engine won't stop

[69gmcbigblock]

hey all,

so my truck suddenly does not want to stop. so today i picked up a new ignition switch and installed it. plugged it all in and the same thing. it starts up fine, just won't stop when i switch to off.

it doesn't sounds like deiseling, but i guess it could be. it just keeps running if nothing has happened. the only other odd thing is that around the same time it started happening i got a nasty exhaust leak or something because it is suddenly really loud...but i've yet to find the big rust hole i expected to find.

any ideas?

cheers
droo

[Mordachai]

check your pcv valve

[fearnatine13]

i had the same problem about 2 years ago, right after i first got my truck. the valve cover gaskets were all bad, and i was losing oil on the passenger side over the manifold. apparently i had gotten so much oil on the starter, it shorted out and the truck wouldnt stop. doesnt quite sound like your problem, but just my .02 cents worth.

[69gmcbigblock]

Originally Posted by Mordachai

check your pcv valve

i'm not sure it has a pcv valve. it's a 69' big block and the only thing i see in the plumbing looks like a soup can with 2 hoses going to it, which looks more like a charcoal canister or something. any idea where it would be if it had one? i really couldn't find it.

cheers
droo

[RSRXION]

Your problem lies with the ignition and/or fuel. Back the timing off a couple of degrees and I'll bet your trouble goes away. You may not be able to hear the pinging found with a detonation or "spark knock" situation but you are certainly doing the valve seats and psitons no good whatsoever. You probably ought to look in to a little higher octane fuel as well if you decide not to change the timing. With the warmer temps and poor quality of fuel, detonation is prevalent and almost certainly what's going on. JMHO, Dean

[69gmcbigblock]

Originally Posted by RSRXION

Your problem lies with the ignition and/or fuel. Back the timing off a couple of degrees and I'll bet your trouble goes away. You may not be able to hear the pinging found with a detonation or "spark knock" situation but you are certainly doing the valve seats and psitons no good whatsoever. You probably ought to look in to a little higher octane fuel as well if you decide not to change the timing. With the warmer temps and poor quality of fuel, detonation is prevalent and almost certainly what's going on. JMHO, Dean

i dunno, i'll give it a go. for backing off the timing i assume it's just a twist of the dizzy? which way?

sorry, this is my dump runner truck, and i've been too cheap to buy a workshop manual =)

[dwaite72lnghrn]

It really sounds lile the starter selonoid is shorting the starting circuit. Check the exhaust where it connects to the passenger side manifold. If the leak is there it could have over heated the selonoid. Too much fuel would cause the BBC to shake and studder but with no electric to sparks it will eventually stop. My bet is shorted power to Dizzy it will just leep running.

[Huck]

Turn it off while in gear--does it now stop?

[Fastrucken]

try disconnecting the plug on your alternator. Some times the ignition can be supplied with just enough power from the field of your alternator to keep it running with out the ignition switch on. A simple diode would fix this problem.

Graham

[RSRXION]

Back to the previous post... If you shut the truck off in gear with the engine running, does it die ? If so I'll stick to my original assumption of too much advance timing. All of the other answers are certainly very viable and could be your problem. I'd start with the timing first because it's simple to fix and doesn't cost anything. Good luck, Dean

[69gmcbigblock]

Originally Posted by RSRXION

Back to the previous post... If you shut the truck off in gear with the engine running, does it die ? If so I'll stick to my original assumption of too much advance timing. All of the other answers are certainly very viable and could be your problem. I'd start with the timing first because it's simple to fix and doesn't cost anything. Good luck, Dean

in gear it does not stop. i have to stall the truck out to stop it. haven't had a chance to rotate the dizzy yet.

[john]

Originally Posted by Fastrucken

try disconnecting the plug on your alternator. Some times the ignition can be supplied with just enough power from the field of your alternator to keep it running with out the ignition switch on. A simple diode would fix this problem.

Graham

Have you tried this yet. I have seen this happen.

