Engine Ping!!!!!!!
 

So here it is...
1986 GMC C1500
Stock 305 4bbl. When I start the truck, I usually let it warm up for a few seconds before I start driving. While the engine is still cold, the engine starts to ping. If I really give er, she pings even more. The only time it stops pinging is when she is warmed up (190 degrees). Then I don't hear anything from her. Has anyone had this problem? Oh yeah, it's not the timing. It's set right.

Thanks,

Joe

Burn a few tanks of good fuel. Shell 'V Power' (I think) comes to mind. She just has a bit of carbon in there. You can read about it at the Shell site.

All fuel isn't even remotely the same. Especially the crap at the corner store.

After that maybe a tank of the good stuff every 10 or so.

Dave

My 86 does the same thing no matter where I set the timing. I am not sure different gas would make any difference. Worth a try

Premium gas for sure will help but that's not the point.

You gotta clean up the inside of the engine. That's where a few tanks of good stuff helps. Shell has 5 times the required cleaners added to their premium gas. All premium gas is NOT the same, -do keep that in mind.

whoa...
91 octane premium at $2.499 in my burb... wow I'm looking at around $100 to fill it up.. i will save my money and spend the usual $60-70... maybe run $20 worth of shell...

Well, after I had bought the truck, I put in a can of cleaner into the crank case. Basicly this stuff is pink deisel fuel. You let it run for 10 minutes and then change the oil. As far as gas goes, I use Sunoco Ultra 94. It's getting expensive here in Ontario Canada but she needs it......

Shell is .89 a liter here in Edmonton, -for the good stuff. Government says in premium gas they must put 'x' amount of cleaners in it. That's what most probably do.

Shell states they put 5 times what is required by law. On their web page they took an old clunker and fed half the motor with their gas and half with everyday corner stuff. Of course one half of the motor got quite clean after a few tank fulls.

Anyway you have years of carbon build up... top of the piston, valves, etc. Unless your motor is shot, stuff put in the crank case isn't going to make it past the rings to get in the cumbustion chamber. Here is a link to the 'v-power' site...

http://www.shell.com/home/Framework?...t_ga_1602.html

hope it works or you could cut and paste it in a tab

Or maybe you could use some of that Seafoam stuff from GM to clean the top end? I've not used it myself but have heard good things about how well it works.

Joe,

I know that you say that your timing is set correctly. Where is it set at? In my 1985 w/305 I can't run it where the factory recommends. I have to retard it slightly. Also Dave is wrong about gasoline. I was an octane technician for an independent test lab for 13 years. All gasolines are blended with the same base components to achieve the minimum octane rating. And the gasoline that you buy at Shell for example might be from the same company that blended the gasoline for the Sunoco station up the road. The detergents in the fuel have no bearing on the actual octane value of the fuel and detergents in the gasoline really are predominantly there to help keep fuel injection systems clean, not really relevant for an old carbed vehicle. There is a difference however in the fuel we use today and the fuel that was produced when our trucks were built. I find that midgrade fuel today is closer to what 87 was in the eighties as far as performance goes but is still a completely different use of components.

You might want to try retarding your timing slighlty and use midgrade octane gasoline. On my truck the factory label states 4 deg., I run mine at 2 deg. on midgrade and have gotten rid of the pinging. I started off by retarding it to 0 deg. to see if it helped and then advanced it from there until I found my sweet spot, which for me is 2 degrees. At 0 deg. I can run 87 octane with no ping, but I prefer 2 with 89.

Hope this helps some and let us know if it works for you.
Darryl

is it stock? if its stock, you shouldnt have any problems running it on 87. if you are, your engine needs to be cleaned and tuned properly.

could be a carb problem, my carb doesn't do right until it's warmed up and it makes a noise until then

The cleaner that GM sells works great . I think it is called Top Engine Cleaner . It cleaned the carbon buildup out of a 1984 3/4 ton with a 454 that I had . That truck sounded like it had a rod knocking . It took two shots of the engine cleaner . I think some folks use a mixture of water and transmission fluid to accomplish the same thing . They just pour a little at a time down the carb with it running at about 2000 rpm . It smokes like crazy but it works . I like the GM cleaner better . Frank

[QUOTE=Drivin' Miss Daisy]Joe,
Also Dave is wrong about gasoline. I was an octane technician for an independent test lab for 13 years. All gasolines are blended with the same base components to achieve the minimum octane rating.

