need some help with a 97 ford 4.6 romeo engine.

[Swims350]

so my borther in law bought this piece a crap 97 f150 with a 4.6 romeo in it, had a bad miss, turned out to be a burnt valve on the DS. got it fixed, still runs horrible.

checked the FPR and it holds vac. makes no difference vac. or not applied while running, egr holds vac, new plugs, new wires, changed every fuel injector with known good ones, still nothing, changed the egr solenoid and a couple of other sensors with good known working ones.

No codes, only an evap one, runs terrible, bad miss at idle, smooths out over 2k rpms, trys to die once you let off, unhooking several injectors while running does no change, a few do drop it down further. coil packs have nice blue spark.

fuel pressure is good and in spec.

we're lost on this thing, was told it's not even run if it was out of time, it's a single over head cam motor one over each head so 2 cams total, and has 2 coil packs, four cylinders on each pack.

any ideas? computer? oxygen sensors? timing?

 

[davbell22602]

so my borther in law bought this piece a crap 97 f150 with a 4.6 romeo in it, had a bad miss, turned out to be a burnt valve on the DS. got it fixed, still runs horrible.

checked the FPR and it holds vac. makes no difference vac. or not applied while running, egr holds vac, new plugs, new wires, changed every fuel injector with known good ones, still nothing, changed the egr solenoid and a couple of other sensors with good known working ones.

No codes, only an evap one, runs terrible, bad miss at idle, smooths out over 2k rpms, trys to die once you let off, unhooking several injectors while running does no change, a few do drop it down further. coil packs have nice blue spark.

fuel pressure is good and in spec.

we're lost on this thing, was told it's not even run if it was out of time, it's a single over head cam motor one over each head so 2 cams total, and has 2 coil packs, four cylinders on each pack.

any ideas? computer? oxygen sensors? timing?

Have you it on a scantool? If so what is live data showing? What do the spark plugs look like? Have you checked the map sensor?

 

[crazy4offroad]

I would say IAC but ford doesn't have an IAC, it should be drive-by-wire which means there's a fuel feed motor or something like that, which has the TPS and IAC built into it. It is expensive, sorry about his luck. Hopefully that aint it but that's what it sounds like to me. If it turns out to not be drive-by-wire look for an IAC and clean it.

 

[oneluckypops]

I would say IAC but ford doesn't have an IAC, it should be drive-by-wire which means there's a fuel feed motor or something like that, which has the TPS and IAC built into it. It is expensive, sorry about his luck. Hopefully that aint it but that's what it sounds like to me. If it turns out to not be drive-by-wire look for an IAC and clean it.

Actually 97's do have IAC motors. So yes the IAC is a possability.

The most overlooked causes for these symptoms are. DPFE valve and or plugged EGR tube, they also have a tendency to clog in the intake manifolds.

I have also seen the 2 vacuume hoses that go to the DPFE valve be crossed up and cause all kinds of problems.

A little tip for ya, when replacing ANY of the emmisions parts, make sure you replace them ALL, DPFE, EGR, Purge, and quite possably the tube.

 

[Swims350]

no it has an IAC and it has a tps as well. But no scan tool only an actron code reader, I think it's a scan tool but I've seen no data from it at all.

the plugs last time were gas soaked, changed them, no difference, changed a few the other day, no difference

I call it an IAC, silver can, about 3 inches long, has 2 holes and a plugner in it, mounts on the side of the TB, has tube coming off it to let air in I guess since it's in the air intake.

alright I'm new to fords what's dpfe?

I already changed canister things with vacuum lines going to them, the egr tube is new, and the egr valve itself was not changed but it can be easily.

 

[crazy4offroad]

IAC is idle air control valve, I know my taco ran like **** once mine got sooted up, still ran great when you gave it gas though but just wouldnt idle. I dont think it ever threw a code either when that happened. Cleaned it with carb & choke cleaner and worked the valve till I was sure it was moving freely, reassembled and it ran great after that!

 

[oneluckypops]

no it has an IAC and it has a tps as well. But no scan tool only an actron code reader, I think it's a scan tool but I've seen no data from it at all.

the plugs last time were gas soaked, changed them, no difference, changed a few the other day, no difference

I call it an IAC, silver can, about 3 inches long, has 2 holes and a plugner in it, mounts on the side of the TB, has tube coming off it to let air in I guess since it's in the air intake.

alright I'm new to fords what's dpfe?

I already changed canister things with vacuum lines going to them, the egr tube is new, and the egr valve itself was not changed but it can be easily.

Sorry should have clearified that.
DPFE is a Delta Pressure Feedback EGR Valve. In my experience with ford EGR related problems you almost always have to replace the entire system to fix them. There are ways to "test" each part but honestly it is reallt finicky and does not always show bad. Not say NOT to test it as everyone on this forum is aware I am a FIRM beleiver in diagnostics and NOT just throwing parts at it.

