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1986 2.5 ignition timing by newfiejeff
Started on: 07-23-2014 08:50 AM
Replies: 12 (304 views)
Last post by: newfiejeff on 07-27-2014 03:53 PM
newfiejeff
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Report this Post07-23-2014 08:50 AM Click Here to See the Profile for newfiejeffClick Here to Email newfiejeffSend a Private Message to newfiejeffEdit/Delete MessageReply w/QuoteDirect Link to This Post
1986 2m4
Hi all, got a question. I know my car pings when it has a strain on it in 5th gear traveling around 45 mphs and when it is put in 4th it gets better, but it is still slightly there. So I assume that the timing will need to be adjusted. The question is what else could cause that besides timing if any? I am at work now and not sure if I will get a chance to do it tonight or not.
Any comments welcome.
Also, is it worth using the timing light for, can't I just adjust it a hair and do a trial and run?

Jeff
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84fiero123
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Report this Post07-23-2014 09:37 AM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by newfiejeff:

1986 2m4
Hi all, got a question. I know my car pings when it has a strain on it in 5th gear traveling around 45 mphs and when it is put in 4th it gets better, but it is still slightly there. So I assume that the timing will need to be adjusted. The question is what else could cause that besides timing if any? I am at work now and not sure if I will get a chance to do it tonight or not.
Any comments welcome.
Also, is it worth using the timing light for, can't I just adjust it a hair and do a trial and run?

Jeff


First I think you are shifting into 5th gear to early, not sure but 5th gear is for cruising not accelerating well not really for accelerating at that speed anyway. Sure you can do it Old School and just loosen up the hold down bolt and turn it a hair one way, to be honest I forget what way is to advance and what way is to retard timing as it has been so long. But I regress. loosen the hold down bolt a little and mark your starting point of the position of your distributer. Now turn it a hair in one direction and tighten the bolt back down and drive the car and see if it helps or makes it worse. If it makes it worse start over and go the other way a hair past your starting point and lock it and drive it again. Do not go to far ether way, but once you get it to acting better try going just a little more a few times until you make it worse, you will eventually make it worse no matter what.

If you have a timing light it would make it easier but is not absolutely needed. As I said above but something else I said above is that I think you are trying to shift into 5th gear and accelerate at to slow a speed for 5th gear. Another thing you can try is if you are not using premium fill the tank and see if that helps, it should, a little but is not really needed and an extra expense you don't really need for these as they are made to run on regular.

I hope that helped

Steve

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jaskispyder
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Report this Post07-23-2014 09:39 AM Click Here to See the Profile for jaskispyderSend a Private Message to jaskispyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
You can check the timing, but try a tank of premium gas first

My '87 would ping going up a long hill when running on 87 octane.

As for setting the timing. You need to follow the procedure, which includes jumping A & B in the ALDL harness and then setting the base timing. The computer advances the timing from there. You could perform a search here on the forum to look for timing instructions for a fiero.
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Gall757
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Report this Post07-23-2014 09:52 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
The Duke is designed to run on regular gas, but if the engine has a lot of carbon deposits, it can ping....they call it pre-detonation. Higher octane fuel may fix it, but you can also use some of the more well known gas treatments such as Lucas....to clean up the carbon.
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newfiejeff
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Report this Post07-23-2014 10:01 AM Click Here to See the Profile for newfiejeffClick Here to Email newfiejeffSend a Private Message to newfiejeffEdit/Delete MessageReply w/QuoteDirect Link to This Post
I will put the light on it and if its correct then I will try the fuel or an additive before moving the distributor.
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jaskispyder
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Report this Post07-23-2014 10:09 AM Click Here to See the Profile for jaskispyderSend a Private Message to jaskispyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
Don't forget to jump A&B, otherwise, you will see the computer controlling the timing and it will look like it is off.
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phonedawgz
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Report this Post07-23-2014 11:56 AM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by newfiejeff:

can't I just adjust it a hair and do a trial and run?

Jeff


Yes - Clockwise retards it (what you want)
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Patrick
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Report this Post07-23-2014 03:58 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by newfiejeff:

I know my car pings when it has a strain on it...


Is your EGR valve connected and functional?

Many variables will affect the amount of advance the ignition timing can have before pinging occurs. I run my '84 duke at 12° BTDC with regular gas and it's fine... no pinging with the pedal to the metal while going up a hill in 4th.

 
quote
Originally posted by newfiejeff:

Also, is it worth using the timing light for, can't I just adjust it a hair and do a trial and run?


I time my engines "by ear", but you need to be careful or engine damage could occur. I'll then use a timing light to (out of curiosity more than anything else) to see where I ended up.

EDIT: I should also add that maximum ignition timing for best power/mileage does not necessarily produce the lowest emission levels. Therefore, to pass smog tests, the ignition advance often needs to be backed off (and/or simply set to factory specs).

[This message has been edited by Patrick (edited 07-23-2014).]

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newfiejeff
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Report this Post07-23-2014 07:00 PM Click Here to See the Profile for newfiejeffClick Here to Email newfiejeffSend a Private Message to newfiejeffEdit/Delete MessageReply w/QuoteDirect Link to This Post
FYI.

There is no EGR valve on the car and the vacuum line is plugged.
Does that make a difference?
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Patrick
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Report this Post07-23-2014 07:28 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by newfiejeff:

There is no EGR valve on the car and the vacuum line is plugged.
Does that make a difference?


Well..... ya!
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newfiejeff
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Report this Post07-24-2014 04:28 AM Click Here to See the Profile for newfiejeffClick Here to Email newfiejeffSend a Private Message to newfiejeffEdit/Delete MessageReply w/QuoteDirect Link to This Post
Lol.
What I mean is that going to make her ping regardless or will it be a totally different number than most cars?
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Csjag
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Report this Post07-24-2014 08:47 AM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
On my 85 duke I removed the throttle body and found it to be pretty carboned up from the egr valve. I thoroughly cleaned it and also removed the intake baffle and blocked off the egr. I also put a rebuild kit in the fuel pressure regulator and turned up the fuel pressure a little by taking off the screw cover and turning up the tension a little. I then advanced the timing to about 13 degrees. The car now has much better throttle response and accelerates quicker with no pinging on regular gas.
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Report this Post07-27-2014 03:53 PM Click Here to See the Profile for newfiejeffClick Here to Email newfiejeffSend a Private Message to newfiejeffEdit/Delete MessageReply w/QuoteDirect Link to This Post
Adjusted timing both ways, I made it worse and then adjusted the opposite way and it is a shim better. I will leave it at that and see what I can do probably about carbon, etc.
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