pinging ???

[jmeti000]

76 280z w the L28.....runs fine except when i hit the gas pedal a little more aggressively. if i gradually press down on it...the engine is fine...but if i stomp on it..i get a pinging noise, and sometimes some dark smoke out the exhaust with a strong fuel odor...any ideas??

[hls30.com]

76 280z w the L28.....runs fine except when i hit the gas pedal a little more aggressively. if i gradually press down on it...the engine is fine...but if i stomp on it..i get a pinging noise, and sometimes some dark smoke out the exhaust with a strong fuel odor...any ideas??

My idea is the car doesn't like it when you do thatROFL !

Seriously-check your timing-and the working of the vacuum advance on the distributor, and your plug wires(they may be breaking down) and immediately after running it hard check your plugs.

Will

[beandip]

If it is pinging as you state . Solve the problem because that is detonation and it could damage the engine. Too advanced timing as Will said , and or too low of a octane fuel can be the cause . If the engine has much carbon build up this also cause pinging because it can glow and cause the fuel mixture to prematurely ignite/detonate . Gary

[carrott]

Get it onto a chassis dyno Asap, the AFR can be examined under load and the timing set properly, no guess work.

[hls30.com]

Get it onto a chassis dyno Asap, the AFR can be examined under load and the timing set properly, no guess work.

While a properly used Dyno can diagnose an engine very precisely, unless there is one close by, in less than the time it takes to drive over and back, you would be done-and your wallet would be grateful-but there is somethig to be said for throwing money at a problem-and here it is-if you go that route with an daily driven old car, you will have to keep doing it because you won't learn how to do anything else-in which case you would be better off throwing money at a car dealer and just buying a new car! Part of the enjoyment of an old car is getting to know what makes it tick, and what it takes to make it stop ticking...

Dyno time-$100/hr or $70 for each run not counting the cost of the repairs(not included in dyno time) and round trip drive time and GAS!

Timing gun $20ish wire brush $1, Carb cleaner $2 Spark plug wrench $4-totalling less than $30 and a trip to the parts store(usually much closer than a Chassis Dyno IE: There is a Napa, a Discount Auto Parts, a local parts place, and two Autozones, within two miles of my house. The closest Chassis Dyno is four and a half hours away(according to the phone book)).

Timing test set hook up and use the timing light as per its instructions! Adjust the dizzy as necessary.

Vacuum advance test-With the car off and the cap off the dizzy,

treat the vacuum hose like a straw and watch for movenent in the dizzy.

Plug wire test Wait until dark(turn off any lights that would shine

on the engine, pop the hood, start the car and watch for sparks! If you

see any the wires are bad(sometimes a good coat of silicone lubricant

wiped all over the jackets works as a temporary fix)

Plug check pull the plugs and check their condition. Clean or replace as necessary. Plug condition is a great troubleshooting tool.

All of this could be done in an hour after work and dinner and you got to spend a little time with your car, and learn how to diagnose and take care of a problem.

Will

[carrott]

Go for it ,but while your enjoying the fun of owning an old car you should set aside enough money for a new set of pistons should you get it wrong , ah yes the joys of owning an old car, not.

[hls30.com]

Go for it ,but while your enjoying the fun of owning an old car you should set aside enough money for a new set of pistons should you get it wrong , ah yes the joys of owning an old car, not.

Tony,

If the car was turbocharged you would be right, however, it appears to be a normally aspirated 1976 l28! in his current situation He can hear and avoid the detonation. Without a high compression ratio (whether due to forced induction or not) the problem can be addressed with adjusted timing, higher octane fuel and driving habits until the issue causing it can be found. The problem is one to be checked into, and dealt with, but unless he never gets his foot out of the go juice, he does not have enough compression to quickly kill the engine. A trip to the dyno will never stop detonation!!! It may give several potential causes of the detionation, but so do the symptoms the car already has. a Dyno run never repaired or temporarily helped anything!!! He will still have to address the problem! He could always take the car into a Z specialist(you know the same one he would have to use after his trip to the Dyno) and have the problem diagnosed and repaired in one sitting. Or he could get out his FSM and do a bit of troubleshooting and repair himself.

