Just to update everyopne on the results of my TPS replacement.

At 80 MPH it now goes into overdrive... also it had a rough idle problem before the swap that is now resolved. It is now getting 20 MPG at 65 mph but it drops to 18 at 80... much better than before it was averaging 15 at 80 before because it wouldn't go into OD..... I noticed an overall improvement in shifting, and engine performance... it even climbs hills better on cruise now!!!!

I still have a slip when downshifitng to merge..... and sometimes it slips a little from 2-3... This is to be expected for an automatic with 220,786 miles on it and hasn't been rebuilt...

I am thinking about changing the fluid and filter again... anybody care to reccomend a good synthetic tranny fluid??? I've got to keep this thing on the road until the first of next year at least... then it's going to a friend to get the tranny rebuilt...


-Mike-

 

Mine shifts into OD at about 45mph. I just put in Mobil 1 synthetic in my tranny and it seems to get better mileage 24 mpg at 70mph.
That is with an AWD with 3.73 gear ratio. The mileage is using Canadian gallons.

 

What I meant by it now goes into OD at 80 was not that it actually always shifts at 80, but when under hard acceleration onto the interstate and once I was out on the interstate it would 'hang' in third gear and would not go into OD.... I never had a problem with OD at lower speeds..... As you can imagine staying in third gear going 80 or better will eat up a lot of gas, as well as alternators... LOL

I killed an aged alternator... long story...

anyway, thanks for the fluid reccomendation...


-Mike-

 

I was just about to post another Q on the TPS.

I have had a mild-moderately rough idle and replaced the TPS - with no effect.

However, a few Q's:

as I have a '91 Aerostar, do you guys know there was a emissions recall for the TPS?

and Chiltons says the TPS must be calibrated and not for the home mechanic to touch it.

Opinions please?

 

When I decided to do mine I was told that there was nothing that could be calibrated or adjusted. You take the old one out and put the new one in.

I am not aware of any recalls pertaining to emissions. Maybe just on the '91's...

The only thing that may be necessary after doing the TPS replacement is disconnecting the battery to clear out any codes that are in the computer, however I did not disconnect the battery and mine is running fine. I bought the replacement from NAPA for $28.00...

Don't try to do it while the engine is hot because that upper radiator hose will make it very difficult while hot.....

A rough idle could be many things... the easiest to fix are: replace air filter, clean the MAF sensor, clean the IAC valve, clean the throttle body. after that is done disconnect the battery for 30min to clear the codes, hook everything back up and test it. If there is still a rough idle you may need to consider plugs/wires and or distributer cap & rotor if they have not been changed... most of my rough idle was resolved after a tune-up.. they found that my ignition coil was cracked and was causing it to surge and stall, if let idle too long... it was also causing a 'mis' during road operation as well.


-Mike-

 

Thanks Aerostarman2002.

Apparently the recall was for 1990-91 years. About 500,000 affected. I just aclled the stealership and they said it should be calibrated to 1 volt....whatever.

I had a tuneup about 20k miles ago. The rough idle has been progressive. I will clean the IAC valve and check for vac leaks first.

 

aerostarman. i must know, when you say a miss during road operation, do you mean a high rev miss, like it misses during higher rpms. cuase i think thats whats trubling my van. mines a 94 aerostar 3.0 and its kinda low on power. going to get it tuned up soon though. it might just be a bad plug but if thats what you mean then my van might suffer from the same ailments, so that information may be vital to the proper running of my van.