Miss at startup
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Joined: Jan 2004
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From: SW Va
Fastow, have you had the computer scanned for trouble codes????
If not, why not run this puppy by your favorite autoparts store for a scan, most will do it at no charge, then post ALL the codes found. Maybe it'll sniff out a good clue to follow up on!!!!
If not, why not run this puppy by your favorite autoparts store for a scan, most will do it at no charge, then post ALL the codes found. Maybe it'll sniff out a good clue to follow up on!!!!
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Joined: May 2002
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Yes pawpaw i did have a friend run it on his snap on scanner and it past every test and it did no trouble codes. We sprayed carb cleaner through the air intake as while it was running and unhooked the battery to try and reset the computer. thought maybe at first we had something but after driving it, it still is rough when started cold and it sometimes will stumble when running down the highway it s like someone shut the switch off and on .
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Joined: Jan 2004
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From: SW Va
Well if the fuel pressure reading you posted is accurate, it's more than double what it's supposed to be, according to my Haynes manual, which lists the pressure range as... KOEO (Key On Engine Off) 35 - 45 psi.
At idle with the fuel pressure regulator vaccum hose CONNECTED, pressure should be 25 - 35 psi. Or about 10 lbs lower than the KOEO reading, but between the 25-35 lb reading.
At idle, with the fuel pressure regulator's vacuum hose DISCONNECTED, pressure should be 35 - 45 psi. Or it should RISE to about the KOEO number with no regulation.
If you don't get the psi RISE by disconnecting the fuel pressure regulators vacuum line, replace the regulator.
Needless to say, if the fuel pressure is really as high as the numbers you've posted, you have a fuel pressure regulator problem IMHO!!!
I'm surprised your friends SnapOn scan tool didn't spot the excessive fuel pressre, it should have, if your readngs are real.
Recheck your pressue readings, as I've listed above & confirm they are high & if so, double check your vacuum lines to the regulator for leaks, if they are ok, then replace the regulator & be shure to test the new one & let us know how things go.
At idle with the fuel pressure regulator vaccum hose CONNECTED, pressure should be 25 - 35 psi. Or about 10 lbs lower than the KOEO reading, but between the 25-35 lb reading.
At idle, with the fuel pressure regulator's vacuum hose DISCONNECTED, pressure should be 35 - 45 psi. Or it should RISE to about the KOEO number with no regulation.
If you don't get the psi RISE by disconnecting the fuel pressure regulators vacuum line, replace the regulator.
Needless to say, if the fuel pressure is really as high as the numbers you've posted, you have a fuel pressure regulator problem IMHO!!!
I'm surprised your friends SnapOn scan tool didn't spot the excessive fuel pressre, it should have, if your readngs are real.
Recheck your pressue readings, as I've listed above & confirm they are high & if so, double check your vacuum lines to the regulator for leaks, if they are ok, then replace the regulator & be shure to test the new one & let us know how things go.
Post Fiend
Joined: Jan 2003
Posts: 9,748
Likes: 16
From: Connecticut
Originally Posted by pawpaw
Well if the fuel pressure reading you posted is accurate, it's more than double what it's supposed to be, according to my Haynes manual, which lists the pressure range as... KOEO (Key On Engine Off) 35 - 45 psi.
At idle with the fuel pressure regulator vaccum hose CONNECTED, pressure should be 25 - 35 psi. Or about 10 lbs lower than the KOEO reading, but between the 25-35 lb reading.
At idle, with the fuel pressure regulator's vacuum hose DISCONNECTED, pressure should be 35 - 45 psi. Or it should RISE to about the KOEO number with no regulation.
If you don't get the psi RISE by disconnecting the fuel pressure regulators vacuum line, replace the regulator.
Needless to say, if the fuel pressure is really as high as the numbers you've posted, you have a fuel pressure regulator problem IMHO!!!
I'm surprised your friends SnapOn scan tool didn't spot the excessive fuel pressre, it should have, if your readngs are real.
Recheck your pressue readings, as I've listed above & confirm they are high & if so, double check your vacuum lines to the regulator for leaks, if they are ok, then replace the regulator & be shure to test the new one & let us know how things go.