I have actually considered renting my scanner out for the people on the forums that dont have one, But kind of scared to for the price of it.

 

[oneluckypops]

Heres a link for some decent reading on the valves http://www.focushacks.com/?modid=80&ht=DPFE Sensor and EGR Information Its for a focus but never the less its a ford. Your DPFE will look a little different but still opereates the same.

 

[HotRodPC]

For a 97 model, I'd prefer the 4.6 over a 5.4 any day of the week. And it doesn't matter if its a Romeo or Windsor block in the truck motors like it does in the Mustangs and Crown Vics.
I had a 97 Ford Lariet 4x4 X cab with a 4.6 and 98 Eddie Baur Expedition 4x4 with the 5.4. I could tow the same weight with both uphill and both kept the same speed. Only difference was, the 4.6 stayed in 2nd gear a hair longer and built the rpms up a little higher. The 4.6 was fairly good on gas, the 5.4 drank it like water, and I had more problems with the 5.4 than I care to talk about, and the 4.6 was flawless and I never put a wrench on it other than to change oil.

 

[Swims350]

ok I changed that yesterday with a known good working one, as well as the egr canister thing it shows too, the solenoid I think they call it, onl thing not changed was the egr itself. I can change it though to see if it helps. I tested it before and it holds vac. fine. It stays completely shut off as well.

 

[oneluckypops]

ok I changed that yesterday with a known good working one, as well as the egr canister thing it shows too, the solenoid I think they call it, onl thing not changed was the egr itself. I can change it though to see if it helps. I tested it before and it holds vac. fine. It stays completely shut off as well.

You need to have it running to properly test an EGR valve. Just cause it holds vacuume doesnt mean it is doing its job. Quite possably there is carbon built up behind it

 

[Swims350]

I had it off nothing behind it, and I even tried the egr with it running and such. it runs just doesn't idle smooth, and misses.

 

[Swims350]

digging up this old thread, we finally got this truck half running decent. Now, over a year later just about.

Not sure if I had mentioned it but they paid a guy to take off the head and change a valve because the second cylinder on the DS was dead, zero compression.

He put it in time wrong, fired it up and bent new valves.

The one valve that was burnt causing zero compression had a hole burnt in it as big as your pinky finger.

So my wife's uncle tore into it, they replaced every valve on that side, spent a few hundred on parts, got it running nice, then BAM!!!!!!! locked the thing up, timing chain(which was new) flew off and dropped every valve, well at least it broke or bent every rocker, and most likely every valve.

So they finally took my advice and put the motor they bought for $300 from a 98 crown vic in it. They paid a guy to do it too, since I didn't have time, so now it runs and drives.

Runs rough, gonna have to tune it up and it smokes for some reason.

We've been working on it the last few weeks, them guys got the motor in and going, brake pedals tuck down when you hit it, bought a new MC and booster cuz guys on the net had the same problems and fixed it doing that, well no luck, ended up just needing the thru bolt backed off. Saw another guy had that happen to his and it was fine afterwards, sure enough unhooked the booster rod and the pedal stayed down, so I backed the nut off(lock nut) about 1/4 turn and she was freed up.

Then we ran it some and it wasn't charging, they bought a brand new battery and alternator before and a new starter, had the new alt. checked and was fine, then after reinstalling and checking wires it started charging fine.

Then we had to bleed the brakes and boy aint Ford stupid, couldn't get a wrench on the bleeders good due to the wheel cylinder design, and the bleeders that were in it, so we had to use a socket and that wouldn't fit too good either, bleeder was already rounded off. Twisted the line in 2 trying to remove it from the wheel cylinder, so a new line, new wheel cylinder and some bleeders we got it done. The stupid bleeders we bought in an assortment none fit the rear either, so we had to clean and reuse the PS one, then used new bleeders on the front calipers. Ford put the front hoses right over the bleeders up front which was dumb, and then in back used 2 different sized ends on the brake lines, big size at the flex line and smaller on the wheel cylinder, how stupid IMO.

So now we are down to just changing the plugs, wires (which are new) and maybe coil packs. You can hear and see the spark jump ar the PS coil pack.

runs nice when it's cold, but after about 5 minutes or so run time or a short 1 mile trip or so it starts missing pretty bad, around 1500 rpms or so, but once you get it moving it does ok, trying to fix the bad miss so he can drive this thing.

Also the tailpipes both fell off due to rust, noticed the frame had been double plated with 1/4 plate due to rust I guess, I would have sold the heap seeing that crap. They already overpayed for this piece a turd to begin with, $3,750 I think it was, and he said it had bad gas is why it missed LOL.

 

[foamypirate]

Wow. Remind me to never buy a Ford. Not that I needed reminding, really.

 

[Swims350]

LOl no doubt, it reminded me why i don't own one.