Of course I'm right. Just an electrician tho. I gave a link in a previous message to the Shell test. Pic of valves. Click for a bigger pic. Tells a thousand words -you don't even have to read the stuff.

I never mentioned octane rating. I mentioned premium or v-power because that is the grade Shell put the great amount of cleaners in.

I of course speak from experience... a much better teacher. Same problem, ran a few tanks of mention gas, problem gone. Now run a tank of the gas every once in awhile to keep the carbon out as best as one can without pulling the engine.

I've heard the 'top engine cleaner' (mentioned by another poster) also works and I've heard Exxon has a good fuel but I don't think they are in Canada, -at least where I am and the original poster is in Canada.

Up in Canada we can also vist a local Husky / Mohawk station and burn their premium fuel as it has ethanol in it which is a great cleaner.

So... get the carbon out.

Dave

Dave,
With all due respect. "I of course speak from experience... a much better teacher ". You are correct about experience. I"m just a Chemist, but I learned that if you touch a hot electrical line that it will shock you and then I got advice from an electrician on how to do what I needed done. When I listened I learned. There is something called saturation when components such as detergents are blended into a gasoline. Since I was involved in many of the tests that the website mentions I speak from experience. Just because a company claims to use more detergent does not mean that the detergent works any better at a level 5 times the required level due to saturation of the detergents most effective cleaning range. Since all octane testing is done on engines developed for the information derived, I have done literally hundreds of routine rebuilds and overhauls and no one "finished gasoline" (gasoline ready for consumer use) produced more or less carbon within the engine. And it was routine in the lab in which I worked to look at the intake and exhaust valves on a daily basis to check for excessive carbon buildup that would cause incorrect readings to be obtained and reported. Therefore, The vast majority of gasolines are pretty much the same and if they use more detergent it doesn't necessarily mean that it works any better. It just costs a little more and easily increases the number of barrels of gasoline they have in their tanks to ship across North America.

The GM top engine cleaner is a great tool. We used it in our lab to clean our octane test engines and it really works well and I have used it on several of my cars in the past.
Later

Ok... right now my truck is set at6 degrees.....could be the problem. I used GM CLean when I got the truck. I need to go and get the last e-test done on it this week. So, I went out today and filled up with MID GRADE. Thanks Daryl for your imput. I will try to change the timing down and see what happens.
82C10...I am ruling out the carb on this one. The carb is tuned and it doesn't make the truck ping...I'll work on it and let you guys know.

Joe

Yes the engine is still stock.....for now. I have to adjust my timing I think.

Hey Joe,
Darryl here(changed user name). Hope the timing change works out for you. I know it made a world of difference in the way my truck runs. Keep us posted and good luck!

I ran a tank of 93 a few months ago, and it made an incredible difference. I could tell it cleaned it out. (I normally run the midgrade) My neighbor up the street has an 84 Sierra Classic with a 350 outta a Nova SS (i helped him put it in :metal: ) and he talked about buying some high-octane (like 110?) racing fuel to run through his truck. He never did, but it was a nice thought.

Y'all can throw facts left and right to see who can quote more articles in here, but the basic idea is that running a tank of "The Good Stuff", 93 octance, w/e the hell your local place calls it, is gonna clean out your motor a lil bit assuming you run a lower octane normally. The Citgo 3 houses down from me has crappy-ass gas, so i get my gas (for cheaper) at Super-1 grocerystore, which has a gas station in the parking lot. And ya know what? That gas (wherever they get it from) is much better than Citgo's. Its pure luck-of-the-store and who THEY get it from on how good the gas is, NOT the company. I've gotten gas from 2 different Chevrons on back to back tanks and gotten ****ty gas from one and good from the other.

Runnin' the good stuff once in a while is good. Nuff said ;)

If someone is looking to clean the inside of their motor of deposits wouldn't the quickest route be to use a service like Motorvac. It's not a cure all but it apparently does show marked improvements in performance.

