Jump to content

97 f-250 4x4 460 extended cab long bed issues


Gump
 Share

Recommended Posts

It's EFI. Any old Ford nuts out there? Starts fine. Idles fine, shifts fine, just no power up hills. Almost as if it's not getting a timing advance or fuel. There's no pinging or backfiring, not running rich. Just sluggish.

I've checked the codes. Its clear and no dash light. It's obd 1.

Checked the plug wires, disconnected each injector and noticed a miss on each one so I assume those are good along with with spark.

Checked timing which is correct at 10BTDC with spout disconnected.

Checked TPS with a digital ohm meter and seems ok.

Butterflies are a little dirty but not sticking open and wouldn't cause the problem.

Checked all around for a vacuum leak

There is a MAP sensor and only has 1 02 sensor.

Catalytic converter has been removed so it not plugged.

Checked the air box it's clear.

Next I'll take a fuel rail reading and test fuel regulator I guess. Maybe check the EGR but I don't think the EGR would cause this amount of lack of power.

It recently had a new front tank and fuel pump installed. Rear tank is junk.

Not sure what else to look at besides compression check.

Read maybe it's the ICM (ignition control module) but I don't know how to test it and don't like just shotgunning parts into it.

Maybe O2 but I don't know. I had a Porsche once have an O2 go bad and resulted in a big power loss.

It's a beater truck and has been a pain in the $ss.

New rear hangers, shackles, lead springs, starter, right front wheel bearing, tires, radiator cap, battery cable ends, wiper blades, 7 pin trailer plug and some yahoo cut the factory tow package wire plug off at the back of the truck which included the reverse lights, constant power, and electric brake wire but I got it re-wired and was able to use the factory plug up front to tie the new brake controller into.

Edited by Gump
Link to comment
Share on other sites

So if I disconnect the idle air control it slows down the idle. I can't figure it's supposed to shut down the engine or just slow if down. If it's supposed to shut it down and my butterflies are closed at idle then I have vac leak somewhere.

Link to comment
Share on other sites

You could spray carb cleaner near all vacuum tubes etc and see if it changes the idle. If it does you can try to narrow it down from there.

I'll try it.

Link to comment
Share on other sites

It's EFI. Any old Ford nuts out there? Starts fine. Idles fine, shifts fine, just no power up hills. Almost as if it's not getting a timing advance or fuel. There's no pinging or backfiring, not running rich. Just sluggish.

I've checked the codes. Its clear and no dash light. It's obd 1.

Checked the plug wires, disconnected each injector and noticed a miss on each one so I assume those are good along with with spark.

Checked timing which is correct at 10BTDC with spout disconnected.

Checked TPS with a digital ohm meter and seems ok.

Butterflies are a little dirty but not sticking open and wouldn't cause the problem.

Checked all around for a vacuum leak

There is a MAP sensor and only has 1 02 sensor.

Catalytic converter has been removed so it not plugged.

Checked the air box it's clear.

Next I'll take a fuel rail reading and test fuel regulator I guess. Maybe check the EGR but I don't think the EGR would cause this amount of lack of power.

It recently had a new front tank and fuel pump installed. Rear tank is junk.

Not sure what else to look at besides compression check.

Read maybe it's the ICM (ignition control module) but I don't know how to test it and don't like just shotgunning parts into it.

Maybe O2 but I don't know. I had a Porsche once have an O2 go bad and resulted in a big power loss.

It's a beater truck and has been a pain in the $ss.

New rear hangers, shackles, lead springs, starter, right front wheel bearing, tires, radiator cap, battery cable ends, wiper blades, 7 pin trailer plug and some yahoo cut the factory tow package wire plug off at the back of the truck which included the reverse lights, constant power, and electric brake wire but I got it re-wired and was able to use the factory plug up front to tie the new brake controller into.

Link to comment
Share on other sites

I had a 93 with a 351 Windsor Tps went bad once it acted like that and I had 2fuel tanks and One had a bad fuel pump and inthe middle of a 2500 mile trip out west I had to useThe bad one for a hundredmiles with no balls

Link to comment
Share on other sites

The idle air control won't shut the motor down. It's an electric motor controller valve that adjusts airflow for the engine to idle at the correct speed. It opens and closes a small hole to allow air past the throttle blades. Same idea as opening the throttle just a crack but it's easier for the computer to control.

Did you ever get the fuel pressure checked?

Link to comment
Share on other sites

The idle air control won't shut the motor down. It's an electric motor controller valve that adjusts airflow for the engine to idle at the correct speed. It opens and closes a small hole to allow air past the throttle blades. Same idea as opening the throttle just a crack but it's easier for the computer to control.

Did you ever get the fuel pressure checked?

Yep. It's good. 40 key on. 33.5 running. No leak backs. I towed a 6000# camper with it tonight on state routes and it dropped to around 35 on the bigger hills. It's as if it has no torque after 2000rpm. The hose on the pvc valve sucks in on itself so I'll replace that because it's old. Re-checked TPS it's good. Timing good. Some Redneck put a plug wire on the ignition coil which has a smaller connector than your spark plugs so I crimped it till I get a new one. I'm out of ideas, there are no hose vac leaks. Guess I'll soak it in starter fluid.
Link to comment
Share on other sites

Not a Ford nut by any stretch, but I have quite a bit of experience with working on them!

 

What's the fuel pressure under load?  That is MUCH more important than the static pressure at key on, and idle.  Tape the gauge to the windshield, take it down the road and floor it.  The pressure should be pretty close to the key on engine off spec, since this would be a low manifold vacuum situation.  Fuel volume is important as well, but MOST of the time, if it's able to maintain pressure under a load, it has enough volume.