[69gmcbigblock]

Originally Posted by john

Have you tried this yet. I have seen this happen.

not yet, which plug? and if i were to put in a diode, what diode and where?

thx

[RSRXION]

what do you mean when you say you " have to stall the truck out " ? It's running , in gear and you shut the switch off and it dies ? My money says it's timing if this is the case. Dean

[69gmcbigblock]

Originally Posted by RSRXION

what do you mean when you say you " have to stall the truck out " ? It's running , in gear and you shut the switch off and it dies ? My money says it's timing if this is the case. Dean

errr, no.

it's a manual 4 on the floor and if it's in gear and my foot is pressing on the clutch it will not die when i shut the switch off. if it's in gear, foot off the clutch, and the truck is moving, or in 1st, it will not die when i shut the switch off (it will keep going or start going).

when it dies in gear it has nothing to do with switching the ignition. i come to a stop, put it in 2nd let off the clutch while holding the brake, and then it stalls out.

i tried pulling the plug on the alternator, that did nothing. i tried to turn the dizzy, but couldn't figure out where the heck you loosen it up...my engine bay is dark and dirty so it doesn't make it easy =)

[Longhorn Man]

do you have an electric fan by chance?

[69gmcbigblock]

Originally Posted by Longhorn Man

do you have an electric fan by chance?

nope, last i looked it looked like it was driven off the motor.

i think i may just throw in the towel and take it to a shop, since i know i don't want to fix the exaust problem, and i'd rather be working on my motorcycle =)

[Mordachai]

I don't know why I didn't think of it, but it certianly could be your timing.

There is a little piece of metal(bracket) attached to your intake (iirc) with a bolt, this bolt holds down a little metal tab or bracket that hold the Dist. in place. Loosen this bolt and you'll be able to rotate the dist.

I know this is a picture of a furd dist. ( right now I'm not where my truck is...)

but the tab will look something like this:


but will be on the back of your engine(durn furds) and as you said, might be under a bit of greasy oily sludge!

I'd reccomend getting a timing light, for only a little money, it can save you lots of headaches!

|M|

[Longhorn Man]

Many of you are thinking it is dieseling, but in fact, it sounds to me like it is still running like normal.
Unplug the ignition switch on the back side of the dash. You'll probably need a small screwdriver, maybe even 2. It is somewhat common for the terminals to get all messed up and arc across. There is a chance that your problem is in there, if it all looks good, i would replace the ignition switch.

[jay6891]

Turn the radio on! I had a 71 burb that for some reason that if the radio was off and I tried to turn the engine off, just kept running. If I turned the radio on and killed it, everytime normal. I traced wires many times and never did find the problem. Even unpluged the radio, yes I had to plug it back in to kill my truck.

[bryanw1968]

Hmm....
I had the same problem on my '68 in highschool and it was in fact the ignition switch. I agree that even though you replaced it, there could still be a wiring problem causing this. It would have to be quite of bit of dieseling to make the truck take off in 1st gear. Also, if it were a timing problem. Wouldn't you want to advance the timing? After all, isn't diesel combustion without spark? It's been my experience that my truck would only diesel if it was to retarded. Then again, I could be wrong. Just my .2 cents. Good luck!

[Longhorn Man]

advancing causes dieseling.
And the engine actually runs backwards when it does that, so when he lets out the clutch in first, he'd go backwards.

[69gmcbigblock]

well, get this, i took it to a shop, they spent two hours trying to figure it out then then called and told me it was the switch, i told them i had just replaced it and i was about 99.99999% sure it was not the switch. at that point they said, well we'll only bill you an hour, we can't figure it out.

so i get the truck, go to home depot to get some stuff, crawl under the truck since the parking lot is much nicer than my gravel driveway, and staring right at me is the battery cable going to the starter which has worked it's way loose and is firmly resting on the post for the little yellow wire. along with that is the hole in my exhaust manifold...pointing right at the starter...which i had also just replaced like 3 months ago...doh!

so it turns out my louder exhaust and non-stopping symptoms are related. the shop had figured out the manifold leak, but wanted $1200 to fix it and my rusty exhaust. i don't really care about the rest of the exhaust, but they wanted $500 for just the manifold part! which seemed a bit steep to me, considering this one is $90...

http://www.manestruckparts.com/store...Category_ID=26

anyway, once again the "professionals" have left me with a bad impression. i guess if you can't plug a computer into it and get a diagnostic code, it's just too "hard" to figure out.

thanks for everyones help. the first time i looked under at the start i just didn't see it. since i thought i was looking at a cheap exhaust fix i thought it would be something simple a shop could fix...guess i over estimated them.

if anyone has a clean passenger side manifold that would fit a 69' 396 big block, drop me a line.

cheers
droo