Help.... Fuel pressure regulator ???'s

phat97yukon · December 21, 2005

Hey guys the last while crusing in town my 97 yukon it gets a weird feel, kinda like its miss fireing, at steady speeds, doesnt matter how fast tho... its kinda hard to explain, its like a pulsating feeling laging from the motor kinda like lack of fuel that you can feel in the whole truck, and even goin down the highway too, it feels like it looses power when your haulin ass and starts to sound odd like it wants to go but just lag's, before i could stomp it from a dead stop and hit the governer no problemo... the truck is tuned up good, new plugs, wires , cap rotor, O2's , fuel filter and so on, fuel pump was replaced less than a year ago also... Im just wondering if possibly it may be the fuel pressure regulator might be on its way out, and just isnt gettin enough at a steady speed.. My buddys dads 99 Hoe, his went they thought it was the pump its self, replaced it and ended up bein the regulator, the truck wouldnt run at all....

Also would a shot regulator cause bad gas milage ?

Any info on this would be great ! Im sick of pain in the arse problems..

phat97yukon · December 22, 2005

Help me pleeeeease...

02 Silverado Z71 · December 22, 2005

GUESSING is the absolute worst thing you can do. It already sounds like sombody threw a bunch of parts into your truck without fixing it.

Start with the basics!! Spark, fuel, compression.

Fuel pressure...what is it?? Should be around 60psi to 65psi.

You are saying constant misfire...get more information to us.

phat97yukon · December 23, 2005

GUESSING is the absolute worst thing you can do. It already sounds like sombody threw a bunch of parts into your truck without fixing it.

Start with the basics!! Spark, fuel, compression.

Fuel pressure...what is it?? Should be around 60psi to 65psi.

You are saying constant misfire...get more information to us.

<{POST_SNAPBACK}>

the pump was replaced cuz i had a screwed gauge, other than that it was all tune up stuff ive done, plugs wires rotor cap fuel filter.. The O2's were done cuz i was gettin a huge drop in fuel milage but now im back to 500+KM to a tank...

It has spark, checked its not missin threw there at all, Fuel it gets it, runs and everything, compression havnt tested it, but its still tight, doesnt use any oil between changes or anything, as for testin the fuel presure i got no clue how to check that crap, and i dont want to deal with takin it to a shop to get bent over for them to test it to find out that ive just given them enough cash to find out that it is the regulator, than have to buy one on top of that....

The problem feels like a sputter while your goin, like i said it kinda feels like a missfire thats the best way i can describe it... it happens while at a steady speed AT TIMES, not all the time... And even crusin at highway speeds, go and give it gas it just lags power, yet off the line right up to 130 KPH and up it wont have a problem if im hammer down, but at 110KPH and stomp it , it lags to get up and go hints why i think it could be a fuel problem IE starving its self......

Is there anyway i can test the PSI of the fuel ?

Ive had some other guys tell me that the regulator could be the problem, its been doin it for a while, before and after the tune up done, doesnt matter on grade of fuel i use either.. If there is anyother info you would like to know please let me know..

asilverblazer · December 23, 2005

Sounds like there aren't too many other things that it could be that haven't been replaced. Are there any codes? Or Lights coming on? If it was ME, I would replace the regulator... unless yours is the year under the manifold (I get confused). Definately sounds fuel related, and there just isn't to much in that system left...

phat97yukon · December 24, 2005

Sounds like there aren't too many other things that it could be that haven't been replaced. Are there any codes? Or Lights coming on? If it was ME, I would replace the regulator... unless yours is the year under the manifold (I get confused). Definately sounds fuel related, and there just isn't to much in that system left...

<{POST_SNAPBACK}>

Nope no codes, no lights nothin thats whats tickin me off, mine has the regualtor under the intake *blah* So looks like im goin to be doin some reserch on how this crap all goes together, anyone around replace one on a 97 vortec before that can give me some pointers that would be great...

rudder73 · December 26, 2005

This kinda sounds like you have some water or condensation inside your gas tank. Be careful where you buy fuel as some gas stations may have added water to their fuel tanks during the fuel crunch not long ago.

