Sho Idles Alittle After Shuting Off!

[1995SHO9]

On my 91 beater SHO, it just started idleing after I shut it off. I will turn the key off and it will almost die, go up to 500rpms and then shut off. Any idea's guy's?

 

[jthod]

 

[1993MTXSHO]

sounds like you got a case of the diesels haha. This happens a lot with old cars more then new, but its called run on or something. Your car might have some bad carbon deposits that are creating hot spots and when you turn the car off it actually ignites fuel again a few times (aka running like a diesel). I believe it is usually caused by timing being off or something but I could be way off. I forgot a lot about this I'v been out of carbed engines for a while. The only weird thing is that new cars have electronic fuel injection which should turn off the injectors when you turn the key off so I don't know what else to really say.

 

[1995SHO9]

Time to bother Brian. Damb car won't communicate with his fancy spancy computer.......

 

[hawkeye18]

I've got a fever... and the only prescription is...

MORE COWBELL!

ahh... but seriously now.

Sounds like you got leeeeaky injectors, or like 1993MTXSHO said, bad carbon deposits.

Try running a can of seafoam through the intake (suck it in with one of the vacuum lines on the TB) and see if that fixes it.

If that fails, test your fuel PSI with the engine running, then turn it off. If pressure goes down at all within about 10-15 seconds, you got leaky injectors.

 

[1995SHO9]

Will do.

I've never delt with this before, can I keep driving the car without it hurting anything, I don't think it would.

 

[1993MTXSHO]

na you should be fine, my buddys truck does it all the time, it wont really hurt anything.

oh and Id be careful trying to clean it out, by careful I mean leave it alone IMO, and if you do decide to do it, you need to take the catback down and have a gutted y pipe on it. Otherwise you will get chunks of carbon stuck between the converter and engine. But id be more worried about big chunks of carbon jamming a valve open or something, although it is probably uncommon.

 

[haydenkayne]

hey 1995, hows that boost treating you?

 

[1995SHO9]

hey 1995, hows that boost treating you?

Eh, I had problems with fuel injectors and some other craic, now I got the accel 48's that are slated to go in soon.

I still need to get a dead on tune, Toolman mentioned he is going to be in PA and would probably stop by the end of this month to help me out. That would be so awesome because number 1 I've heard he is a really cool guy, 2 I'd like to meet him and 3 I am lost on the tweecr....

Thanks for asking.

 

[haydenkayne]

i really enjoyed that thread of your boost in progress. i hope to be able to do that next year myself. eventually id love to get to a sho gathering, you guys all seem real cool. good luck with the car and and the law, try to keep the needle outside of the km/h area

 

[Kens1992mtxSHO]

Screw the seafoam, put some BG induction cleaner in it. It'll clear those carbon deposits right up.

Take the manifold off to do this.