Power loss till about 3,000rpm

[logicgear]

i am having the a problem with my 90'. We did a motor refresh (all new gaskets, distributor, TFI Module, Cap, Rotor, Plugs, wires, & Fuel Pressure Reg) about a week ago. the cats are only a year old. got new magnaflow ones. and ran F'in Fabolus for like three days then one day it just feel on its face. it studders between idle/2k - 3k rpm then at three takes off. when crusing down the highway if it gets above 2,200 ish it feels like it wants to shift and it studders till 3k or untill i force it to down shift and get above 3k and it takes off. you can acully feel the the power change.

 

[WIDTIO]

How old or how many miles are on the fuel filter?

 

[loneranger48]

maybe a clogged fuel line.the same thing happened on one of my other toyotas i had.

 

[triumphrider-1]

I blame the A4LD.

 

[logicgear]

i'm gonna change the fuel filter today cause it is kinda old. the reason i'm starting to think it isn't a fuel system problem because the rpm doesn't change when it stutters. it almost feels like its in the tranny.

 

[IMenriched]

i'm gonna change the fuel filter today cause it is kinda old. the reason i'm starting to think it isn't a fuel system problem because the rpm doesn't change when it stutters. it almost feels like its in the tranny.

good idea

if that don't help it's down to getting codes &see what is tripped

during the "tune up"...did that include a 02 sensor?

 

[logicgear]

fuel filter didn't fix it. 02 sensor is only a year old it has maybe 18,000 miles on it. i'm thinking either the transmission module or the fuel pump.

 

[IMenriched]

fuel filter didn't fix it. 02 sensor is only a year old it has maybe 18,000 miles on it. i'm thinking either the transmission module or the fuel pump.

getting codes would point you in the direction of the culprit....

for example; you could have a faulty sensor that is causing over fueling or under fueling issue giving the symptom that you described. that in turn saves you funds that would go towards something else, just trying to help.

you can by all means just start replacing parts in hopes to eventually replace the problem....unless your going for a eventual restoration and things are going to get done anyway.

 

[logicgear]

ok all here is the latest.

Checked Codes - DTC 11 - System Passed No Codes

Fuel Filter - New

Throttle Position Sensor - New
Idle Air Control Valve - NEW
Manafold Absolute Pressure Sensor - NEW
Coolant Temp Sensor - New
Vehicle Speed Sensor - New

Distributor - New
Ignition Control Module - New
MSD Coil - A year old - Tested (Ristance Better Then New Stock Coil)

Tune Up - All New

O2 Sensor - 18,000 / 10 months old
Intake Air Temp Sensor - Old (about 5 years)
Fuel Pressure Regulator - Orignal (tested and just as good as the new one)

Fuel Pressure:

Keyed Ignition on and off 5-7 times to build pressure to 40psi
Once truck was started the psi droped to 30-32psi
When I stabed the throttle it droped down to 26psi then jumped back up to 40psi


The truck still studders and serges from idle to 3k rpm

 

[IMenriched]

ok all here is the latest.

Checked Codes - DTC 11 - System Passed No Codes

Fuel Filter - New

Throttle Position Sensor - New
Idle Air Control Valve - NEW
Manafold Absolute Pressure Sensor - NEW
Coolant Temp Sensor - New
Vehicle Speed Sensor - New

Distributor - New
Ignition Control Module - New
MSD Coil - A year old - Tested (Ristance Better Then New Stock Coil)

Tune Up - All New

O2 Sensor - 18,000 / 10 months old
Intake Air Temp Sensor - Old (about 5 years)
Fuel Pressure Regulator - Orignal (tested and just as good as the new one)

Fuel Pressure:

Keyed Ignition on and off 5-7 times to build pressure to 40psi
Once truck was started the psi droped to 30-32psi
When I stabed the throttle it droped down to 26psi then jumped back up to 40psi


The truck still studders and serges from idle to 3k rpm

the getting codes ...is that with KOEO and KOER?? aka..was that with engine off or running?

1st thought was it might have a bad spot on the TPS (throttle position sensor), although unlikely considering that it has been replaced.

trust that all the ground wires and vacuum lines have been scrutinized & determined to be good??

have you had it running (idling)...and sprayed sprayed it along the vacuum lines and intake mating surfaces...see if it picks up rpm /smoothes out. try to stay away from the exhaust manifold.

other suspects

sticky/dirty injector??

how is the compression?

was it previously ,or still is, running rich??? or lean?
others report that if it had a bad case of running rich....even thought your O2 sensor is relatively new it can take it out....

 

[351rangerxxx]

are you sure the hold down on the dist hasnt been lose and timing has shifted?

 

[logicgear]

the getting codes ...is that with KOEO and KOER?? aka..was that with engine off or running?

1st thought was it might have a bad spot on the TPS (throttle position sensor), although unlikely considering that it has been replaced.

trust that all the ground wires and vacuum lines have been scrutinized & determined to be good??

have you had it running (idling)...and sprayed sprayed it along the vacuum lines and intake mating surfaces...see if it picks up rpm /smoothes out. try to stay away from the exhaust manifold.

other suspects

sticky/dirty injector??

how is the compression?

was it previously ,or still is, running rich??? or lean?
others report that if it had a bad case of running rich....even thought your O2 sensor is relatively new it can take it out....

KOEO was the DTC 11

KOER : all that cames up said ( but i am going to run it agian)

CYL: 6
Cylinder number


Vacuum lines are good and there are no vacuum leaks. did the spray check.

haven't checked injectors. they are a few years old. they have about 110,000 miles on them. they are the second set that has been in the motor.

haven't checked the compression after the refresh (not sure if brother did it before giving me the truck back)

are you sure the hold down on the dist hasnt been lose and timing has shifted?

havent dubble check it but i guess i can check it agian.

 

[Ranger44]

At first I thought maybe you had a 3.0 in there.

All humor aside. The fuel pressure seems a little screwy. It should increase, don't decrease. You fuel pump, or is it fuel pumps? may not be providing sufficient fuel volume.

Other than that i blame the A4LD......

 

[logicgear]

well the fuel pressure is alowed to drop from no lower then 30 when you stab the throttle then the pump catches up within a second or two witch from what i understand is normal. i am making an appotment with my tranny guy to look at it in a few weeks. other then that i'm at a loss and don't know what to do other then take it to the local ford shop and have them look at it.

 

[logicgear]

ok everyone IT'S FIXED. thank you to 351rangerxxx just dubbled checked the timing and it was 20 degrees BTDC and it should be 10 degrees BTDC. The Screw Twaz Lose.