So every half a dozen or so times i turn my truck off it does this surge thing where it seems like its trying to start back up or continue to idle, and it lasts for a few seconds then eventually stops. Anyone know what this could be? My friend said it was probably the timing but I dont know anything about timing so I dont know how to tell. Very appreciative of any help or advice!

 

oh, and its an 83 4x4 with a 22r incase it matters

 

Usually bad gas, low octane or timing is out of adjustment.

 

Dieseling?

 

x2. just on this tank? my buddy filled up with a REALLY bad tank and it idled, accelerated (and dieseled a little bit) all really shaky, felt like bad timing.

 

Well should have a look at the fuel shut off solenoid. My old 82 would do this when shut off because the solenoid had a little oring to seal it but it had broken. Put in a solenoid from the 80 and she shuts off nicely.

 

I dont think its bad gas because I have had it long enough to have put a few different tanks in and it has done it before. I just filled up so I'll see if it happens. I am thinking it is my timing. The truck normally idles nicely right at 1000 but once or twice it has had a low puttery idle and it seems to shake a little when i shut the engine off and I think thats linked to the surging because the truck gets really shakey while its doing it.

 

I think you should check your solenoid valve. Its on the carb. Got a red and black wire going to it. Might do wonders.

 

its dieseling.

does it only do it when parked off-camber?

i'd start with the timing, also check your mixture.

Al

 

absolutly .. dieseling !

 

More than likely, its a timing problem. Replace with OEM spark plugs, and set timing to specs (Canadian non-emissions?). I say replace the spark plugs, because certain spark plugs range in max. heat temperature. Basically, too hot a spark plug can retain heat and operate as a half-assed ignitor. More than likely, its the timing.

I would understand why it might be the fuel cut solenoid, but my arguement is that my 67chevy truck didn't have one of those... anda little timing adjustment stopped IT from dieseling. Bad gas wouldn't do this. If anything, it'd resist dieseling... bad gas sucks. It loses its combustibility.

 

Perhaps check your starter. Sometimes my dads truck would try to keep running even after it was shut off due to the starter solenoid sticking

 

its dieseling. most likely carburetor related. there is some type of fuel cut system to prevent it, id research that a little

 

I think your on the right track. Think glow plug.
This condition is often called dieseling or run on. Normally when you turn the key off, it kills power to the ignition. On the Toyotas(with carbs), there is a fuel shut off solenoid effectively cutting off fuel supply at the carb.
A internal combustion engine needs 3 things to run.
Air
Fuel
Spark
So, when you turn your key off, the engine is supposed to lose 2 out of the 3 links in the chain(fuel and spark).
WTF right??
My guess is that the fuel shut off solenoid is bad. The spark could be from a hot sparkplug tip caused by a overheated engine or a very lean mix together with compression heat.
Until you fix this just let the clutch out with it in gear(manual) or shut it off in gear(auto).
Note: with a bad fuel shut off solenoid, gas might drip into the manifold causing a hard start or flooded condition when the engine is warm.

 

Wow ok well I think thats all the advice I need thanks alot guys. Ill try the plugs and solenoid and if its not that ill assume timing.

 

Can you explain to me how ignition timing can cause dieseling?
The only thing I can think of is that the wrong timing causes the plug tips to get hotter.

 

so you are saying these motors don't kill the spark when the ignition is off, just fuel?

learn something new every day!

Al

 

Thats not what I said at all. C'mon Al, your smarter than that.
"Normally" was a poor choice of words. I said that because there ale always exceptions to the rule.

 

you are starting to sound like my mother!!

Al

 

carbon build up in the cylinders can cause it to diesal too... and detonate