We have a 1969 Chevy C-10 pickup that cannot pass emissions. Too much CO at idle, most likely a timing/dwell issue. Anyhow, I cannot easily find tune up specs for it. Does anyone have this info? The engine is 100% stock and original (7,750 miles on the truck)

I should have them at home. Is it manual or auto trans, 2 or 4 bbl carb? As far as emissions, does AZ spec it on that truck? There were no requirements in '69, so I'm curious how they establish them.

Andy

QUOTE (andys @ Jul 22 2005, 02:35 PM)

I should have them at home. Is it manual or auto trans, 2 or 4 bbl carb? As far as emissions, does AZ spec it on that truck? There were no requirements in '69, so I'm curious how they establish them. Andy

Phoenix and Tucson metro areas require emissions testing on 1968 and later. 1969 350s had 28-32 deg dwell, .019 point gap, 4 deg advance (auto), and 600 rpm idle.

I think it is a 2bbl, haven't removed the air cleaner. Just read the original documentation on the truck. It has an automatic tranny.

There is a idle and loaded test that they run on the dyno. Everything does well except for idle CO. AZ goes back to 1967 for emissions testing.

It has a stumble when you get on the gas from a standstill. Going to replace the plug wires set the timing and dwell and see what that does for me.

Thanks for the specs Guy!


Is the timing set at idle, with the vacuum advanced disconnected and/or plugged?

QUOTE (Travis Neff @ Jul 22 2005, 03:46 PM)

Thanks for the specs Guy! Is the timing set at idle, with the vacuum advanced disconnected and/or plugged?

Yes...

OK, Next stoopid question. Where is spark plug #1? driver or passenger side front, or rear?

#1, drivers side front.
Drivers side front to back1,3,5,7
Pass side front to back 2,4,6,8
Firing order 1 8 4 3 6 5 7 2
Clockwise dist rotation.

QUOTE (Travis Neff @ Jul 22 2005, 03:44 PM)

There is a idle and loaded test that they run on the dyno.  Everything does well except for idle CO.  AZ goes back to 1967 for emissions testing. It has a stumble when you get on the gas from a standstill.  Going to replace the plug wires set the timing and dwell and see what that does for me.

If that carb has never been opened up after all these years, I bet you're overdue for a rebuild kit. That's probably a Rochester carb which are pretty easy to rebuild. The stumble could be from a dried-out seal on the accelerator pump valve. High CO can be caused by too high fuel level in the bowl. This can be from a mis-adjusted float setting, but I bet in your case, the float valve tip is deteriorated and letting too much gas get by. If you smell gas after you shut the engine off it probably a float problem. Another tip off is the idle mix screws don't adjust out right. By the way, the idle speed with automatic trans. is set with the car in drive, not park/neutral.

Yep it is a quadrajet 4bbl. I found a manifold vacuum hose that came loose that going to what looks like a soup can, that helped a bit. No more stumble.

Didn't know about the idle setting while in drive, that means I had it way too low.

No gas smell after the car shuts off, but I'll betcha that carb needs attention.

QUOTE (Travis Neff @ Jul 22 2005, 10:14 PM)

Yep it is a quadrajet 4bbl.  I found a manifold vacuum hose that came loose that going to what looks like a soup can, that helped a bit.  No more stumble.   Didn't know about the idle setting while in drive, that means I had it way too low.   No gas smell after the car shuts off, but I'll betcha that carb needs attention.

Well that can 'hose' you up. If you have a vacuum gauge might be worth giving it a check. 17-22 in. steady. I think the '69 350 4bbl was rated at 300 HP. Must be a nice truck. How about posting a picture of it up here?

That 'soup can' really looks like a tin can. For storing vacuum for the A/C controls and valves. Does it have working A/C? I had the 'soup can' develop a stress crack at the solder joint and cause a vacuum leak.

I think this one is a 250 or 240 horse unit from the owners manual. It doesn't look new on the outside. It has had a camper on it since day one and the only mileage was one some family vacations. We got rid of the camper a few weeks ago. Otherwise it was outside for all that time. The interior looks new, the bed looks new as well. I'll post some pics tomorrow.