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Discussion Starter · #1 ·
Ok first. I am in no way great with this motor but got it in and running but it idles high right around 1200-1300 and has no power when I drive it I know that. I need to readjust the valves because I followed the Clinton's I got for it and the spec in it is different from the hood sticker but would like to get the idle right before I pull the valve cover I pulled the air pump off and have double checked all of the vacuum lines but still no change the truck is a 1990 isuzu pickup does anybody have a good vacuum line map or write on it with out the air pump and air management valve. I live in a state without emissions so I want to delete all of that crap and what I have read on here you can get rid of everything on it correct me if I am wrong I appreciate any info on it

Thank you
Derek
 

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Discussion Starter · #4 ·
Thanks for the diagram And as for timing cam to crank is good or at least it was when I put it together I will double check it in the morning and as for ignition timing I am waiting on a timing light going to check that in the am to and I just found the idle set screw correct me if I am wrong but to adjust the idle is just a matter of adjusting the screw
 

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Yes , adjusting the screw will work.Also check and make sure that there is no gunk on your throttle cable.Sometimes the heat of the engine will melt that boot and cause the cable to stick.You can also make sure your cap is seated right or the distributor itself is maybe not a gear off? Just a thought
 

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Discussion Starter · #6 ·
Thanks for the info I believe I've got the timing right now and after readjusting the valves she runs a lot better but still idles high I have triple checked all of my vaccuum lines and they are all right do you know of a way to test the IAC? I believe it's not working as its support to any info on it will help thanks
 

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You have a Chiltons manual? Its on page 4-13, it talks about the testing procedure there.You will need a voltmeter. While you have the voltmeter under the hood , its always good practice to test all your other sensors as well
 

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Slamming1314 said:
I just found the idle set screw
Where did you find the screw ?

Under the throttle linkage, or behind the TPS ?
 

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Discussion Starter · #9 ·
Jjhayden yea I have a Clinton's manual I looked in there I will check it again I prolly over looked it thanks for the info. Selador the set screw under the throttle linkage I didn't know there was One under the tps is there? Thanks again
 

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Slamming1314 said:
Jjhayden yea I have a Clinton's manual I looked in there I will check it again I prolly over looked it thanks for the info. Selador the set screw under the throttle linkage I didn't know there was One under the tps is there? Thanks again
That's what I suspected.

I hope you haven't messed with that screw yet. If not, then be happy you didn't, and leave it alone.

If you have, then you need to get it back to as perfectly the same as it was before, as possible.

Look on the throttle body, on the side opposite the linkage.

See the little black box ? That is the Throttle Position Sensor.

Behind that box, between the box, and the common chamber, you'll find a little hole with a screw in it. That is the idle set screw.

Here is the idle set screw.


This is not the idle set screw, and should not be messed with.
 

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Thats exactly what i was looking for selador,the pic of set screw near accel.cable,could you tell me how many threads are showing above, foemer owner thought it was idle,and then i thought it was,so i would like to adjust to as close as i can. thanks looks like two and half,to three showing!
 

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rattletrap89trprII said:
Thats exactly what i was looking for selador,the pic of set screw near accel.cable,could you tell me how many threads are showing above, foemer owner thought it was idle,and then i thought it was,so i would like to adjust to as close as i can. thanks looks like two and half,to three showing!
My set screw may be very different from yours.

I beleive that if you do some searching around here, you'll find threads that will guide you through setting that for your own application.

I think you'll have to have a wire type gauge, to measure a particular amount of opening on the throttle plates You'll adjust the screw to get that amount of opening, then tighten down the nut to hold it there.
 

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oh i see each motor could be a little different,do you know correct name of this set screw,besides screw thingy by acc.cable....i know i sound dumb but i can do the work with pics,or over the shoulder guide,just don't know the lingo.....But I will !!!! lol
 

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rattletrap89trprII said:
oh i see each motor could be a little different,do you know correct name of this set screw,besides screw thingy by acc.cable....i know i sound dumb but i can do the work with pics,or over the shoulder guide,just don't know the lingo.....But I will !!!! lol
I'm not sure what it's called.

Try throttle plate adjust screw.
 
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