New to me truck issue

shoprat

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I bought a 97 F-250 Heavy Duty with the 351 Windsor/5.8l, and I think the E40d trans from some friends. It only has 103,598 miles on it as of this morning. It sat for almost 6 years with very little driving, the owner I got it from said less than 1,000 miles in 6 years. I have done the usual tune up stuff to it, new fuel filter, fresh gas, changed engine oil/filter, new plugs, distributor cap and rotor button with new wires. Here is the problem: when taking off in drive the motor will pull for a bit then cut out like it is starving for fuel, let off the gas for a second and then give it more it will take off again. It will do this up too about 37 mph then it will go like a champ. If I put it in second gear and go it will not cut out, when I get it to 40 mph I just upshift to drive manually. When I come up to a hill and try to kick it down for more power it will not kick down until I lift off the throttle. Then it will only stay kicked down for a split second and it upshifts again. What is going on with this truck???????? I only paid $800.00 for it, it has some rust in the normal places cab corners, floor pans, rockers, and drivers side bed corner. I am just now at $1000.00 with all of the tune up stuff, taxes, and registration. With this low of miles I am wanting to get the rust taken care of and drive it till it dies, then swap in a 7.3 IDI and a 5 speed manual trans. Thanks for an and all assistance with this issue.
 

LCAM-01XA

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I bought a 97 F-250 Heavy Duty with the 351 Windsor/5.8l, and I think the E40d trans from some friends. It only has 103,598 miles on it as of this morning. It sat for almost 6 years with very little driving, the owner I got it from said less than 1,000 miles in 6 years. I have done the usual tune up stuff to it, new fuel filter, fresh gas, changed engine oil/filter, new plugs, distributor cap and rotor button with new wires. Here is the problem: when taking off in drive the motor will pull for a bit then cut out like it is starving for fuel, let off the gas for a second and then give it more it will take off again. It will do this up too about 37 mph then it will go like a champ. If I put it in second gear and go it will not cut out, when I get it to 40 mph I just upshift to drive manually. When I come up to a hill and try to kick it down for more power it will not kick down until I lift off the throttle. Then it will only stay kicked down for a split second and it upshifts again. What is going on with this truck???????? I only paid $800.00 for it, it has some rust in the normal places cab corners, floor pans, rockers, and drivers side bed corner. I am just now at $1000.00 with all of the tune up stuff, taxes, and registration. With this low of miles I am wanting to get the rust taken care of and drive it till it dies, then swap in a 7.3 IDI and a 5 speed manual trans. Thanks for an and all assistance with this issue.

Scan the PCM for codes. You may find one for the TPS or the MAP sensor. Possibly the VSS as well, have you noticed the OD light on the shifter blinking at you? KEep in mind the truck uses Ford's EEC-IV engine & transmission management system, not OBD2, so a bit of guess work and chasing things on the mechanical side (like rotted vacuum lines and frayed harnesses) is involved. Should be a good truck once everything is fixed up. Also I wouldn't bother with an IDI swap, hop the 5.8 up a bit (heads from a 5.0 Exploder would be a good start) and drop a ZF behind it and it will scoot along quite good.
 

shoprat

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Thanks for the response. I should have mentioned that the overdrive button is missing. I have a new gear selector in route right now from rock auto. I am hoping that will help it. I am gonna pull the throttle body off hopefully today and clean it up and see.
 

LCAM-01XA

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I'm not sure if the PCM will look for the shifter button or not, pretty sure it only needs it for cancelling the overdrive gear, but don't quite me on that. Do you have the light on the shifter at least, and does it blink at you?

Yes the TPS on these being on the bottom of the TB makes it a pain to adjust, but you don't have to pull the TB just to check the TPS, you can probe the wires at the connector between the TPS and the engine harness - one will read 5V, another will be ground, and the third one should be around 1V while throttle is closed. You check for that with the ignition on but engine NOT running. When you find the 1V at idle wire, keep the meter on it and start manually opening the throttle, watch how the readings change - you want smooth increase, any sudden jumps or drops indicate worn TPS that warrants replacement. But like I said, you'll probably have code for that in the PCM, so scan it too.

VSS, that's a tricky one, usually when the VSS itself fails you get jumpy speedometer to tell you something is wrong. However if the VSS itself is good, and the PSOM instead is fixing to give up the ghost, you may see good speed readings on the gauge while the PCM still doesn't get the proper speed signal it needs. Again, scan the PCM, if you get a VSS code while the speedometer reads fine you're likely in need of a new PSOM. Well, naturally you can use one off a donor truck, just need to check on your conversion constant first and then reprogram the new unit as needed - this is done without any tools, just pushing the PSOM buttons in a certain sequence.
 

shoprat

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OK so I didn't get the Throttle body cleaned as I had hoped, had to help a bud get wood split for the winter. I did test the MAP sensor, it checked out. Hoping tonight after a wood splitting marathon to get the TPS checked and see if that is the issue. If the TPS is out of adjustment would that cause the problems that I am having? As far as start and idle it does great. It only takes it maybe 2 or 3 revolutions to fire up and it idles right along never has stalled or died on me. I'm gonna test it tonight and see if the TPS is shot or what. Thanks again for the reply and assistance.
 

LCAM-01XA

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I'm thinking you may have a semi-worn TPS with a dead spot in it halfway up its range, when you're in 2nd gear all the way you're giving the truck more throttle and the TPS is past its dead spot so it reads right and the truck runs good. The E4OD transmission is a fickle beast, the PCM needs to have all the appropriate inputs for it to run right. Is the TPS the cause for your trobles, maybe or maybe not, but it is a good place to start investigating as it is one of the most important sensors the PCM looks at.
 

shoprat

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OK so it is not the TPS, I replaced it. Replaced the shifter. The map sensor checked out when I tested it. Does anybody have anymore suggestions for it?
 

LCAM-01XA

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Scan the damn thing! You can throw parts at it all day long and still not get it right. You have EFI and electronic transmission, use them to your advantage to hopefully reduce the guesswork...
 

79jasper

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Can't you get a specific scanner for the trans codes on those things for like $40? Lol

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LCAM-01XA

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Don't need a transmission-specific scan tool - the transmission brain you're thinking of is still EEC-IV, just lacks the engine controls. But that's would be what you'd find in an IDI truck, his gasser has one PCM for both the engine and the transmission. Still EEC-IV, still produces the same codes. An EEC-IV scan tool from Rock Auto was indeed under $40 shipped last time I checked (few months ago), and this is the one that shows real numbers for the codes - I can't put up with any of that count the blinks of the light nonsense, I wanna look at an actual number on the screen.
 
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