Alright guys get this, Yesturday instead of just putting in 87 octain gas in my car, i put in a hole tank of the 89 octain gas, and i have no more decell after shutdown. Heres my reasoning for putting in the higher outain in my car.

Eversence i got the car running good, and pluged up all my vacume leaks, my car would continue to run on after shut down, Big old Knocks ect. Well, i was out looking for a job, and i know a guy who restores the classic mustangs (yea yea i know the dark side :P) so i went down to his shop, and asked him What could be wrong besides that it was a chevy, he said it could be because of timing (which i know its not) or it could be a Carb problem OR some one screwed with the compression, and he told me to put a higher octain in and see if that helps my problem, Guess what, 89 octain seems to be the charm for me So either some one screwed with my compression, OR i have a serious carb problem,

 

whatever works I guess.. I run 91 octane, anything less and I ping like a mother.

 

wow, thats weird cause it it keeps running ofter you turn the car off thats usually the carb(or fuel injector/s on a EFI car)

 

Thing is this is supposed to be a stock motor, and supposed to run on 87 octain... so, i have no clue what is going on with this engine, btw is there a fuse for the Cruise control somewhere? i have yet to locate it.

 

How sure are you that your timing is right?

Sounds like timing to me... Your motor would lose compression over the years if anything, not gain it.

If someone had the heads off the car at one point it shouldn't be too hard to find at least SOMETHING on the top end of the car to indicate that someones been down that far at least.

 

The thing is, i have no clue to what has been done to the engine, let alone the car, the lady who i bought it from said that she took it the "dealer" to get all the work done on it, and from all the dealers ive been to only one has a record of it and it was the one who sold her the car... is it possable a Cam swap could also be to blame? The timeing also checked out so.

 

If you set your timing to 0 tdc, you should be able to run 87 just fine. Mine is at 6 and runs ok on 87. I would be willing to bet that your timing is off. The carb or fuel injection will not cause detonation, unless it is running way to lean. If your computer is hooked up and that is happening, it is your timing.

Good luck.

 

I put up a Timeing light on the car, Timing was just fine, i changed out my o2 sensor, im not throwing any codes either, And it is a carbed car.

 

well 89 is going to stop knocking it has a cooler burn temperature and is more stable
as far ias the diseling or run on that can also be caused by carbon build up inside the motor which not only raises compression but ignites the fuel inside when the motor gets hot that carbon build up heats up and causes that diseling, could also be leaky injectors in comination. i would start with a top engine cleaning not that cheap crap at kragen either have a shop do it so that the concentrate will be alot higher.


and i would put a fuel pressure gauge on prime it and see how long it holds pressure and the rate it drops

 

Yeah, have a fuel system flush done on your car. I think we charge just over $100 for that.

 

I was thinking the exact same thing.

I used to have an old "mileage unknown" GM Goodwrench motor that had probably over 300,000 miles on it.

If you put 87 in that motor it would ping and diesel for like 10 seconds

With 91 it ran great!

Came to the conclusion that it just had so much carbon buildup inside it, that it was just picky in its old age.

I sold that engine too and it is still running today I bet

My rebuilt "Free-oh-5" a.k.a. "Wee-oh-five" will take 87 with some minor pings.

Just spend the extra $1 you cheap ****

 

is there any truth to the Dribble some water down the carb and it will "Steam" clean the combustion chamber? or is it just a bunch of "hot gass" comming from the older(ie before computer controled crap) group? because if it does do something, i might just try it, after of course i hit the Jyard to get me a "new" power break booster.

 

haha we charge 60 for that at my shop

 

Exactly where would i place the gage at on a carb car?

 

what all does it involve? and yeah we're more pricey than most shops.. but we won't fill your radiator with oil

 

yeah there is some truth to that but I wounldn't try it cause if you get to much water thats bad news, I'd just get some top engine clean it will work better than water

 

alright thanks, will do after i get this car, Safe to drive again, Just got back from the jyard, and got some interior trim and a few exterior trim pieces as well (my rear Berlinetta sticker, just need to finshesh repainting it, and i need some glue for it) got me a power break booster, so hopefully its a working one gonna put it in after it cools down a bit this eveing,