ashtray

iTrader: (12)

Hello, Forum

So today I turned on my car to move it so that my mom could move her Suburban out of the drive way while I'm visiting them. I go to re-park the car and when I turn it off and remove the key, the motor sounded like it was trying to keep itself running and it sounded like a cammed diesel truck(Motor wise, not exhaust). It lasted for about 20-30 seconds and the entire time I'm freaking out because the car is shaking like crazy and nothing I did could stop it.

After it stopped I turned it on again and let it warm all the way up and when I turned it off this time, it didn't do it, and it acted normal.

Any ideas wth this could be caused by? I recently drove ~170 miles and she didn't hiccup even once. I'm very surprised by this.

Best,
Ashtray

eknine9

iTrader: (8)

How was it revving when you tried to turn it off. Were the RPM's hanging out at normal idle or were they all over the place?

For the record right now I have no clue what it could possibly be, just trying to get the ball rolling here.

HiPSI

iTrader: (2)

LOL^


I've never experienced this but after some research the term "dieseling" came up in wikipedia and it sounds like it describes what you experienced. There is a short period of time that the ECU is actually still powered until the power is cut, but this is maybe 5-10 seconds max.

http://en.wikipedia.org/wiki/Dieseling

http://www.badasscars.com/index.cfm/...prod/prd94.htm


But none of this makes sense because when the key is pulled, the ignition is cut off, which would cut any spark to the cylinders. Maybe the car got stuck in some weird limp mode / still power to the ecu (90's electronics gremlins).

Bflatsharp

iTrader: (18)

If it feels like starting the car, you're starter could be going bad.

eknine9

iTrader: (8)

Why would his starter cause his car to run extremely rough when he tries to turn the engine off?

ashtray

iTrader: (12)

It almost sounded as if the motor wasnt actually "running" but like if the pistons and everything rotational was still in motion but "dry" as in no fuel or spark was involved. The rpms were flat, nothing at all.

I did recently replace my starter because my other one had gone bad. This one is still giving me trouble, where when I go to turn the car on, the first crank will do NOTHING, not even tick once, and then the second turn of the key will start the car as if nothing. My battery is also new.

Bflatsharp

iTrader: (18)

The problem isn't running rough, it's the fact that after the key is pulled out of the ignition and it's still turning over the engine. I bet if you put the key back in and turn it to the start position it'll fire right up without skipping a beat.

Had this happen to me before. Exact same problems until one day it wouldn't start at all.

With the key out, the engine Isn't getting spark or fuel. However the starter is staying engaged and continuing to crank the motor.

eknine9

iTrader: (8)

Oh I get what you're saying now. do you think it means the starter is busted, or maybe just the wiring connected to the starter may be the issue? Or it even could be a problem with the internal windings of the starter itself.

Did replacing the starter fix that problem for you?

Bflatsharp

iTrader: (18)

If I had to guess, I would say starter solenoid. The part that actually pushes the rod/gear out.

I replaced the whole assembly. Never had a problem with it after that.

Of course you should always do a general check over first to be sure it's not something like a loose connection/broken wire.

ashtray

iTrader: (12)

I'll give it an eye balling if it gives me trouble again.

I'm putting my money on the starter.

Is there any possible motor damage?

Studiogeek

iTrader: (6)

Engine "run on" perhaps. Also referred to as "dieseling", i.e. ignition via compression only, sans electrical spark. Decent discussion HERE as well. This can be caused by excessive carbon build-up in the combustion chambers or on the piston tops which when hot, act like little glow plugs. This is common on engines that run rich or have oil burning problems. Sc's run quite rich. It is supposed to not happen with fuel injected cars because fuel should shut off but a damaged injector could dribble a bit.

Bflatsharp

iTrader: (18)

Only possible damage I would guess is to the flywheel/flex plate teeth if it cranks for too long. Spinning the engine gives it oil pressure, but how much I don't know.

SC400slide

iTrader: (11)

Sounds like the starter stuck for a little bit...I've seen older vehicles that haven't been started for awhile do this...

Ramblerman

Geek is more than likely correct as to what your car did, this sounds very much like a dieseling problem. Which means your injectors must be some what dirty & leaking a bit into the cylinders & must be some carbon build up on your pistons & valves. There are ways to remove carbon build up from the cylinders with out a tear down & some injector cleaner may help the injectors. Used to blow up exhaust systems by revving them up while they were dieseling then turning the key back on, back in the old days. Fills the mufflers full of raw gas. It can also damage the engine.

kartel876

sounds like a bad starter and solenoid man seen this happen a lot at work.