Jerk and Buck-Fuel.Pump.or.FPR-Update

Bluntz

Registered User
So in my excitement of getting my SC started today i promply took it for a drive, theres a few periodic jerk and bucks, like it was missing or somethign but i know it isnt(new plugs coil dis). After 20 miles i go to car wash and then home. I then decided to go for a longer drive on some errands i had to run, approx 70 mile trip. Well 10 miles in shes a buckin hard, something dont feel right but i pressed on. Im on my way back home and about 10 miles from my house she bucked one last time and left me on the side of the ~~~~in road. The car felt like fuel came to a trickle. with hazard lights on i limp the car to my friends house 2 miles away. if i give it gas it stalls if i let it idle it drives me about 15 mph and i feather the gas slightly. I made it to my buddies house and now my beautifull SC sits in another mans garage.

Question, to me it is obvoiously the fuel pump, could i be wrong and it be the fuel pressure regulater? What do i wanna get for a fuel pump? Quick napa search shows one for my car priced at $112.00 FPR is only about $30.
Any advice?
 
Last edited:
Were you able to check the fuel pressure at the rail.....:confused:

From what you are describing, I think you have a blown intake gasket or some kind of vacuum leak......:mad:

While the engine is at idle, take a 3 foot piece of vacuum hose and gently put on end into your ear.....

The the other end and probe around the intake and head junctions and around the IC tube junctions.....

If there is a leak, you will hear it....:cool:

A cracked spark plug or bad plug wire can cause the same symptoms that you are having....
 
Last edited:
If you changed the plugs and didn't change the wires, they may be the culprit but from the symptoms you describe, my first guess would be fuel pressure regulator followed by the fuel pump and then the wires, after all they are just a piece of string soaked in carbon and covered with rubber---if you pulled on them to get them off the old plugs, more than likely you broke the carbon"wire" inside and if so they will burn and go bad unless you have some aftermarket plug wires that actually have wire in them---pretty rare these days..............Dan
 
I am heading out to go get my car now, where exactly is the fuel pressure regulator located, and am i able to change it as people wait or is it a longer job? What tools do i bring?
 
FPR is ~~~~ to replace.....:mad:

It is located on the fuel rail at the rear of the engine near the firewall next to the drivers side valve cover.....:rolleyes:

There is a bolt in the back of the drivers side head that holds the fuel rail to the engine (you can only feel for it).....:mad::mad::rolleyes::mad:

I would check for correct fuel pressure (there is a place right on top of the fuel rail) before I would attempt to take the fuel rail off....
 
Sounds more like an ignition problem than a fuel delivery problem. Check balancer, check crank sensor harness for contact with supercharger belt, check dis module connections.

You mentioned the DIS module was new...is this a Ford replacement and did you put the heat sink grease under the module ?

David

PS: Please tell me it's not a Screamin Demon coil pack.
 
FPR is on the fuel rail under the lower SC tube back by the plenum bolted to the intake manifold.

bucking is often an ignition problem, not fuel. My 90 would do that when the cam sensor was flaking out. No check engine light, but would store a code about missing CID signal. Disconnecting the cam sensor and driving it around would verify.
 
We bought a car with those symptoms and it turned out to be a hole rusted into the fuel pressure regulator????? it would idle fine but stumbled like a big dog if you gave it gas....Like everyone said, put a fuel pressure gauge on the fuel rail and see what it is instead of guessing............Dan.
 
AGREED PUT A FUEL PRESSURE GUAGE (THEY ARE 20 BUCKS AT SEARS) AND SEE WHAT THAT SAYS. YOU SHOULD HAVE 30-35 PSI AT IDLE WITH FUNCTIONING REGULATOR. i THINK IT GOES TO 40 OR SO WITH REGULATOR UNHOOKED.

DID YOU PULL THE VACUUM LINE OFF THE BACK OF REAR MOST INTAKE THAT GOES TO THE REGULATOR? SOUNDS LIKE A VACUUM LEAK TO ME ALSO.

BUT YOU WILL NEED A FUEL PRESSURE GUAGE FIRST!!!!!!!!!!!!
 
I'm thinking a vacuum leak would make it idle crappy and run somewhat decent as rpm's climb---this one seems to be the other way around so I'm thinking more ignition or fuel....just my $.02..Watch it turn out to be the IRCM?????..........Dan
 
Last edited:
I searched autozone for IRCM and didnt find anything, where is this piece located and what is the part name? What does ircm do?
 
The IRCM is located in front of the air cleaner and behind the headlight on the passengers side of the car and they are year and model sensative so you have to have the right one....in addition to the relays that are on the module (I believe but may be mistaken, fuel pump, ac clutch, and high and low speed fan relays) there is also a little regulator transistor that regulates the 12volt battery voltage down to 5 volts for many of the sensors and if it gets flaky or the connections get flaky your car can and will do some flaky things (ask me how I know).................Dan
 
Last edited:
Now listen, you guys are awesome and so far this experience has been a adventure not all bad. HOWEVER....... Holy mutha #$#$%^^!!! I have never had such a hard time on a part, this fpr is the biggest pain in butt i have had displeasure to work on. Understand this is my first time doing it, but man, intercooler pipes have to come off, and the worst part of it is the bolts are allen wrench and to make things worse they are under the part not above. Sorry to sound so whiney but i am just stunned at how difficult this part removal is. why couldnt they have the bolts on top? i got 1 of the 3 off, the easiest one, i have no clue how i am gonna get the other 2 off, right now i am exploring trying to get my hand behind the motor to get to this bolt that i believe holds the whole fuel rail. I hope i didnt do this for nothing but if i did at least it is done.

By chance is this job easier done under the car?
 
Now listen, you guys are awesome and so far this experience has been a adventure not all bad. HOWEVER....... Holy mutha #$#$%^^!!! I have never had such a hard time on a part, this fpr is the biggest pain in butt i have had displeasure to work on. Understand this is my first time doing it, but man, intercooler pipes have to come off, and the worst part of it is the bolts are allen wrench and to make things worse they are under the part not above. Sorry to sound so whiney but i am just stunned at how difficult this part removal is. why couldnt they have the bolts on top? i got 1 of the 3 off, the easiest one, i have no clue how i am gonna get the other 2 off, right now i am exploring trying to get my hand behind the motor to get to this bolt that i believe holds the whole fuel rail. I hope i didnt do this for nothing but if i did at least it is done.

By chance is this job easier done under the car?

You should use a test gauge to confirm you really have a pressure problem before changing the regulator. Yes the early model regulators are a real pain to change. It a lot easier if you remove the supercharger.

David
 
Dont worry, after the 13th time taking the top end off you will be a pro at it. Everything becomes easy after a bit......

Justin
 
you should use a test gauge to confirm you really have a pressure problem before changing the regulator. Yes the early model regulators are a real pain to change. It a lot easier if you remove the supercharger.

David

he just doesnt listen!!!!!

Checke the fuel pressure there are simple checks to determine if the regulator is bad. But he doesnt listen and never checks it.

Take it to a dealer!!!!!! By now you have thrown enough parts at it that you could have had it worked on and be driving it now i bet.
 
just wanted to apologise for the rant earlier.....

but seriously. several of us has recommended that you check fuel pressure and how to check the regulator on other posts that you have made. and it just seems to me and i am sure some others here that you just wana throw parts at it. then post threads on how to remove or do something because of it.

i really hope you get this car running but just rember to follow the advise everyone gives you here or they will stop giving it out.
 
Back
Top