well the mechanic scanned the truck and he says he cant find reading on throttle position sensor and egr then all of a sudden they would be there then gone again. also says the truck runs and drives great on the highway but just wont stay idle. has trouble under the 1000 rpm, he took vac hose off the brake booster and it would idle but not great, so he is leaning towards a valve issue, not enough vacuum. I did reuse the valves from motor but lapped them into place and they seemed to seat properly. that being said I did a leak test on the cylinders, got thru the first three cylinders and the air is seeping out of the oil filler. so must be rings?!!?. I never heard anything out of the throttle body or exhaust. my question is if the rings haven't seated properly will it cause it to not idle? the rings were proper fitting rings for the motor and I checked it out too when installing. had the manual with me making sure ring gaps were all in right spots. the motor has only been ran maybe a total of 30-45 min and rarely under load.

 

What are the compression reading on each cylinder? Is #8 now firing? You had an issue with it before but never said if you bad it corrected and resolved

 

I kinda hacked up my compression tester to make an adapter to leak test the cylinders, so I will have to pick another one up and test compression. I still don't know if #8 is an issue, as I pulled the other plugs out on 1,2 and 4 they all are just black and still got fuel on them. the mechanic out here says his diagnostic machine is kind of old technology and hes getting a newer better one this week, so that might help.

 

did u ever figur it out because I’m having same exact issues same cam swap also

 

He hasn't been here in 7 years.......

 

I got it custom tuned through hemifever. And that fixed all my issues

 

Wow.

Thank You for dropping in with the answer.

 

Well that's a first lol

 

Quite literally the first time I've seen it happen lol.

 

2nd for me. In 11 years......