86 Toy truck std.Every time my engine is warmed up and i take off from 1st gear,it pings some.It never does this any other time.I decided to check the timing and it was at around 0*.If i were to advance it,wouldn't it increase the pinging?I currently get around 33m.p.g.,but,I'm greedy and i want more mpg's!!I run 87 octane
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suggested timing for 22r engine...
- Thread starter daves66nova
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daves66nova
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Ooops.Should have said i stripped all emissions equipment,replaced stock carb with a Holley/Weber carb,header,MSD 6.According to when i last used my wide-band meter,it was running at roughly stoich. ratio.
With both vac lines removed from the distributor it should be 0* at idle. With the vac lines connected it should be about 8* at idle. As you advance the throttle the timing should drop just off idle then advance up to about 28*. If you are not using the vacuum advances then you can't set the timing properly. Vacuum advance is for better mpg, not emissions.
You actually WANT 8-10 at idle, then a decent curve when operating.
Is the pinging at part throttle, full throttle, or both?
Mid RPM ? High?
Is the pinging at part throttle, full throttle, or both?
Mid RPM ? High?
daves66nova
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It only pings a little when i take off from 1st gear and only when fully warmed up.I also noticed that if i have it in 1st at the lowest rpm rolling and i accelerate a little hard it stumbles pretty good.Not enough pump shot? It has 3 settings for this and it's already at the biggest shot.Also,the dist housing is already at the most advanced position.It only moves so much.How can i reposition the shaft so that i can have more advance?
Originally Posted By: daves66nova
Also,the dist housing is already at the most advanced position.It only moves so much.How can i reposition the shaft so that i can have more advance?
Sounds a little mixed up?
You have pinging, yet you also want more advance?
Also,the dist housing is already at the most advanced position.It only moves so much.How can i reposition the shaft so that i can have more advance?
Sounds a little mixed up?
You have pinging, yet you also want more advance?
Your distributor is 1 tooth off or your timing chain is stretched.
A stumble can be lean mixture or retarded timing. We don't know what advance curve you have right now.
[Stuff is disconnected.]
There is a different curve for full throttle and part throttle.
Can you see what the max advance is? Somewhere around 32 would be good. You probably have less, but your intermediate is off if you are pinging. [or carbon deposits ].
BTW, if you HAVE to, you can open up the slots on the distributor to more it more. Don't do this unless you have a very good grasp on what you intend to do.
[Stuff is disconnected.]
There is a different curve for full throttle and part throttle.
Can you see what the max advance is? Somewhere around 32 would be good. You probably have less, but your intermediate is off if you are pinging. [or carbon deposits ].
BTW, if you HAVE to, you can open up the slots on the distributor to more it more. Don't do this unless you have a very good grasp on what you intend to do.
Originally Posted By: mechtech2
BTW, if you HAVE to, you can open up the slots on the distributor to more it more. Don't do this unless you have a very good grasp on what you intend to do.
You should not have to do this, the slot ranges more than one gear tooth on the distributor drive.
And Yes, if it's at it's maximum you very proberbly have a stretched timing chain.
Where do you draw vacuum from on the Weber carb?
BTW, if you HAVE to, you can open up the slots on the distributor to more it more. Don't do this unless you have a very good grasp on what you intend to do.
You should not have to do this, the slot ranges more than one gear tooth on the distributor drive.
And Yes, if it's at it's maximum you very proberbly have a stretched timing chain.
Where do you draw vacuum from on the Weber carb?
Last edited:
Originally Posted By: daves66nova
I currently get around 33m.p.g.,but,I'm greedy and i want more mpg's!!I run 87 octane
Wow, I have this 86 Toyota truck in 4X4 with 100,000 miles on it and I get 26 mpg with the 20% larger imperial gallon of gas. Take the 33 mpg and run, with a Canadian Imperial Gallon measurement that would be 39 mpg up here. The U.S. gallon is 20% smaller than Imperial gallon for interest sake.
