P38 idle

Right did cam covers and refitted plenum runs at 2krevs and don' rev so we stripped off plenum and refitted it to try again and still runs at 2k revs but getting no response off the throttle at all it' got lpg fitted it' a 4.6 v8 p reg p38 .....just wandering what to treat or see if any one has had same problem

You can't beat a bit of bully (English)

I realise I am pointing out the obvious here but the throttle cable is connected?

Yh is connected

Sounds to me like the throttle pot is either not working or not connected correctly/properly.

What' the throttle pot ....right I ge5ting 2000 revs I'm getting no acceleration if u blip it but if u slowly depress it it will rev ...ive tried looking for leaks with soapy water and can' see no leaks

Davidosik said:

What' the throttle pot ....right I ge5ting 2000 revs I'm getting no acceleration if u blip it but if u slowly depress it it will rev ...ive tried looking for leaks with soapy water and can' see no leaks

Click to expand...

OK, sounds even more like throttle pot now. It's a small black box on the side of the throttle body which measures the position of the throttle butterfly. (do a search on Google for p38 throttle potentiometer to see what it looks like)
It sounds like it's either using a default value because the reading is wrong or it's giving something like 50% all the time. The reason it will rev a bit if you do it slowly is because you are opening the butterfly to let more air in so the ecu will add more fuel to get the mixture correct.
I can't guarantee its the throttle pot but given the same symptoms, it's the first place I would look.

It should look something like this.
https://rimmerbros.com/Item--i-ERR7...asV0DCfeOWOb_6AGzrBZQGswgT1XOxyBoCfs0QAvD_BwE

It could also be the MAF sensor but I doubt that would give your symptoms

Ive unplugged the maf and the revs drop and pick back up ....ive got an obd2 code reader and I have no codes showing on it but it's only a cheap one ... I just can' understand it was ok before I changed rocker gaskets and now I have this
Issue

Your cheap obd2 won't work. You need nonocom. I'd bet a reasonable amount of readies that it's the throttle pot.