1991 Buick Regal hard shifts

[Merrillspontiac]

I just got my 91 back on the road after sitting all winter, and ive noticed a few issues, with it. after it sits overnight, it cranks for about 5 seconds before it starts. The transmission seems to shift hard from 1-2 then 2-3 under normal acceleration all the time, I also noticed that it stumbles if Im cruising anywhere from 50-60 MPH when I gently try to accelerate, but if I accelerate harder, it downshifts and accelerates just fine, trans fluid, filter plugs, wires and FPR are new as is the trans modulator I did do the seafoam treatment before changing the fluid and filter, there was no metal in the pan and the fluid looked good. could the TPS be faulty?

[myfirstbonnie]

How new is the transmission modulator? Check the vacuum line to it for cracks or leaks. Does it slam into reverse also? Is it an adjustable modulator.

Check all the vacuum lines by spraying them with carb cleaner. If the idle increases, then there is a leak where you sprayed it.

If you can, take a picture of the modulator.

[Merrillspontiac]

the modulator is brand new from advance, it is adjustable, it shifted hard before I changed the modulator as well, it shifts smoothly into reverse and drive, the vacuum lines were also replaced as well. it also seems like when im slowing down and it gets to 17mph, it downshifts a little hard too.

[myfirstbonnie]

You need to check the TPS and the adjustment on the TV cable. Have you checked the coils?

[Merrillspontiac]

I readjusted the TV cable and it shifts the same. so its most likely a bad coil or TPS?

[Merrillspontiac]

I readjusted the TV cable and it shifts the same. so its most likely a bad coil or TPS?

[myfirstbonnie]

If you have a meter, they can be checked easily. Do you have an SES light on?

[Merrillspontiac]

no SES lite, yes I do have a meter, what is the proper procedure?

[Merrillspontiac]

no SES lite, yes I do have a meter, what is the proper procedure?

[myfirstbonnie]

TPS:

http://www.pontiacbonnevilleclub.com/fo ... =48&t=9098

Coils:

http://www.pontiacbonnevilleclub.com/fo ... =48&t=1683

[Merrillspontiac]

I forgot to mention that when I slam the hood when the engine is running and its cold, it will stall out.

[myfirstbonnie]

Unplug the MAF while it is running and see if it idles different, dies, or no change.

[Merrillspontiac]

started up the car and unpluged the maf, the ses lite came on, plugged it back in the engine stumbled and died, disconnected it again, restarted it slammed the hood 3 times no stall, plugged it back in stumbled for a second than went back to normal idle abnd ses lite went out, slammed the hood and it stalled out.

[Merrillspontiac]

Im thinking that I have an issue with the MAF

[myfirstbonnie]

Check your TPS and coils first. The MAF is quite expensive. Have you taken the intake tube off and checked to make sure some critters haven't made a home in there? Get a can of MAF cleaner and remove it and spray it real good. Some people have even used a q-tip to clean the filaments, but I usually just spray them real good. Just don't use anything but MAF cleaner on it.

[Merrillspontiac]

can I use coils from a series II or series III?

[RJolly87]

Usually the official test for a MAF sensor, is to tap the black box of the sensor with the handle of a screwdriver, and if it is bad, the car will react to it.

[Merrillspontiac]

does it matter if it is warm or cold?

[94SilverSSEi]

Just a thought but couldnt u check the MAF by taking it out of the 92 and putting in in the 91 and see if there is any change that way you can rule out MAF

[Merrillspontiac]

swapped MAF and TPS with my 92, no change, tomorrow I will swap coils and see if anything changes.