When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I got this car ab 2 months ago and it hasn’t ran right since I got it. It runs like it’s starving for fuel and the fuel pump eventually went out and I changed it and it made no difference. I checked the timing and it Was right. I dropped the gas tank and checked the sock filter and changed the rubber lines back there and everything looked fine back there so I decided to tune it up since I hadn’t yet and it’s always a good place to start. The plug gap listed under the hood is .080 which seemed crazy to me so I checked the forum and some users said to go w .045 so that’s what i did but now the car won’t stay running unless u have ur foot on the gas. It will idle for a second and then die. Do u think this is bc of the spark gap or a perpetuation of my fuel problem I been having? The car idled fine before it was sluggish up hills and at speeds above 45
Sounds to me you have a fairly decent air leak somewhere. Check carb bolt tightness, inspect all vacuum hoses for integrity/tightness. Also check the canister control vacuum lines/switch/diaphragm (front passenger side of engine).
That's just a start. There may be more issues, but if you do a tuneup, check timing, and get any vacuum line issues found/fixed, you may find it solves the issue. Or something further may need to be done.
The .080" gap was found to be too wide and later they changed it to 0.060" but your .045" is better. They opened up the gap because of the lean-*** fuel mixtures they put with these cars, and it overstrained the HEI systems and stuff started frying out in them. Smaller gaps pose no issues and saves your HEI.
Sounds to me you have a fairly decent air leak somewhere. Check carb bolt tightness, inspect all vacuum hoses for integrity/tightness. Also check the canister control vacuum lines/switch/diaphragm (front passenger side of engine).
That's just a start. There may be more issues, but if you do a tuneup, check timing, and get any vacuum line issues found/fixed, you may find it solves the issue. Or something further may need to be done.
The .080" gap was found to be too wide and later they changed it to 0.060" but your .045" is better. They opened up the gap because of the lean-*** fuel mixtures they put with these cars, and it overstrained the HEI systems and stuff started frying out in them. Smaller gaps pose no issues and saves your HEI.
I found one vacuum line that was rotted out and I fixed it but there probably are more
how would u go ab checking the switch and diaphragm on the canister?
I finally have a copy of the chassis service manual coming so hopefully that helps me too
Diaphragm on the canister control vent valve (little round black plastic valve canister) can be checked by hooking a vacuum line up to the top chamber and seeing if it leaks or not. They're notorious for the diaphragms crapping out on them causing air leaks.
The TVS valve should be ok if its intact, but it's spring loaded and the glue on the lids give way and pops the unit apart like a jack in the box. HUGE vacuum leak from that. If the lid's still on it, you should be ok with the TVS.
All that stuff is hidden in the front of the engine so it may be a bit tough to get to.
TVS (red, orange, or black cap):
Canister control valve:
Kinda what it's supposed to do when engine is warmed and running:
Get a can of brake clean. Spray it lightly around the base of the carb, along the hoses,
and thermo vacuum switches. If you have a leak the engine will rev up. Pull the PCV
loose and shoot some in there. It will rev up; that shows you what to be listening for.
It should run just fine at .045", I usually go with just a touch over that. Did you change anything else? The plug wires may be toast and that could be the issue. You may have poor contact on the plug. Also double check the firing order.
January 5th, 2021, 06:23 PM
