Need serious help

rtgreen · May 28, 2009

If your running a K&N thats been over oiled it can cause hesitation because the oil is screwing with the MAF. You might want to clean the MAF...it's easy and cheap. Thats assuming that your running an oiled filter. Just my .02

AaRoN · May 28, 2009

Give it a full tune up. As you stated in the 1st post, the problem has transferred to the 03 engine. What common thing are you using from the 98 engine?

JDwhite98gt · May 28, 2009

I've cleaned the filter within the last month or so and didnt know i ran out of oil so never oiled it...the problem still persists. Aaron, I've done the full tuneup when I swapped the engine(fuel filter, plugs, wires, cleaned maf,TB, plenum, IAC) the only things that I re-used was the ecu, fuel tank, fuel pump, fuel lines, wiring harness things that you wouldnt usually take out when just doing the motor swap. My fuel rail is from my 96(just swapped this the other day, and still have the problem so regulator is good) so i could replace/upgrade the regulator when the time comes. I thought that maybe I had a blockage somewhere in the fuel rail, regualtor, etc. so I just swapped it over. Today, I had an extra maf laying around(actually I have two extras) so I cleaned it, swapped it and also threw on the extra coil packs I had laying around. I cleaned them with electrical cleaner and used contact grease, took it out and same damn problem. All I can think of is maybe the pump is going out or the previous owner who had the car pi headed, cammed, intaked somehow tuned the car wrong and I'm running this "tuned" 98 ecu thats not setup correctly. :BangHead:

95PGTTech · May 28, 2009

I got your PM.

To start with, that fuel pressure is pretty low. You should be seeing 40psi at idle and almost 60psi at WOT on Ford vehicles. Pull the plugs and take pictures, check the gaps. Do a quick compression test while you're at it.

But it really sounds like a tune issue. If it had mods on it already, there's a good chance it has a tune on it now. I hope you can contact the previous owner if this is the case, because if you can't get ahold of his handheld tuner, you're going to need to go to Ford and get the "as built" put back into the PCM, updated to the latest calibration. Not cheap. Then go out, get a tuner, and a tune.

JDwhite98gt · May 28, 2009

wow that would suck if it was a tuning issue. Yea i'm at only 28 psi at idle maybe 38-40 at wot. What would cause such a low fuel pressure?

95PGTTech · May 28, 2009

Pump, lines, filter or regulator on the feed side.

JDwhite98gt · May 29, 2009

ok maybe its the pump, I really hope its not a tunning issue...but i do have a copy of his registration in my glovebox but I know he's in the armed forces because his father sold it to me because he was in iraq. His dad seemed to know nothing...he told me it had header work lol it was pi heads and intake. But when you drove it, it was so sluggish you couldnt tell. Anyway I'll try to dig him up and find out today. thanks

JDwhite98gt · May 30, 2009

I was thinking about the tunning issue. Wouldnt a really good diagnostic tool let you see that parameters are changed? Like some of those like the snap-on MODIS look at timing, throttle position, maf readings all that. So wouldnt I be able to tell if it was tuned?

95PGTTech · May 30, 2009

You would be able to do it with the handheld tuner that loaded the tune or the Ford-provided dealership scan tool. I forget what the hell acronym they call it, I worked when the NGS+ was being phased out for the new product. Last I checked it was upwards of $25,000 and they replace it once a year. They add bullshit new features and touchscreen this and that to keep you buying new ones.

I am unaware of the capabilities of a MODIS.

JDwhite98gt · May 30, 2009

well the capabilities really arent that important. But if you can see timing, fuel pressure, a/f ratio on a scan tool wouldnt you be able to tell if its different than stock? I had my mechanic check all of those things and they were all stock..like timing and what not. Doesnt a handheld tuner usually change parameters like timing?

95PGTTech · May 31, 2009

No, the only way you can tell it's not stock with the Ford scan tool is to check for ECU updates and box code overrides. Seeing those parameters would possibly help identify a base issue, but it wouldn't tell you that anything has been tuned with a tuner - you'd be purely guessing what the factory A/F ranges should be, timing, etc. which can vary quite a bit.

JDwhite98gt · May 31, 2009

oh ok gotcha. thanks. But really hope it's just a fuel pump

98mstanggt · Jun 2, 2009

JDwhite98gt said:
oh ok gotcha. thanks. But really hope it's just a fuel pump

Did you find out anything yet?? My car did it again today

JDwhite98gt · Jun 3, 2009

well did my girlfriend's brakes the other day and took them to where I used to work to get them turned. Anyway talked to my ex boss and he says that it sounds like there is some kind of fuel cut off. If it was spark it would happen on throttle but since the problem only happens when I go: throttle, off-throttle(in gear), back on throttle and the car does not respond when I hit the gas, then I'm getting no fuel. So he said maybe cam sensor, crank sensor or worse case as already stated, a processing issue. But...wouldnt I get a check engine light if it was cam/crank sensor? I do have mil eliminators, and that shuts off the CEL for cats only right?

95PGTTech · Jun 3, 2009

you would get a code. processing issue...could easily be aftermarket tune or need for aftermarket tune adjustment. it's not a constant fuel issue, which is why I'm straying away from a hard part issue (fuel filter, pump, injector, etc.) it's only a specific situation issue. a lot of tuners struggle with the part throttle driveability stuff, car could be overfueled or underfueled on tip in.

JDwhite98gt · Jun 3, 2009

ok well if it needs a tune thats better than it already having a tune in it. I'm having a really hard time getting a hold of the guy I bought it from. I also took off the vaccum hose off of the fuel regulator and ran it for the day like that. Top end seems to pull a little harder or maybe I'm imagining things :dontknow: Anyway it keeps my fuel pressure gauge pegged at just a tick under 40 psi and it doesnt go any higher than that at any rpm or speed.

95PGTTech · Jun 3, 2009

You should be around 40psi at idle, but it should have jumped up quickly without the presence of vacuum there.

JDwhite98gt · Jun 4, 2009

oh it was instantanious after I removed the vacuum hose. Anyway, I've searched and searched for the previous owners phone number but its an unpublished number and I cant get it without paying some online company for it. I'm going off the his old registration that was in my inbox. Anyone know how I can get an unpublished number? only info i have is full name and address. Otherwise I dont know how to ell if this car has a tune.

95PGTTech · Jun 4, 2009

go and try and get the car tuned, try to upload another tune to it. it won't let you if it's currently tuned. if the tuner has any idea his ass from his elbow, he can get the as built put back in and then tune off of that. being in person, it'll also be a lot easier for him to tell you if your issue is a base engine issue or something he can help out with computer calibration.

joelbegt · Jun 7, 2009

Its probably a regulator prob, or a reg and fuel pump combo problem. go to a junkyard and pick up a cheap regulator for a couple bucks. Spark plug gap can close due to detination which would happen if its running lean. The other thing i would think it is would be the fuel pump due to the whining noise you hear when you turn your key to the on position. Id go see if you can find a reg for 10 bucks and see what happens. 28psi isnt enough pressure and the regulator controls that. unplug the fuse to your ecu for 5 min after all this. That will blank out the computer, because it has probably been trying to overcompinsate for low fuel pressure a long time.