At idle with the fuel pressure regulator vaccum hose CONNECTED, pressure should be 25 - 35 psi. Or about 10 lbs lower than the KOEO reading, but between the 25-35 lb reading.
At idle, with the fuel pressure regulator's vacuum hose DISCONNECTED, pressure should be 35 - 45 psi. Or it should RISE to about the KOEO number with no regulation.
If you don't get the psi RISE by disconnecting the fuel pressure regulators vacuum line, replace the regulator.
Needless to say, if the fuel pressure is really as high as the numbers you've posted, you have a fuel pressure regulator problem IMHO!!!
I'm surprised your friends SnapOn scan tool didn't spot the excessive fuel pressre, it should have, if your readngs are real.
Recheck your pressue readings, as I've listed above & confirm they are high & if so, double check your vacuum lines to the regulator for leaks, if they are ok, then replace the regulator & be shure to test the new one & let us know how things go.
However, keep in mind that the '98 Ranger is equipped with a "returnless" fuel system which is a little bit different than the standard Ford fuel system used up thru '97 (on Ranger's anyway). In the "returnless" system, there is no return fuel line from the fuel rail back to the tank, and the fuel pressure regulator is actually inside the tank along with the pump assembly. The fuel pressure specs are also different, since the system operates under a higher pressure. Take a look:
1998 Ranger
- All gasoline engines (except 3.0L FFV): KOEO/KOER = 64±8 psi
- 3.0L FFV: KOEO/KOER =55±8 psi
In any event, it's still evident from the above that the numbers fastow posted aren't even in the ballpark.
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From: SW Va
Good point Rockledge, thanks for straightening me out on that, somehow my foggy mind thought we were talkig about a 94, 4cyl, doublechecking it, I see it's a 98, 4cyl!!!! Dang pitiful when my mind can't remeber something long enough to turn a page!!!! LOL
You know, the build sheet on my 99 4.0L says it has a feedback fuel system!!!! Was something different on 98's?????
You know, the build sheet on my 99 4.0L says it has a feedback fuel system!!!! Was something different on 98's?????
Elder User
Joined: Jul 2005
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If it is the OVERHEAD CAM engine (It will say SOHC on the cover) then it's likely to be the intake gaskets. Fairly easy to replace.. no coolant travels through the plastic intake... just don't tighten the bolts too much your you'll crack it. You might even have a "extended warranty" on it, (a "recall" campaign extends it to i believe 10 years/150k miles). If yours isn't covered I would purchase the recall kit from ford.. comes with all the gaskets and a new chain tensioner (easy to replace once intake is off), as it's cheaper than just getting the gaskets. The gaskets (look like rubber bands) get brittle and leak when cold... and the mildest increase in temperature allows them to seal up again, hence the rough cold starting.
If you have the non overhead cam engine, then this does not apply.
Another possibility is coolant leaking into the combustion chamber due to a leaking head or intake gasket. Have you had to add any antifreeze? Sometimes they leak so little it doesn't show any symptoms, but while sitting a couple droplets make their way into the cylinders, causing it to run rough until it burns out.. (a couple seconds or so)...
Just a couple ideas to consider...
If you have the non overhead cam engine, then this does not apply.
Another possibility is coolant leaking into the combustion chamber due to a leaking head or intake gasket. Have you had to add any antifreeze? Sometimes they leak so little it doesn't show any symptoms, but while sitting a couple droplets make their way into the cylinders, causing it to run rough until it burns out.. (a couple seconds or so)...
Just a couple ideas to consider...
New User
Joined: May 2002
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Sorry its been awhile gettin back on here. This truck of mine is still being a problem after installing the fuel pump , disconnecting the battery to reset the computer and running carb cleaner through the ait intake while it was running it seems maybe a little better but still there is times when it still idles rough and will fall on its face out on the highway. Something I thought about is on the fuel rail where the fuel line connects looks to be some type of regulator with a vacuum hose hooked to it I havn't checked it out but just wondered if it could be bad or the vacuum line somewhat plugged. Some other food for thought is when i had the fuel pump out there was some type of valve in the line between the pump and where the line hooks to come out of the tank It had a return line on it while I had the pump out I took this out A mechanic at the parts store said that it was not used with a after market fuel pump. In the directions for the new pump there was no mention of this piece and nothing even pictured in the instructions. I'll keep everyone posted and thanks for the reply's and info.
