Dreaded intake manifold leak...I think?

[tinfoil_hat]

Did you mark both the rotor position and the dist. housing poisition?

 

[east302]

Any codes (P1345)? Did you reset the CMP Retard following distributor reinstallation?

Does it idle rough like a vacuum leak? Could be the ring gasket around the injector connection going through the upper intake was dislodged. Spray carb cleaner around it and see if it stabilizes.

 

[Byard]

@tinfoil - yes marked dist. base and rotor location. When I inserted it back in it was a little off the mark, so I raised up and moved till it inserted on the mark.

@east302 - no I haven't checked with any type of code reader, and yes it does seem like a vacuum leak. I've sprayed starting fluid all around intake with no notice of engine change.

 

[Byard]

Also thanks for the help replies

 

[east302]

You would need to set the distributor CMP offset using a scanner if you haven’t already done so. Spec is 0 degrees (plus or minus 2) at 1000-rpm.

 

[Byard]

Thanks east302

I went back and watched the YouTube video I went by and he did mention having to set the distributor CMP, but didn't show how to do it.

I will try and find someone who has a scan tool and check it.

I sure hope that's wha t it is. I done a lot of wrenching in my 50 years just not a lot of distributor or timing stuff.

Thanks

 

[Byard]

Update: had a guy with a scanner tool check my truck yesterday. Showed not firing on #5, #7 and timing about 5 degrees off. Got timing in spec but still skipping.

All spark plugs were changed at time skip was first noticed as I pulled them to check there condition. Using a old plug we checked for spark at each plug wire...all 8 are getting fire to plug. Changed distributor cap and button and still has the same skip.
I pulled #5 & #7 plugs and they were wet and smelled of gas, so it seems they are getting gas.


He's going to come back and try something else I guess.

 

[mckee1710]

Did both the gaskets and the MPFI swap today. Old gaskets were toast, cracked in multiple places around the rear coolant passages. No signs of leakage internally though. Overall the job wasn’t bad, just time consuming.

I used the pinned “intake gasket replacement” thread and the 1A auto YouTube video for guidance, both very helpful. I used some 5/16” x 3” threaded studs to align the manifold when reinstalling, worked perfect.

Truck runs noticeably stronger and smoother with the MPFI spider, although my stock CFI unit looked pretty good. Glad I decided to do it while I was in there.

 

[Byard]

Well, just because I hate reading about other people's problems and never seeing where they post what solved the problem they were having, I will post what solved mine.

The guy working on my truck had it for several months ( although he didn't work on it the entire time he had it, just when he had time to tinker on it )and tried several diagnostic test. Checked for vacuum leaks, firing issues, compression test and finally narrowed it down to fuel issue. we replace the spider injectors with a new set and my misfire on cylinder #5 is solved. Only parts thrown at it were 8 new spark plugs, distributor cap and rotor button and it really needed the plugs anyway. 182,000 mile and runs great.

 

[tinfoil_hat]

Just getting ready to do the gaskets for the second time in 4 years. Think I will do the MPFI upgrade and dizzy while I am in there. Hopefully it goes faster this time.

What are the current prices for having a mechanic do the work?