Look for an additive that removes the water in fuel tanks. MFI engines don't like moisture as water is extremely hard to compress.

dsheeler · December 28, 2005

i know exactly what you are talking about. My 96 Silverado has been doing that for a while now, cruising along at around 1800 RPM and every once in a while it feels like its misfiring-definitely weird. I am just learning about the Fuel Pressure Reg because last Monday the truck completely stopped running. It cranks and cranks with no issue, just won't fire up. Distributor was damaged so that was replaced but still nothing. Fuel pump turns on and actually sprays fuel, it's just not getting to the throttle body. My mechanic was at a loss so called a dealer who gave him 3 choices-Computer, Throttle body or Regulator. I told my guy to start with the cheapest first because I'm not one for just throwing in parts for the heck of it (and neither is my wallet for that matter ) I hope this will solve both my immediate problem and the ongoing problem of the "misfiring" but I'll keep you updated.

Mr. Smith · December 28, 2005

GUESSING is the absolute worst thing you can do. It already sounds like sombody threw a bunch of parts into your truck without fixing it.

Start with the basics!! Spark, fuel, compression.

Fuel pressure...what is it?? Should be around 60psi to 65psi.

You are saying constant misfire...get more information to us.

<{POST_SNAPBACK}>

the pump was replaced cuz i had a screwed gauge, other than that it was all tune up stuff ive done, plugs wires rotor cap fuel filter.. The O2's were done cuz i was gettin a huge drop in fuel milage but now im back to 500+KM to a tank...

It has spark, checked its not missin threw there at all, Fuel it gets it, runs and everything, compression havnt tested it, but its still tight, doesnt use any oil between changes or anything, as for testin the fuel presure i got no clue how to check that crap, and i dont want to deal with takin it to a shop to get bent over for them to test it to find out that ive just given them enough cash to find out that it is the regulator, than have to buy one on top of that....

The problem feels like a sputter while your goin, like i said it kinda feels like a missfire thats the best way i can describe it... it happens while at a steady speed AT TIMES, not all the time... And even crusin at highway speeds, go and give it gas it just lags power, yet off the line right up to 130 KPH and up it wont have a problem if im hammer down, but at 110KPH and stomp it , it lags to get up and go hints why i think it could be a fuel problem IE starving its self......

Is there anyway i can test the PSI of the fuel ?

Ive had some other guys tell me that the regulator could be the problem, its been doin it for a while, before and after the tune up done, doesnt matter on grade of fuel i use either.. If there is anyother info you would like to know please let me know..

<{POST_SNAPBACK}>

If you are feeling a misfire and all other things have been checked..ie vacunm leaks...I would lay odd you have an injector clogged as you say it is laying down on you. Getting the injectors cleaned is where I would look.

Shaners · December 29, 2005

The regulator could very well be the cause of your problem. Usually the first sign of a bad regulator is longer cranking times, or the motor not firing on the first crank.

Have you considered that the problem could also be something like the tranny torque converter? Or selenoid in the tranny?

phat97yukon · December 29, 2005

The regulator could very well be the cause of your problem. Usually the first sign of a bad regulator is longer cranking times, or the motor not firing on the first crank.

Have you considered that the problem could also be something like the tranny torque converter? Or selenoid in the tranny?

<{POST_SNAPBACK}>

Also i found it it seems not to do it with Cruise control on, i just did a 6 hour trip 3 hours each way 2 days ago with cruise and no probs flat ground or on hills doin 130KPH

kinda made me also thought maybe it could be the TPS...

I thought of the selenoid also the other day when it has problems on the highway, because when i was goin threw the mountins a couple months ago it was bein pretty stupid when you hit the gas it would do the same hesitation like when you step on it doin 110kph , makes intake noise but just lags.. is there anyway to test the tranny crap my self, also woulnt it send a code ?

Also i figured if it was somthing more tranny related , it would be a pain in the ass all the time even accelerating from lights and what not, but 3 weeks ago i towed a car back to town 3 hours, threw 2 major citys and no problemo gettin off the line of anything.

asilverblazer · December 29, 2005

When you used the cruise control without problems it was probably a combination of the cruise increasing the throttle in smaller increments than your foot, along with the ground being level meaning there was little load on the engine.

The 97 still has a throttle body right? With the injectors there, so if it was an injector I would think it would feel more like it was running out of gas because the injector would affect numerous cylinders, by the same token the FPR would do the same thing...

It seems like as long as you aren't having spikes in the amount of fuel being used (sudden wide open throttle) then the fuel pressure regulator can keep up,but when there is a sudden increased need for more fuel it gets lazy and starves the engine. Since it doesn't do it from a standing start wide open throttle it can keep up easier because the flow and engine load is increasing at a more steady rate. If it were an injector I would expect to see the engine missing or starving under any circumstance, not just sudden wide open throttle.