My $0.02 on high octane fuel is that if you need the higher octane to prevent detonation then use it, if your engine doesn't require it then it does nothing for you except cost you more.

:drama: No "articles" quoted from my side Cliff. All of my information (formerly drivin' miss daisy) comes from working in a laboratory that tested fuels for all of the refiners around the country. I state only facts from experience, not what one company claims in an article. Sure there are some gas stations that cannot be trusted when it comes to the gasoline that they are selling. The vast majority however are selling what they claim. In addition, I never said that its not good to run the good stuff occasionaly. What I said is that even though they claim to put 5 times more cleaners in a fuel it does not necessarily mean that it cleans the engine any better than the good stuff with only the minimum federal standards of detergents. It is called the law of diminishing returns. More is not always better. Nuff said. :rolleyes:

HAHA Law of Deminishing Returns..... you got that right bud :metal:
Nah I see where y'all are both comin' from. It just seemed y'all are arguing the same point back at each other and it was kinda :crazy: But i'm no genious obviously ;)

For me, with a tired 305 with more miles than I honestly know (the speedo ain't work for a few years) and my dad drivin' it for a lving, running 2 octane higher ain't exactly worth finding a Shell Station. A tank of Super Unleaded plus some octane booster once every now and then is fine enough for me.

And wow, a lab about gasoline... haha i hope it wasn't you, a ford guy, and a dodge guy. Bet that water cooler would get interesting :lol:
:flag:

:banghead:
Cliff,
I think you might be due for a trip out of Pineville :uhmk: . Might do ya a little good. Keep ya from goin' :crazy:. Just hope it ain't to late :ele:

Later :alky:

:haha:

So the original reply (from me) never quoted octane. Never. Miss daisy or yellow silverado works in a lab but that means nothing. Like I say running a couple of tanks of Shell V-Power will clean out the engine (combustion chamber). This will get rid of the carbon and the ping when using a cheaper gas.

Go to the shell site I previously mentioned and you will see there is no rocket science stuff there. Just a piece of crap engine that was feed Shell v-power fuel to half the motor and regular corner type stuff to the other half.

The government (looking after you here) requires cleaning agents be inserted into the fuel. Probably a reason here. Shell goes it one better and backs it up with a real world test.

Go for it... I just did a 'pinging' hill today to test it out. No ping anymore.

Not sure on an '86 but methinks my computer sets the timing on my '87.

i am curious how MissDaisy's tests refer to TBI versus pure carb and pure injection... i have been having some hesitation and wondering if my burb either has extra buildup or timing or maybe just bad/watered down gas (Local Citgo station)

Screwball,
With the advent of newer technology, ie fuel injection, comes changes in the way fuels are blended and components used. Also federal emissions standards are constantly changing, which puts more pressure on the refiners to research and develop cleaner burning fuels. Each grade of gasoline has to meet a specific set of standards including octane value, vapor pressure (in winter, more vapor pressure aiding in starting and combustion, in summer, lower vapor pressure because the heat naturally helps vaporize the gasoline and build up more pressure), and distillation (which is the determination of the temperature range at which the fuel burns and evaporates and determines the residual amount of unburned fuel that remains after being burned and even the acidity of the residue can be determined). There is a huge battery of tests that gasoline must go through before being presented to the end consumer. In addition there are different specifications for certain regions of the U.S.A and Canada.

Today, since cars and trucks are all being manufactured with fuel injection, gasolines are being produced based on the performance of todays vehicles. Computers that tell the vehicle when to fire how much fuel to burn and exactly where the timing should be have changed the performance of gasoline. Yes, 87 octane is 87 octane, the difference is in the combustion characteristics and the many additives that are put into todays gasolines. Just like in th late 70's when leaded gasoline was being phased out, people found out that their cars and trucks which were designed for leaded fuel didn't perform as well on unleaded, we are finding that our carbureted vehicles don't perform as well on fuels designed for fuel injected vehicles.

Hope this helps and if you have anymore questions just ask.

BTW Dave M don't be a :ben:. If you can't "honestly" "try" to help and at least "act" like an adult, then "please" don't post to "maliciously" insult me.
Thanks