What are the signs of a bad fuel pressure regulator?

[stinkydogfilms]

Problems came back.
I drove a total of 310 miles since the last fix a month ago. While driving home, after about 4 miles I was at a stop light. In about a minute it felt like a surge down like it wanted to stop. I put it in neutral and revved up a little. It drove away fine.
At another light, in about a mile I just put it in neutral.
I made it home and sat with it running in drive for 10 minutes, then it started surging down again eventually cutting itself off.
It started up again and was ok in park.
In drive it would surge down again.

I just went out 8 hours later and it was really rough starting. It was sputtering upon cranking and eventually started. I revved it up in park and it cleared itself out. I cut it off and tried again, it was the same thing.
I hear the fuel pump humming loud, so I assume it's ok.
Tomorrow I will swap the old IAC back on and check the adjustment of TPS and will check the fuel pressure.
On Friday I have a Cardone rebuilt distributor coming thru Amazon. It comes with a new PIP sensor and TFI module.
What should the fuel pressure reading be?
Thank you.

[DerekTheGreat]

A distributer, so I presume this is a box with SEFI?

I had an '89 TC with a bad fuel pressure regulator- it just usually took a really long time to start, like double to three times what it should take. Never had any drivability problems with that car though. Matter of fact, I think it was smoother than my '88. Verify vacuum leaks and stuff too- make sure the line going to the MAP sensor is OK.

[jaywish]

IIRC 30lbs. An easy check if you have a gauge.

[sly]

Should be like 30-32psi running at idle (full vacuum) and around 40psi with the vacuum line removed.

[friskyfrankie]

Can't remember if you ever tried a new IAC? Personally, never had any luck just cleaning. My take is if I'm removing it anyway, might as well install a new one and clean the ports along with a new gasket.

[Tiggie]

I've only had one FPR fail and it was total failure. Pulled the vacuum hose off and fuel came out of the regulator. Barely ran from overloading with fuel, wouldn't idle and hard to start.

[gadget73]

I had an adjustable fail in a way that the pressure was all over the place. It ran lean, I'd bump it up to normal, then it would run fat. Lean pings badly and it makes poor power. Also get random hitching and bucking. Fat mostly just wastes a lot of fuel. It ran more or less normal.

Ignition is more cranky than fuel with most engines for regular driving unless its just way off the rails.

would be awful helpful to have exactly what you are working on in your sig. I have advanced CRS and just do not retain such details.

[stinkydogfilms]

It's a 1990 Colony Park with GT 40 heads, 65 MM throttle body, GT 40 intake and a Pro Flow 75 MM MAF.
The fuel pressure checked out good.
Starting fluid didn't help it either.
I'm going to try a new TFI module first. If that don't fix it, I have available, a new Cardone remanfactured distributor with a new cap, rotor, new PIP and new TFI module.
Can someone that's done it before, guide me thru swapping distributors?
I know it seems simple, but I tried doing one decade's ago and it turned into a pain in the ass.
BTW the spark test light last month and this time is an orange spark.
Thank you again.

[87gtVIC]

Swap distributor:

Turn car off.

Pop cap off of dizzy and take note where rotor is pointing.

Make note where TFI is pointing in relation to its surroundings.

remove dizzy bolt from lower intake.

wiggle dizzy and pull up...***rotor will spin some** make note where that is as well.

install rotor on new dizzy and place in engine. rotor should start where you last seen it positioned before dizzy popped off the engine.

rotor should end where you seen it before you started this process.

TFI should also be in same spot before you started this process.

place cap back on, or carefully swap wires one by one to new cap.

loosely secure dizzy hold down and set timing. tighten dizzy hold down bolt.

[gadget73]

I use sharpies to note where the rotor is before and after lifting, then just match the other one up. Fine-tune with the timing light.

also make sure cap tower 1 goes to cylinder 1. If someone hopped the wires around to fix an incorrectly dropped distributor it will do goofy things. Should be the only one marked.

[stinkydogfilms]

Thank you Vic and Gadget.
Has anyone had problems with the oil pump shaft coming out with the distributor?
Will the oil pump shaft slide back into the distributor easily?

[jaywish]

Never had that problem. Plus 1 on the sharpie. Also when you install the distributor make sure it is all the way down. If not remove and reinstall one tooth either way.

One thing that you might want to do before removal of distributor is make sure the rotor is pointing to #1. This will set the engine to approx TDC. Just in case you decide to have a few shots before doing the job and ... well you know.
Also clean and mark the balancer before you start the job so you can see it line up the 0 mark when matching the rotor to #1.

[gadget73]

The pump shaft is supposed to have a clip on it to prevent it from coming out with the distributor. Its not impossible that the clip is missing or not properly positioned and it jammed but I wouldn't worry too terribly much about it. If it falls, it can be fished out but you're jacking the motor up and dropping the oil pan to do it.

[stinkydogfilms]

Thank you all again.

[stinkydogfilms]

The new TFI module was not the answer. I checked the volts on the TPS. 1.47 Volts closed and 4.70 volts at WOT.
I went ahead and put the new distributor in. It had a new PIP sensor and a new TFI module. That fixed it. The idle is normal and the throttle pedal seems more responsive.
A bad PIP sensor I believe was the issue.