Engine bogg

[Foosified]

I've done a search on other threads and while informative I don't think the answer to my problem was mentioned.

Here goes; I have had this 71 c10 for 4 months. I have replaced the engine with a rebuilt 350 (1981 I think). The previous owner had HEI ignition installed. I have not replaced the cap and rotor yet, but plan to. plugs and wires are new. Have not checked the condition of the plugs yet. There is less than 1000 km on the engine.

when installing the new starter there were three wires. One for the power, one (purple i think) about 16 gauge for ignition and a 20 or so gauge yellow wire, which I believe was for the original ignition system with points. Do I need the yellow wire??

Back to the bogging down. Runs fine when cold, but once running at operating temp. the symptom occurs. I press on the accelerator for a modest acceleration... normal acceleration?? Not flooring it... and it will sometimes bog so bad it stalls. Other times it will bog and then accelerate like nothing happened. Recently I was accelerating and it was switching between bogging then running fine continuously for about 4 blocks??

Things that have been left constant between the original engine and the new engine are the transmission and HEI ignition.

The new are the plugs, wires, 1406 edelbrock carb, starter, fuel line with in line fuel filter (which is clear).

I had similar symptoms with the other engine prior to engine swap, which led me to believe there was something wrong with the transmission, but I don't think that is my issue, as it makes no weird noises and shifts fine.

One last thing. When I first got the truck I parked it over night and tried to start it the next morning... it would not fire. I ended up cleaning the cap and rotor and the thing fired. This was after a couple of days trying to figure out what the problem was??

So I think my cap and rotor definitely need to be replaced. I am curious about the distributor getting the proper voltage.

Do you have any suggestions and am I on the right track??

It is properly timed also.


Thanks

[RACINJASON22]

For the price, replace the cap and rotor just to eliminate them from the equation. Go from there. RJ22

[neonlarry]

you can eliminate the yellow wire. Also make sure the other power wire to the HEI is not the original resistance wire or you will not have the full 12V to the HEI.
Some thing to try as far as the boog:

by Lars Grimsrud
Tech Tip #3
How can you tell if an off-idle stumble is caused by a lean or a rich condition?
A carb running rich, as well as a carb running lean, can cause an off-idle stumble or hesitation upon acceleration. To narrow it down, tap the roll pin out of the accelerator pump lever by using a small pin punch or a small finish nail. I actually use a small, broken drill bit that's just the right size. Using a hammer, gently tap the roll pin in towards the choke air horn wall. Don't jam the pin right up against the wall: Leave just a little bit of a gap so you can get a screwdriver blade in between the wall and the pin to pry it back again. With the pin tapped out, remove the accelerator pump lever. I like to do this with the engine running so I won't have any trouble starting the engine without the accelerator pump. Now, rev the engine a little with the throttle. Notice if the engine seems quicker and more responsive, or if the hesitation & stumble is worse. If the engine actually feels more responsive with the accelerator pump disconnected, you have a rich condition. If the hesitation is worse than before, you have a lean condition. If there is no change whatsoever, you have a non-functional accelerator pump.

To verify a suspected lean condition after this test, simply hold your cupped hand lightly over the choke air horn area with the engine running at idle, restricting the air flow. If the idle speed and idle quality momentarily increases, you have a verified lean condition. You need to select a jet/rod combination that will give you a little more Cruise Metering Area. Make these changes in less than 10% increments using the Figures provided in this paper.

This is for a Q-Jet not an EdleJunk so you will have to find how to disconnect the accelerator pump.

[Lemield]

Just my 2 cents worth....

Every Edelbrock I've ever owned has had a bad to a mild off-idle stumble. I've dorked around with the accelerator pump but that never seems to help. What finally solved it was putting in a heavier metering rod spring. Edelbrock sells the metering spring assortment. Worked for me. Good luck.