Will

[sblake01]

I like your style, Will! But I do get a perverse sort of enjoyment from watching all of the posts on this site encouraging people to throw money at a problem rather than figure it out and fix it.

[hls30.com]

Stephen some people want to know how to fish, and some people just want to know where the grocery store is-they will never get fishing! I am glad those of us with patience, time, and Money? learned how to do the things we post about, No need to post anything if the only answer is "pay someone to handle it."

Tony, I have been in early Zs for 26 years, I don't know everything-don't want to-as Henry Ford said when thwarting an incomptency hearing-"I know where to look."-the forums here are full of answers from people that have been places and had problems with their Zs that I haven't. Some people have better answers than mine-your answer may fit this thread better, the only guy who knows is the one who asked the original question. I would rather give a "don't be afraid to get your hands dirty" answer than a "write a check" answer. Writing a check to answer a problem says to me I can't or I don't want to do this.

I enjoy working on my Z-even when it makes me crazy enough to cuss and throw tools! I wrote this early last year and I still hold it as true:

"To be into cars, at least two of the following criteria must be met on at least a yearly basis. Parts have to be occasionally in your living space(livingroom, dining room, bedroom....) Your hands have to get so dirty it takes a day or two to get them absolutely clean-even with scrubbing. Your tools have to have more wear from your own use than from your admiration."

Notice writing a check, and charging a credit card are notoriously not present! With out meeting the criteria above, a person is not into cars, a person is into being SEEN WITH CARS.

WIll

[sblake01]

Well said! Although I had to get a storage shed since my wife won't tolerate a type A 5 speed sitting on the floor below her shoe rack.

[zbane]

there is somethig to be said for throwing money at a problem-and here it is-if you go that route with an daily driven old car, you will have to keep doing it because you won't learn how to do anything else- Part of the enjoyment of an old car is getting to know what makes it tick, and what it takes to make it stop ticking...

Will, I agree with you, really. As a just beginning tinkerer, however, I do see the need for both options-throw money & get in there.

Even though I have a FSM, basic mechanical knowledge/thirst for more and some of the neccessary tools, I don't have a decent work area (no garage-yes slanted gravel driveway/parking area). Since this is my daily driver, I am also a bit apprehensive about screwing it up.

This is why I have found a shop that allows me into the bay with the mechanics. They show me what is going on, things to watch out for and how to do the task at hand.

Once I see how something is done, and understand why it goes like that (whatever it is), I can generally copy the procedure and/or proceed into deeper waters with more certainty and confidence. For example-with the proper setup, I am fairly certain that I could switch out my tokicos.

Experience counts for quite alot, and I am VERY thankful for all of the shared experience to be found here on this site, but sometimes it seems better to get the Big Picture first hand, in a controlled environment, kind of like school.

I think that if you are unsure about doing it yourself, find someone who will show YOU how to do it, instead of just doing it for you-that way you will at least know a little bit more about your car.

If you give a hungry person a fish, youv'e fed them for one day. If you teach that person how to fish, youv'e fed them for the rest of their life.

"To be into cars, at least two of the following criteria must be met on at least a yearly basis. Parts have to be occasionally in your living space(livingroom, dining room, bedroom....) Your hands have to get so dirty it takes a day or two to get them absolutely clean-even with scrubbing. Your tools have to have more wear from your own use than from your admiration."

And in keeping with your quote (which is great), I met two of the criteria last week when I squirmed under an unjacked gas tank-fun.

David

[hls30.com]

David,

What you have done is prove how smart you are! If you can have someone show or guide you the first time the lesson is easier and the success is insurred. Recognizing that is what brought you here, knowing your limitations and expanding them is what will make you successful-in everyhting!

Taking your car to a shop may be throwing money at a problem, but your answer is also paying for instruction, not just handing off the issue at hand for someone else to deal with.

When I started with Zs, I knew where the key and the gas and the seatbelts went. I didn't know a cressent wrench from a spring compressor. I caught Z-itus and despite the best attempts of my family, several of my friends, and the bitching and moaning of liquid uses of college spending money, I am still infected! As you no doubt are learning there is no cure. It isn't as bad as it seems, just keep a Z close by at all times, and make sure to introduce all significant others to the car early in the relationship-if the car gets jealous, the repair time/bills go up, and the reliability goes down...

Will