Rough idle and running rich

[kermit_rr]

Ok so smoke into the intake, into the cylinders, past the piston rings and back up the middle of the distributor? Possible?

 

[kermit_rr]

The 3.9 and the 4.0 have the same bore and stroke

 

[pwood999]

LR Marketing eh ? Never looked at that, but I see in RAVE both are 3950cc.

 

[marjon]

The 3.9 and the 4.0 have the same bore and stroke

LR Marketing eh ? Never looked at that, but I see in RAVE both are 3950cc.

Its my understanding that it changed to "4.0" when it went to serp belt and GEMS control.

But its the same engine, except the bla bla bla .
Like the 4.6 is the same as the 4.0 except for the, crank and the bla bla bla

J

 

[norseman]

Looking at the ecu codes the one that was fitted was from a 4.0 and the other one that I tried is 3.9 I must admit the 3.9 did smell a little less fumey but not had the chance to take it out on the road to test it properly. Compression seems ok but not perfect, lowest 155psi and highest 170. I’m just gathering the kit to do a leak down test this weekend to determine if I need to bite the bullet and pull it apart!

Beware mixing/matching different components, the basic engine design is essentially the same but some of the ancillaries are not.
3.5 distributors can have different part numbers for different model years, not just carb or efi variants.

nb. not a fan of PS components or their customer service, but that's just a personal opinion.