Dajain
Newbie
Hey guys and gals!
OK, I have done so much to this truck and she still has a miss, problem shifting and really lacking power.
1991 454 TBI meshed with 4L80e transmission
The motor:
I'll start at the top.
New AC Delco injectors
New IAC
TBI rebuild kit
New vacuum hoses for the entire TBI set up
New MAP sensor
New cap, rotor, spark plugs, and wires
Eliminated the dreaded antifreeze coupler in the intake. Yes, it broke off. lol
Timing while operating temp is 4° BTDC
Cold, dry, WOT compression test showed 112 - 130 PSI on all the cylinders. I'm sure the numbers would be better warmed and a wet compression.
New O2 sensor
New starter
New 2.5" exhaust
Transmission:
New shift solenoids and manifold
New fluid
New wiring harness
still has the old speed sensors on it.
The problems....
The miss.
It really seems to have a hard miss under acceleration. Idle does have a slight miss
With the new injectors and ignition system, I would think the power would be greater than what it is. It is really doggish.
But, I wonder if my shift issue is connected.
The shifting:
Goes thru all the gears but takes forever to get up to 60 mph.
Starting out from a stop, it wants to stay in 1st gear. Let off the throttle and it shifts to second, but apply just a little throttle and she kicks back down into 1st gear.
Once in 3rd, don't even feel it shift from 2nd or into 4th. Shifts are very smooth.
I didn't replace the TPS. That could be the issue.
Maybe the speed sensors in the transmission are not reading properly?
I would really like to get this running the best she can. Does anyone have any new ideas what the problem could be.
Thanks in advance!
OK, I have done so much to this truck and she still has a miss, problem shifting and really lacking power.
1991 454 TBI meshed with 4L80e transmission
The motor:
I'll start at the top.
New AC Delco injectors
New IAC
TBI rebuild kit
New vacuum hoses for the entire TBI set up
New MAP sensor
New cap, rotor, spark plugs, and wires
Eliminated the dreaded antifreeze coupler in the intake. Yes, it broke off. lol
Timing while operating temp is 4° BTDC
Cold, dry, WOT compression test showed 112 - 130 PSI on all the cylinders. I'm sure the numbers would be better warmed and a wet compression.
New O2 sensor
New starter
New 2.5" exhaust
Transmission:
New shift solenoids and manifold
New fluid
New wiring harness
still has the old speed sensors on it.
The problems....
The miss.
It really seems to have a hard miss under acceleration. Idle does have a slight miss
With the new injectors and ignition system, I would think the power would be greater than what it is. It is really doggish.
But, I wonder if my shift issue is connected.
The shifting:
Goes thru all the gears but takes forever to get up to 60 mph.
Starting out from a stop, it wants to stay in 1st gear. Let off the throttle and it shifts to second, but apply just a little throttle and she kicks back down into 1st gear.
Once in 3rd, don't even feel it shift from 2nd or into 4th. Shifts are very smooth.
I didn't replace the TPS. That could be the issue.
Maybe the speed sensors in the transmission are not reading properly?
I would really like to get this running the best she can. Does anyone have any new ideas what the problem could be.
Thanks in advance!
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