 

EGR should probably be commanded open pretty far at that point anyway, so that's not very likely the problem.

 

Is it misfiring when this happens?

 

Also, even though the catalytic converter is gone, the muffler can have stuff come loose and cause a restriction.

 

I'll keep this one in the back of my mind, and if I think of anything else, I'll post it.

Link to comment
Share on other sites

Not a Ford nut by any stretch, but I have quite a bit of experience with working on them!

What's the fuel pressure under load? That is MUCH more important than the static pressure at key on, and idle. Tape the gauge to the windshield, take it down the road and floor it. The pressure should be pretty close to the key on engine off spec, since this would be a low manifold vacuum situation. Fuel volume is important as well, but MOST of the time, if it's able to maintain pressure under a load, it has enough volume.

EGR should probably be commanded open pretty far at that point anyway, so that's not very likely the problem.

Is it misfiring when this happens?

Also, even though the catalytic converter is gone, the muffler can have stuff come loose and cause a restriction.

I'll keep this one in the back of my mind, and if I think of anything else, I'll post it.

Fuel pressure remained the same when given gas. I'll try brake torquing it.

Not missing that o can tell.

Wonder if the whole problem was week spark with the crappy plug wire for a cool wire. Didn't get a chance to drive it since.

I am intrigued that while checking for a vac leak with propane and then even purposely feeding the intake propane the idle didn't change.

Edited by Gump
Link to comment
Share on other sites

Fuel pressure remained the same when given gas. I'll try brake torquing it.

Not missing that o can tell.

Wonder if the whole problem was week spark with the crappy plug wire for a cool wire. Didn't get a chance to drive it since.

I am intrigued that while checking for a vac leak with propane and then even purposely feeding the intake propane the idle didn't change.

 

Propane?  I just use carb cleaner, or brake cleaner these days, as long as I know the plug wires are in good condition, and out of the way of where I'll be spraying.

 

I suppose a weak coil wire COULD cause it.

Link to comment
Share on other sites

Propane? I just use carb cleaner, or brake cleaner these days, as long as I know the plug wires are in good condition, and out of the way of where I'll be spraying.

I suppose a weak coil wire COULD cause it.

I used a vac pump on every single thing that could be tested. No leaks. Except for the one hose I broke of course. Then hosed it down with card cleaner with the IAC and distributor spout off. No change. Vac from intake is 19 and steady. Once you plug the IAC and spout back in then vac kinda bumps around slightly.

Link to comment
Share on other sites

I used a vac pump on every single thing that could be tested. No leaks. Except for the one hose I broke of course. Then hosed it down with card cleaner with the IAC and distributor spout off. No change. Vac from intake is 19 and steady. Once you plug the IAC and spout back in then vac kinda bumps around slightly.

 

Yeah, once you let the computer take back over, it will move around.  19 is pretty good, I wouldn't suspect anything mechanical, since you say that it doesn't seem to misfire.  I'll have to see if I can dig up some info on it, I'm limited in that area here at home.  It still sounds like fuel supply or air flow (in or out) to me.  If only you were closer!  

Link to comment
Share on other sites

Yeah, once you let the computer take back over, it will move around. 19 is pretty good, I wouldn't suspect anything mechanical, since you say that it doesn't seem to misfire. I'll have to see if I can dig up some info on it, I'm limited in that area here at home. It still sounds like fuel supply or air flow (in or out) to me. If only you were closer!

Any Info would be good, I'm running out of things to test/check/or replace. Lol The plug wire on the coil didn't change anything. Guess I could have the ICM tEsted.

Link to comment
Share on other sites

Any Info would be good, I'm running out of things to test/check/or replace. Lol The plug wire on the coil didn't change anything. Guess I could have the ICM tEsted.

 

ICM is unlikely.  It's ususlly good or bad, rarely in between.  It's pretty much just a dumb switch after the engine gets running, doing whatever the ECM tells it.  Typically, if it has problem, spark would be weak and causing a misfire.  I'm not ruling it out 100%, but I have serious doubts about it.

Link to comment
Share on other sites

ICM is unlikely. It's ususlly good or bad, rarely in between. It's pretty much just a dumb switch after the engine gets running, doing whatever the ECM tells it. Typically, if it has problem, spark would be weak and causing a misfire. I'm not ruling it out 100%, but I have serious doubts about it.

Ok. Even though it shifts fine and the converter locks up properly, have you ever heard of a converter robbing power at higher speeds? On another note, there are times it seems like hill power problem is gone. From a time perspective it seems to be on the same stretch of road.
Link to comment
Share on other sites

Ok. Even though it shifts fine and the converter locks up properly, have you ever heard of a converter robbing power at higher speeds? On another note, there are times it seems like hill power problem is gone. From a time perspective it seems to be on the same stretch of road.

 

Does it seem to get worse as the operating temperature increase?  

 

I believe it's a locked stator that will cause a similar condition.  There should be a plug, or plate that you can remove to look in at the torque converter.  Take a look, and if it looks like it's been HOT (usually blued) then you've found it.  If not, keep looking.

Link to comment
Share on other sites

Does it seem to get worse as the operating temperature increase?

I believe it's a locked stator that will cause a similar condition. There should be a plug, or plate that you can remove to look in at the torque converter. Take a look, and if it looks like it's been HOT (usually blued) then you've found it. If not, keep looking.

If It actually is better, it's about a half hour after its warm. I'd call it intermittent.
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...