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E4OD downshift points?

Hello all; I have a '90 Econoline with a 5.8 and E4OD electronic transmission. I've owned this truck since new (best and most trouble free vehicle I ever owned, I might add) and it still runs that way. One little thing that has always irritated me is the programmed transmission downshift points. In normal driving as I increase throttle it won't downshift until the manifold vacuum is so low the engine sometimes pings. Of course by mashing the gas past the "ping" it shifts fine but then I'm accelerating a little too fast. An aftermarket MAP sensor helped the problem slightly (put it in not long after I bought the van). I don't really want to spend the money (I think they were around $400) on those aftermarket "transmission computers". Anyone know of another "electronic" way of tricking the computer into thinking that possibly the manifold vacuum is slightly lower or some other way to get downshifts with slightly less throttle?

Jim

Reply to
JFLEISC
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adjust the throttle position sensor

you should see about 0.65 to 0.90 volts at closed throttle

Reply to
Gary Glaenzer

Yup, done that some time back, adjusted it to both extreams, and even replaced several of them. No difference.

Jim

Reply to
JFLEISC

call Ford and get a replacement ECM for it

the early ones had some screwy quirks in the programming

Reply to
Gary Glaenzer

How early? Are you talking about only their control of the trans or the engine also?

Jim

Reply to
JFLEISC

mainly transmission, especially pressure rise vs throttle position, shift speeds, and lock-up strategy

the parts guy may say 'it's the same as you have now', because the part number is the same, but the programming is updated

Reply to
Gary Glaenzer

get the ecm "flashed" by the dealer. (Reprogramed)

It will install any updates in the ecm that were developed after the truck was manufactured.

may not help the shift points if you have a worn tranny....but if it's in the programming it will.

runs about $75.

scrib abell

Reply to
Scrib Abell

Jim, There are devices made by Baumann Bros., Banks Engineering and others to alter the shift points of this trans. One that I have heard good things about is called The Interceptor which works with your ECM. Baumann Bros and others make a unit that controlls the trans independently of the ECM for performance apps. I would not recommend changing the ECM. Also, You may have a problem with your TPS which does not change voltage signals properly. Since you mention ping before downshift, I also suspect you have a problem in your EGR ssytem. I have seen the EVP sensor cause this problem. The TPS or the EVP sensor can be out of specs without setting a fault code because of the adaptive capabilities of the ECM. Again, I would not condemn the ECM until there is no other possibility. Id did do the job properly at one time with it's current prgram. The idea is to find out what changed to cause your current problem - it was not the program strategy of the ECM.

Reply to
lugnut

Over the years I have checked into or changed the listed parts you mentioned. I think there is one misunderstanding; Nothing "changed" to cause this problem. It's always been like that since the day I bought it new. In fact it was a tiny bit worse with the factory MAP sensors. Installing an aftermarket MAP sensor seemed to make the situation more tolerable. Since I plan to be buryed in this van 20 or 30 years from now I would like it to run a little better. Thanks for the leads though.

Jim

Jim

Reply to
JFLEISC

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