The Stovebolt Site Forums The Shop Area Engine Shop Second....all not smooth sailing yet....engine still rough

Ok, with help from KC people the 65 C30 is at least running again.

Unfortunatly, I think that all the varnished gas that was run through the engine (newbie mistake) has done more than just foul the carb up.

Took the truck out on a decent run this evening and I will list the things in order they happened....

1) In third gear, at steady throttle, she surges just a bit. A little of that hesitation that I am starting to hate comes through. (Put her up into fourth and she seems to smooth out a bit.)

2) Tried to down shift as I approached a stop sign...from fourth to third. (Done this many times on other manuals.) She bucked and backfired. That was a suprise as she never did that on the test drive the day I purchased her.

3) Later as I let the engine take her weight on a down hill, the same thing. I clutched to avoid more backfire.

4) More hesitation and surging in third gear at steady pace, so had her in fourth at 25-30mph

5) Then I took her out on highway and up around 60 she does the same hesitation/surge in fourth

6) Then as I took my foot of accelerator for a car that was slowing ahead of me, she backfired as the engine started to slow her down. (I clutched and took out of gear at that point.)

7) (Unrelated to above, I think) She sounded like she blew an exahust gasket or something about that time as now I hear exhaust right up in engine compartment and not under seat like I did. (Dark now, haven't looked to see.)

So...all of that. I am thinking there is more of this nasty tan gook crud burnt up or plugging something? (This is the stuff that was pulled out on sending unit, was in gas, and was cleaned from carb.) She idles fine still. Wrenchbender said that the engine sounded fine and I was just being fussy about the tapping noise.

Am I looking at major surgery here? Or is there something I am not aware of...(which is most likely).

Dave

The surging can be caused by over-advanced ignition timing. You could try reducing the advance slightly to see if it helps. Mark where it is now so you can put it back if no improvement. If you mean your exhaust is popping on decelleration, that usually means the exhaust gasket has failed or the head pipe isn't tight.

Yes, that is what she did three times. Now I know for a fact that there was no seal between the exhaust header and the exhaust pipe...once there had been some kind of high temp wrap in there, but that came out.

I can't cinche that up anymore as the bolts in the exhaust header flange are stripped of thread about half way up. Those bolts will need to be drilled out or something.

As for the advance, we are just talking timing at the distributor...right? I can fiddle with that just by rotating the cap a bit...right? (That's easy enough.)

Dave.

The backfires cacan sure come from the blown out exhaust gasket. The leak allows fresh oxygen in the system and it combined with the heat fires off. Get the manifold fixed before going any further. You most likely need a carb rebuild, the surging souunds like a bit of overfueling. Check the sparkplug color. The overfueling could have caused the first backfire that caused the exhaust leak! A lean mixture can also cause a surge, junk in the carb may be blocking a fuel port, so again, a rebuild is needed. Joe

Dave, Have you taken a compression check on the engine?

No, no compression check yet, my neighbor says that he has a compression tool that I can borrow.

I'll get around to that this weekend just to have the data.

But it sounds like I will be pulling all the manifolds this weekend too. There are definitly gasket and sealing issues there. Thought I could deal with it later, but guess not.

Where can I get some of this PB Blaster that everyone is talking about? Want to lube up the bolts and everthing before I start wrenching.

(Oh, and to Joe's point, Wrenchbender helped me with the carb this past weekend. It is rebuilt and clean....he said he cleaned out a bunch of the same crude that was in the old fuel system.)

I,m with Baldy. I think you have too much timing. If you don,t have a timing light set it back a little & try it. Your plugs are probably carboned up from dirty gas, over rich mixture or excessive idling. You might have to take them out & clean them.

Hey Sablesurfer, my exhaust manifold studs were stripped too. I couldn't get the nuts tight enough to seal the joint with a donut. I cut the studs down enough with a grinder, and welded some new thread in its place. Works good now. Just wanted to say more than one way to skin a cat, go with whats comfortable for you. LOL

Hey Truckstein....I am starting to believe more and more that I am just going to have to learn to weld. Need to weld for body, need to weld for engine parts, need to weld to put in seatbelts....sheesh.

Anyway, the exhaust manifold is at the shop today. Unfortunatly, the dude the does the bolt removing isn't in till Monday (whatever that means).

I have the new gaskets...the old ones were blown out in two places...one up by the block and one inbetween the intake and exhaust.

Once those are all back in then work on the timing and take some compression measurements.

Dave