try that tomorrow.

 

the latest, looks to be a clog in the fuel rail, any good FAQs for tearing down into it or anything i should look at replacing while im in there?

 

also can i check an injector to determine good/bad?

 

Recipe to check an individual injectorYou need to find an answer as to how, whatever it is that is cuasing the "block", got into the rails in the first place

 

This ones easy, he tested his fuel pressure without the fuel filter in the circuit. He got some crap from the tank into the fuel rail.

 

but it wasn't starting before i even messed with the fuel pressure test, why else would i check pressure or do any of this if it ran fine? and the pump has a fairly fine screen for filtration, nothing big enough to clog the fuel rail would fit. im looking at the old owner/mechanic who had it.

 

I assume you started with easiest to fix first before diving into a fuel problem. 90% percent of the time the problem is not fuel.

 

dont we also have a intank fuel pressure reg on the pump.. I know i just installed a new pump in my 91 and it has a built in pressure relief valve built in it. It was very expensive. i found one new on ebay for 60 clams

 

If it is present in the tank (?) it is there for pump safety/protection - not engine mangement. The FPR on the injector rails is the one to speak to when pressures are too high.