Thrird "is" a charm? (1 Viewer)

[Denofearth]

This is the third time I am having my 350 rebuilt, with less than 100 miles on the motor.
The motor was rebuilt by a reputable co. First no oil press. second slop in crank causing bottom to "fall out" and third now the # 7 cylinder seems after an extensive checking has no fuel going to it.
Now, background info. 350 TBI New brain. rebuilt 350.
Things that I have tried: switch plugs and wires. Checked compression 120 lbs. Check valves for overtighting (floating). Checked rotor for wear or bad spark (new) and when plug wire is left off while motor running spark is there ( I have felt every spark owwwee) The plug is dark, not wet?
Please if anyone has any good advice, I am at my wits end this engine swap was started last year Oct. YES!!! 14 months ago. I don't know about you but that is just too long not to be able to drive my baby.
Thanks Dennis

 

[bandy rooster]

hey bro, i'd ask this question on a hot rod forum - sure i bet some of the cheby guys could answer this but nearly everyone who hot rods knows about 350's. try posting up there, i'm sure theres a bunch of belly button engine techs there. sorry i don't have any good answers just trying to tell you where you might find them.

 

[Pin_Head]

Pull the throttle body and run a fish tape down the #7 runner and pull that shop rag out of the intake.

 

[Shawn Russell]

I had the same thing happen to me. I finally gave up and bought a GM crate motor. Will never buy a rebuild again!

Shawn

 

[andrewfarmer]

faulty lifter?
have you pulled the valve cover and checked both valves do the right thing when it's running?

Where on the manifold does your brake booster connect?

 

[Rice]

Not firing at all, sometimes, or firing but is weak? What tells you there is no fuel getting to #7? Does it clean up and run right at any RPM?

Start with the simple:

Change plug (again)
Change wire (again)
Change distributor cap (not the rotor button).
(remember, the ignition system showing spark outside the chamber doesn't really mean a whole lot. It's much harder to make a spark in the chamber where there is compression)

Then,
Check for proper lift at the valve (wiped out cam lobe or dead lifter)
For TBI fuel would not be absent from just one cylinder unless there was blockage (the shop rag theory) or a big vacuum leak at #7. That could result from an intake manifold gasket being screwed up. Time to pull intake and see.

 

[Denofearth]

OOHHH I guess I will have to take it back to HIM I did all of the things mentioned. The engine runs well except it rocks like a miss. I pulled the plug wire on #7 with no change in rpm, when I pull any other plug there is a very noticable drop in rpm.

 

[dmaddox]

Pull the throttle body and run a fish tape down the #7 runner and pull that shop rag out of the intake.

amen brother....

ragman

 

[Pin_Head]

amen brother....

ragman

I have seen a rag stuck more than once. I'm not saying who did it, but I will say that you tend to remember the things you learn the hard way.

Another possibility is that there is a vacuum leak on the #7 runner so that it won't fire at idle. Maybe a bad or mislocated intake gasket.

 

[Denofearth]

Thanks for the input (without sarcasm) I am really pissed at the installer. like I said this is the third time,...CAN'T YOU GET IT RIGHT !!!

I digress...........

I am going to try everything ya-ll (ha Texsas) have sugested. Then some,
I am going to first try new dist. cap then check all cylinders for comp. then go to valves for propper adj. then re set them accordingly, (is that worm or cold...does anyone know, I think it is warm)
If that does not show any results I will takt it back to him and tell him that he needs to take off the intake manifold and take that f-----g rag out of the intake on #7!!!!
Thanks once again...Your prayers are needed right now for someone....MMMMEEEEE!!!!!