2f dieseling (1 Viewer)

[inzel]

My 2f motor will have a small amount of run on most times I drive it and turn it off. About one second after turning off the key. Sometimes it is very slight and other times it goes for a second or two and then there is a fairly big hiss type sound before it stops. Is there a common cause of this with a 2f that I should look at first or just go thru all the usual suspects?

 

[charliemeyer007]

Sounds like carbon fouling to me. How do the plugs look?

 

[pjohnson]

Check your timing also.

 

[mattressking]

1. Set timing to 7*
2. Clean, gap spark plugs.
3. Perform lean drop on carb. Verify what brand of carb is used. This dictates a few steps.

 

[inzel]

Ok sounds like the usual suspects then. I just pulled the plugs and they were pretty black so I cleaned them and put them back in. This truck sat for nearly two years so Im not surprised there are things to tinker with. Here are a couple pics of the carb and distributor. Seems like someone did some vacuum line delete mods lol. Should they be done correctly?

 

[inzel]

One other question I have is if it is normal to hearing a hissing sound from the carb when giving gas. I dont hear it at idle. Seems like a vacuum leak to me but Im no pro…

 

[45Dougal]

Second photo looks like your vacuum advance diaphragm is not connected!?
I'd expect it to be utterly gutless under acceleration?
Maybe someone adjusted the timing to be midway between idle and load in order to get it moving, so check your timing.
Sounds like the other end of the pipe is also left open if it's hissing.

This should be a rewarding fix - the cost of that missing pipe should make a big difference.

 

[mattressking]

Aftermarket carb (not preferred as you need to find out the jetting and overall condition). The circled gas filter (vacuum ports) are looped with a piece of vac hose so that’s fine unless the hose or filter has an active leak. The advance on the dizzy doesn’t need to be connected. It will drive just fine, just won’t advance. That said you need to connect direct to the ported vacuum on carb - otherwise don’t connect to any other vacuum source.

Hook a vacuum gauge up at idle to a manifold hose barb and measure. Needs to be a minimum of 18inHg at idle when warm, at sea level. Subtract 1inHg per 1k ft of elevation.

Then find out exactly what carb that is, do a lean drop and see how it reacts. You’re better off getting an oem carb but for now you could get it going by getting the vacuum healthy, clean and correct plugs gapped and verifying the existing carb functionality. If it were oem there’s a list of things to go through but that’s not the case here.

 

[inzel]

All in all it drives well and has power. Starts right up every time on first click, idles perfect, doesnt get hot. I will still check all those things tho