Power Drops out at 3k

[urdrvideo]

Hey folks,
I have a 5-speed disco on 245's with a OME lift...
I have noticed for quite some time that my truck does not like to make any power above 3k.
All my maintinence is up to date, the motor has 105k on it It make no noises, and is so smooth you barley hear it running.
But when I hit 3200 RPM it is like I am bouncing off of a soft rev- limiter. I do not hear any funny noises but the power just goes away...

Any body have any ideas?

Thanks

Dennis

 

[nosivad_bor]

check your fuel pressure and filter.

 

[deiaggie]

Vacuum advance?

 

[FIVESPDDISCO]

i have the same flat spot. then at 3700 it pics up again

 

[urdrvideo]

Well this morning the drop out was more pronounced, and it came on at 2200RPM went away, and then again at 3200. I really cant rev too much past 3200 because the lack of power does not allow the truck to pull out of it...

 

[andrewv]

Vss?

 

[p m]

it was vacuum advance + plugged catalytic converters on [formerly] my 89 RRC.

 

[urdrvideo]

Interestingly enough the dropout at 200RPM did not start occuring until I fixed my Cruise Control (had a few split vac lines...)
I would assume there is a connection between the two, but I could be wrong.
Any thoughts?

Dennis

 

[p m]

tee off the vacuum line going to your distributor (I am assuming your D1 is a 94 or 95), and see what the reading is. It should increase with increasing of the engine RPM and the load (throttle open wider), from a few inHg at idle to ~15-20 at high engine speeds.

 

[urdrvideo]

Guys,
thanks for all the feedback on this problem, It is not solved yet, but I do not think I am far away.
For the record my truck is a 96, so I will not be able to put a tee in line off the distributor.

Dennis

 

[warner0188]

Sorry for the hijack. I'll be watching this post closely since my '96 Disco has been doing something very similar for a very long time. The difference with my truck is that it only does it after it warms up; usually about 15-20 minutes. I have replaced the following within the last year and a half since it first started:
Fuel tank recall with new overflow hose
Fuel Pump - pressure is b/n 35-38 psi
Fuel Filter
Plugs
Wires
Throttle Position Sensor
Stepper Motor
Cam Position Sensor
MAF - replaced w/ used
Engine ECU - replaced w/ used
Ignition Coil Pack
Fuel Injectors - cleaned fuel rail & resealed intake at the same time
new hoses from valve covers to the plenum
oxygen sensors -4
cats - both
resonator (muffler)
Optima Yellow Top
Thermostat
viscous fan clutch
I also found the wires going to the crank sensor had melted and were touching metal to metal. This was causing the engine to cut out at about 2k rpm randomly. It especially liked to do this when I would go through a large puddle. I taped the wires and it seems fine if I can just get this other problem fixed.

 

[warner0188]

bump

 

[urdrvideo]

Well...
I am beginning to believe that the problem I am having is Ethanol related, We have 10% here, and since my truck sat for a few months (6) with half a tank of gas I may have some water in the tank.
I really do need to go ahead and have the recall on tha tank done so maybe it will go away then.