1996 D1 backfiring and wont rev

[cdansan]

Driving home from the trail my disco wont Rev and is very slow.
Backfiring under the hood when under load, easing out of the throttle seems to make it better.
I will check fuel pressure tomorrow.
I am thinking either VSS or CPKS, am I on the right track?
thanks, Dan

 

[Vic00Dis]

Thinking jumped timing Chain check that ! easy to do.

 

[Buddy]

I had similar issues when my CKPS went bad. It would idle OK but lost all power under throttle. if I really babied it I could get it up to speed but very slowly.

 

[cdansan]

I have a spare CKPS, I will put it in just to see what happens.
It is intermittant I drove it today with no issues.
Fuel pressure is 35 psi engine off key on, 27 psi idling and at constant throttle position.
Fluctuates up and down from 20 to 35 psi revving the engine up and down.

 

[D Chapman]

Fuel pump probably.

If the VSS is bad the speedo will be all fucked up.

If something was wet all bets are off.

 

[Mongo]

Also check and make sure your cats aren't shot...

 

[cdansan]

I think my problem is fuel related now.
At startup there is 35 psi fuel pressure, with about 10 psi drop when free revving the engine.
Drive 18 miles to work there is 20 psi of pressure that falls to near zero when free revved.
System does not hold pressure over night, no starting issues yet. Cycle the key and 35psi everytime.
Pull the vacuum line from the regulator - no change, I have 17hg of vacuum at that hose location.
I am going to change the fuel filter first, as it has not been changed since I have owned it. 4 years 30k miles.
I have a spare fuel pump relay to try as well.
If no change from there I will change the pump.