I believe the time listed under my hood is 6 or 8 degree before tdc.
Dave66Nova, what and how did you tear off on emmisions, please describe a bit as I am not all that mechanically literate, I want to increase my mileage as you obviously did, emmissions mean nothing up here, all not regulated and if I can increase mileage by 15 mpg then I have to believe my truck would be better on emmissions anyway. Is the spark plug gap 40 or 35?
Cyprs
I currently get around 33m.p.g.,but,I'm greedy and i want more mpg's!!I run 87 octane
Wow, I have this 86 Toyota truck in 4X4 with 100,000 miles on it and I get 26 mpg with the 20% larger imperial gallon of gas. Take the 33 mpg and run, with a Canadian Imperial Gallon measurement that would be 39 mpg up here. The U.S. gallon is 20% smaller than Imperial gallon for interest sake.
I believe the time listed under my hood is 6 or 8 degree before tdc.
Dave66Nova, what and how did you tear off on emmisions, please describe a bit as I am not all that mechanically literate, I want to increase my mileage as you obviously did, emmissions mean nothing up here, all not regulated and if I can increase mileage by 15 mpg then I have to believe my truck would be better on emmissions anyway. Is the spark plug gap 40 or 35?
Cyprs
If your ignition is in great shape, a slightly wider gap is best for gas mileage. It has a bigger/hotter spark for lean cruising conditions. Normally , we can open them up .005" with no problems.
Some go more.
Some go more.
I wander about my time chain too. It is too bad the 86 Toyota does not have the adjustible timing chain sprocket as does the B200 (1957cc) Datsun motor have in 1980, years ago we adjusted the stretched timing chain with this sprocket adjustment, the sprocket can actually be adjusted twice as there are two marks on sprocket. One has to be extremely carefull to support the chain or it will fall and the tensioner has to be re-installed, learned that the hard way.
Cyprs
Cyprs
daves66nova
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Originally Posted By: expat
Originally Posted By: daves66nova
Also,the dist housing is already at the most advanced position.It only moves so much.How can i reposition the shaft so that i can have more advance?
Sounds a little mixed up?
You have pinging, yet you also want more advance?
Sorry for the long delay in responding.The accelerator pump screws were a little loose,spilling some gasoline instead of getting squirted into carb.This really helped out the pinging.As for the timing,it was at 0*,so I retarded the dist. housing,then advanced the dist gear 1 tooth. Now I have a lot of room for advance. I have kept it at about 5* for now til I see what gains,if any,are made.
Originally Posted By: daves66nova
Also,the dist housing is already at the most advanced position.It only moves so much.How can i reposition the shaft so that i can have more advance?
Sounds a little mixed up?
You have pinging, yet you also want more advance?
Sorry for the long delay in responding.The accelerator pump screws were a little loose,spilling some gasoline instead of getting squirted into carb.This really helped out the pinging.As for the timing,it was at 0*,so I retarded the dist. housing,then advanced the dist gear 1 tooth. Now I have a lot of room for advance. I have kept it at about 5* for now til I see what gains,if any,are made.
daves66nova
Thread starter
Originally Posted By: expat
Originally Posted By: mechtech2
BTW, if you HAVE to, you can open up the slots on the distributor to more it more. Don't do this unless you have a very good grasp on what you intend to do.
And Yes, if it's at it's maximum you very proberbly have a stretched timing chain.
Where do you draw vacuum from on the Weber carb?
The chain was replaced a few months ago.The Holley/weber carb has a ported vac. source.
Originally Posted By: mechtech2
BTW, if you HAVE to, you can open up the slots on the distributor to more it more. Don't do this unless you have a very good grasp on what you intend to do.
And Yes, if it's at it's maximum you very proberbly have a stretched timing chain.
Where do you draw vacuum from on the Weber carb?
The chain was replaced a few months ago.The Holley/weber carb has a ported vac. source.
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