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Senior User
Joined: Mar 2005
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From: South Texas
That thing on the fuel rail with the vacuum hose on it is your fuel pressure regulator. I had one go bad a few years ago and my truck did exactly what you are describing, so check it. Someone posted a way to check it above using a fuel pressure gauge on the system. Another low tech way to test it is to pull the vacuum line off it just after running it. If there is any fuel in that vacuum tube then the regulator is bad. Good luck.
Post Fiend
Joined: Jan 2003
Posts: 9,748
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From: Connecticut
Originally Posted by irishguyincc
That thing on the fuel rail with the vacuum hose on it is your fuel pressure regulator. I had one go bad a few years ago and my truck did exactly what you are describing, so check it. Someone posted a way to check it above using a fuel pressure gauge on the system. Another low tech way to test it is to pull the vacuum line off it just after running it. If there is any fuel in that vacuum tube then the regulator is bad. Good luck.
In a returnless fuel system, the pressure regulator is in the tank. The little thingy on the fuel supply manifold with a hose coming off of it looks very much like a FPR, but it's not. It's actually a fuel pulse damper which purportedly reduces fuel injection "noise". The vacuum port coming off the damper is connected to manifold vacuum so as to avoid fuel spillage in the event the damper’s diaphragm were to rupture.
fastow, I can't help but think back to what you said about the fuel pump replacement repair job you did. It sounds to me that you might have changed some things around (you said you removed a fuel line with a valve that was in the tank) that probably shouldn't have been.
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Joined: Aug 2005
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My 98 explorer 4.0 sohc idles rough when I start it up and hesitates getting on the freeway in the morning. I've replaced the #4 spark plug 3 times in the last year. the wires, coil, fuel filter, and vacuum leaks have all been eliminated as possible causes. my mechanic thinks it's a blown head gasket, but there is no coolant in the oil and it doesn't overheat. If it is a blown head gasket, what are the cons of just replacing the spark plug instead of repairing the blown head gasket?
Post Fiend
Joined: Jan 2003
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From: Connecticut
Originally Posted by irishguyincc
That's good to know, thanks for the correction and info Rockledge.
FYI, the reason Ford (and others) are going with the Returnless Fuel Systems has to do mostly with emissions. Getting rid of the return line is one more tweak in the never-ending quest toward lower evaporative hydrocarbons. The less fuel lines and fuel travel distance, the less chance for hydrocarbons to get into the atmosphere.
Another benefit is that, only the fuel that actually gets used makes its way up through the fuel supply line(s) to the injectors; the excess (or bypass) flow doesn't have nearly as far to go and average fuel flow rate is thereby reduced, saving wear and tear on the pump. This is so even though most returnless systems operate at a higher pressure (as is the case with my '98, for example). The higher pressure helps with vaporization issues, especially during warm starts.
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HUM Rockledge sounds like your up on this stuff. So what your saying is the thingy I removed in the fuel tank I sould not have done I thought when doin it maybe it could have been the fpr but like i said a mechanic said and in the instructions to the fuel pump there wa no mention of it. I think the mechanic and parts place thought the thing in the tank was the fuel pulse damper your theory seems more right. That said tonite when I was at the parts store I ask if they listed a fuel pressure regulator they did for like 40 bucks and the pic looked just like the one on my fuel rail. Some one also mentioned maybe the feul pressure was regulated with voltage supplied to the pump via the computer.I just hate keep throwing parts at this thing but i guess if i was paying a garage to do it they might be following the same path and costing me even more.
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went to the parts store tonite was going to get the fpr that they had listed for the 1998 after a closer look it was not the same deal had him look up fpr for a 99 they don't list one. they just list a complete pump assembly with the float and in the pic the regulator thingy on it for like $269.00 I think i am off to the savage yard.