Just finished giving $2500 to tranny shop for an overhaul and transfer case reseal/checkout The shop says I have an early computer that has some less-than-optimal shift programming. It locks up after shifting into 2nd, and is still locked when shifting into 3rd, causing a bit of a hard shift. They said that a new computer would have better programming. My question is, would one of the aftermarket chips fix this? I have a Hypertech now and didn't really see any change. Truck is a '91 F-150 4x4 5.8L, I have a TransGo shift kit installed and new exhaust including a high-flow cat.

 

First thing to do is visit your nearest Ford dealer. Ask them if they have any updates for your ECU code (Ford is CONSTANTLY updating codes and has hundreds of them).

Also, shift kits don't always work well with performance chips (including the Hypertech) unless you can dial the shift down or get the chip with a soft shift.

Question..... what transmission do you have? If its not electronic, there isn't anything a chip can do for the shift pattern...

 

It's a '91 E40D. From the descriptions I have seen, I can't tell if the chips alter transmission function. If I go to the dealer, do they just change some programming or replace the ECU? Is this expensive?



:-X12

 

The chip will alter the transmission shifting sinces its an electronic controlled transmission.

Getting your current computer upgraded by Ford shouldn't be expensive. They aren't changing anything out, merely "reflashing" with updated code. Only takes them a couple of minutes to do this...

 

I was told the EEC-IV (OBD-I) used in the 1991 F150 had a ROM not an EEPROM and was not flashable. They told me the newer EEC-V (OBD-II) computers used after about 1995 were the flashable variety.

If there is a way to flash EEC-IV ECMs I would be *extremely* interested. There is a small eec tuner industry building electronic plugin PCM cards to reprogram these computers. See:
www.eec-tuner.com

Just my two cents.

John

 

Let me rephrase that :-) .... as them to replace the PROM with an update, if available. PROM chips themselves are cheap (a couple of bucks). How much Ford charges for the code in the PROM, however, isn't something I know but it must be significantly less than a whole new computer.

Another route would be to see if you can obtain a new or used computer from another source, that tuner you mentioned is a way to experiment if you're comfortable changing settings yourself. Just be careful, you CAN damage your engine if you lean it out too much, among other things.

wookie1, what is your current code? Let me know and I'll see about digging up a list of alternative EEC codes and/or computers so at least you'll know what to ask for if you want to check with Ford or another source for updates...