91 Pontiac Grand Am Acceleration problem

I have a 1991 Pontiac Grand Am with a 2.5L TBI. I have noticed that, especially on hills, that the acceleration tends to warble (meaning it doesn't hold steady). I thought it was a clogging fuel filter, so I
replaced it. It still did it. Then, I changed the spark plugs. It still does it. I ended up changing the coil packs and ignition module because one of the packs failed and there was a crack in the module. I thought maybe that would have taken care of the problem, but it didn't.
Anything else I may have overlooked?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Joseph Emerson" wrote:
91 Pontiac Grand Am 2.5L TBI.
Acceleration tends to warble (doesn't hold steady), especially on hills.
Replaced fuel filter. Replaced spark plugs. Replaced cracked ignition module. Replaced coil packs (one was bad).
Problem still exists. Anything I may have overlooked? ____________________________________________
Please provide a little more info; you may be surprised to find someone has a clever fix to the problem.
POSSIBLE ADDITIONAL INFO: Actual throttle pressure (light,cruise, full), vehicle speed, period or frequency of warble, description of warble (sound and feeling), any action that makes warble better or worse, difference in warble on steep/mild hills, downhill, level pavement, etc.
Good Luck.
John & Wendy. ____________________________________________
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Well, during the last incident, I was going uphill steady on the gas pedal about 25-30 mph. It seems like it usually warbles going uphill in second gear before the automatic tranny shifts into 3rd. It sounds like a momentary dip in RPMs, as if I let up on the pedal. (But my foot is steady on the pedal.) (I disconnected the TCC since it sticks and causes my car to stall at a full stop.) It doesn't warble downhill or on level pavement.
Anything else you might need?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Joseph Emerson wrote: 91 Pontiac Grand Am 2.5L TBI.
Acceleration tends to warble (doesn't hold steady), especially on hills.
Replaced fuel filter. Replaced spark plugs. Replaced cracked ignition module. Replaced coil packs (one was bad).
Problem still exists. Anything I may have overlooked? __________________________________________________________
Please provide a little more info; POSSIBLE ADDITIONAL INFO: Actual throttle pressure (light,cruise, full), vehicle speed, period or frequency of warble, description of warble (sound and feeling), any action that makes warble better or worse, difference in warble on steep/mild hills, downhill, level pavement, etc.
Good Luck. Wendy & John. ___________________________________________________________
Last incident, going uphill steady on the gas pedal about 25-30 mph. Usually warbles going uphill in second gear before the AT shifts into 3rd. Sounds like a momentary dip in RPMs, as if I let up on the pedal. Disconnected the TCC (sticks and causes car to stall at a full stop.) Doesn't warble downhill or on level pavement.
Anything else you might need? Joseph Emerson ___________________________________________________________
No, thank you. I don't need anything else.
The symptoms described may simply indicate AT shift point hunting. A newsgroup reader with more experience than mine may recognize another problem and suggest a solution. Posters here gladly provide helpful suggestions for appreciative car owners.
Wendy & John. ___________________________________________________________
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.