88 7.4L TBI loss of power issue

[sboaterdude]

I have a 1988 chevy 1 ton dually crew cab with dual tanks with just shy of 200K miles. I have started to have a driveability issue which is mainly loss of power. The truck will start and idle fine, but as rpms come up, power goes bye bye.

I have replaced plugs, wires, cap and rotor. I have replaced ignition module and coil. I don't think it is fuel pump as the truck has dual tanks and each tank has its own pump and I doubt both would go bad at the same time. I have tried new ECM.

I do have a scan tool and the truck is not showing any codes.

Any suggestions are appreciated.

[maxwedge]

Try disconnecting the cat see what happens, also new fuel filters? This is not a misfire but it just lacks power? Make sure both TB injectors are working, also.

[sboaterdude]

I also did a new fuel filter. There is only one which is after the swith over valve.

It doesn't seem to be a miss as it idles very smooth. It moves and will accelerate if you take it easy, but when you get deeper in the throttle, it stops accelerating and bogs down.

[maxwedge]

Pull the exhuast down from the manifold if you can.

[777stickman]

Another indication of a plugged CAT, or a resticted exhaust sytem, is an increase in engine coolant temp when it's bogging down trying to accelerate.