Dieseling-need input pls

[GBowman]

Have about 400 mi on the new motor...for some reason it is running/dieseling after I shut it down-I would say 20% of the time. I lowered the idle to about 950-1000 RPM and checked timing which is 15/32. Yesterday the car was difficult to turn over, i pushed the starter button and it hesitated, then cranked over-almost like a hydro-lock situation, I don't see any fuel dipping when its shut off. Could the starter be shot with only 3,000 miles? Or are these two things related?

Thx

[jhv48]

Try reducing the idle and see if that cures it, 950 -1000 is pretty high for that engine. My 427 roush idles at 850 just fine. When I had it at 950, it ran on occasionally also.

A hesitant starter can be either a low battery, weak starter, poor ground or too much (or too little) initial timing. Your numbers seem fine, but try backing off the initial timing a few degrees and see if that helps. If not, try advancing it and see if that does it. If no change, then have the battery checked.

[cobra 53]

Same problem on my 302.

After changing Plugs and Idling adjustments it was an bit better. Bud with hot engine it was still daer. I ordered a Timeligth und found the Timingpoint at 12-14 / 30-32. Adjusted to 18/36-38 and problen was gon.

Rico

[GBowman]

Hmmmm...I figured retarding a bit would be best. Hopefully, lowering the idle a bit more will work-we will see.

[Cashburn]

We think timing. Don't think it's where you think. Check that again.

[Grubby]

I say too much of the carb transfer slots are showing.

I would remove the carb and check. You might be able to open the secondaries some to allow closing the primaries some. In addition, if you have a rough enough cam to idle that fast it might be needed to drill a small hole in each of the primary butterflys to allow you to close them further.

John

[Cashburn]

Are you using the correct set of timing marks on the balancer?

[Gaz64]

If you are happy with your timing, my suggestion is to add an anti-dieseling solenoid to the carburettor.

You can then have a normal idle speed of 950 and 700-750 with the solenoid de-energized.
The primary closing off to the 700-750 rpm point should stop the run-on.

[GBowman]

Timing was off a few degrees (like Jay said I think we used the wrong mark initially)-reset it along with some carb adjustments and it seems way better at idle and so far no run on-havent had a chance to run it too much but Im feeling pretty good as it idles at 850 far better-before it just didnt sound/feel right and smelled too rich.

Now the new issue-I noticed that there was antifreeze leaking (just a small amount) from the freeze plug in front of #1-WTF??? Then noticed that the upper and lower hoses looked like they were going to explode and were really hard-and this was after the car sat overnight. I tested the cap, holds to 16#'s then realeases, my rad cap always has felt too hard to screw on to me. I backed the cap off a bit and the hoses are fine and no more leak. Has anyone had any issues with the puke tank/cap fit?

I am wondering if the cooling system being over-pressurized could have added to the whole situation? Could it create a difficulty in starting? I had a few starts that felt like the starter was bad or the batt was weak-it would take a second to turn over after I pushed the starter button.

[Gaz64]

Gary,

Sounds like your cap is stacking solid, possibly a mismatch with the radiator neck.

I'd also say your system is pressuring above 16 lb, when you say the hoses were really hard.

The cap pressure rating is always the weak link to prevent radiator and welch plug failures if a head gasket failure occurs.

Something to think about.

[andygay]

I am not sure how valid this is but came across a simular thread on a FF site. They stated that the cooling fan spinning down would act as a generator and would cause dieseling.