Crewmen

[crewmen86]

I have a vy 5.7 ls1 crosstrac crewmen it was on gas but I have removed the gas and now running on 98 octane, it was running rough on the gas but once it come off it come abit better then started to run rough then replaced the fuel pump it went real good for a day then went back to running rough again now won't start also replaced air flow sensor,plugs,leads,idle air control valve

 

[Fu Manchu]

Look at vacuum leaks first. Super common and super easy to fix. Make sure all your hoses are soft, not hard.

You’ve done the other things, plan to get the intake off. Give it a good clean. New gaskets/seals. Torque down to spec.

There are some crap fuel pumps out there so be warned.

Check fuel pressure.

Did you buy plugs off eBay?

Leaking headers?

Fuel injectors could be a bit average. There’s lots of things.

Have you plugged it in to a scan tool?

 

[Immortality]

Fuel injectors would be my guess if it was predominately run on lpg.

 

[crewmen86]

Fuel injectors would be my guess if it was predominately run on lpg.

If I replace then do I need to have it returned?

 

[Immortality]

If the same injectors are used then no.

You could pull them out and send them away to get cleaned/tested.

 

[crewmen86]

If the same injectors are used then no.

You could pull them out and send them away to get cleaned/tested

 

[crewmen86]

They run around 28lb? Standard

 

[Immortality]

Unsure TBH. Just beware that there are many fakes on ebay and other online shops.

A fuel pressure check won't hurt either.

 

[Fu Manchu]

They could easily be a bit gummed up having had limited use while it’s been running on gas. It’s also possible the fuel pump is too. Drop some Liquimoly injector cleaner in and see how you go. You might get lucky but I’d bet the injectors need to sent off for a clean.