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Does anyone have any idea why my 88 s-10 2.8 liter is at tdc but my distrubutor rotor is pointing towards the number 2 cylinder and not 1. Truck will crank but won’t start
Can you give a bit of history on this? A bit of a run down on what has happened. Was the truck running and just stop? On 2.8 the #1 is on passenger side. What has been done to try to fix and so on? If the distributor is loose it could have rotated to cause the problem. Lots of possibilities, information helps.
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1984 S15 2.8 5 sp
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Does anyone have any idea why my 88 s-10 2.8 liter is at tdc but my distrubutor rotor is pointing towards the number 2 cylinder and not 1. Truck will crank but won’t start
Turn the distributor (without removing it) until #1 on the cap points to the rotor, when at TDC compression stroke on #1; if you’re TDC on the exhaust you’ll be TDC compression on #4.


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Discussion Starter · #7 ·
Can you give a bit of history on this? A bit of a run down on what has happened. Was the truck running and just stop? On 2.8 the #1 is on passenger side. What has been done to try to fix and so on? If the distributor is loose it could have rotated to cause the problem. Lots of possibilities, information helps.
View attachment 371104
It was running before I put new spark plugs, wires cap and rotor then I put everything back on and it didn’t want to start, it’ll crank over but no start
 

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You sure you got all the plug wires in the right spot and connected to the correct cylinder? I've done that before, when "stabbing" a distributor on my 3.4 swap, and still got it 180 deg out. I cheated and just switched wires instead of pulling the distributor. It's easy enough to get it mixed up, even if you're aware of the issue.

Another thing that can cause your suspected TDC to be off is a slipped bond on the harmonic balancer. As noted in prior posts, you'll have TDC on #1 and #4 cyl's at the same time, but only one of those cyls will be on its compression stroke.

You've got to pull #1 spark plug and stick your finger over the spark plug hole so you can feel compression as #1 piston is rising to TDC with both valves closed. Make a makeshift pointer out of coat hanger wire or something else suitable, once you know you're on the compression stroke, use the tool (in spark plug hole against the piston) to get an indication of the piston at TDC.

Once you're absolutely sure you're at TDC compression stroke on #1 cyl, then you can check your harmonic balancer and see if its timing mark aligns with TDC on the timing scale. If it does, you're golden; if not, you need a new balancer.

You can also check to make sure the plug wire you've designated as #1, is in the distributor in the correct spot, to where the rotor is pointing at that contact.

Once you've got #1 cyl established on the cap, the rest follow; 1-2-3-4-5-6 clockwise around the cap.

If the distributor is installed correctly, #1 cyl on the cap will be in approx 7 o'clock position as you're standing in front of the rig, looking at the engine.

But if #1 is somewhere else, it doesn't really matter as far as the engine's running, as long as all the other plug wires follow correctly. However, having the rotor point to #1 on the cap at #1 cyl TDC (compression stroke) is critical. Ain't gonna run unless that's correct.

Hope that helps, let us know what you find............ed
 

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Discussion Starter · #9 ·
You sure you got all the plug wires in the right spot and connected to the correct cylinder? I've done that before, when "stabbing" a distributor on my 3.4 swap, and still got it 180 deg out. I cheated and just switched wires instead of pulling the distributor. It's easy enough to get it mixed up, even if you're aware of the issue.

Another thing that can cause your suspected TDC to be off is a slipped bond on the harmonic balancer. As noted in prior posts, you'll have TDC on #1 and #4 cyl's at the same time, but only one of those cyls will be on its compression stroke.

You've got to pull #1 spark plug and stick your finger over the spark plug hole so you can feel compression as #1 piston is rising to TDC with both valves closed. Make a makeshift pointer out of coat hanger wire or something else suitable, once you know you're on the compression stroke, use the tool (in spark plug hole against the piston) to get an indication of the piston at TDC.

Once you're absolutely sure you're at TDC compression stroke on #1 cyl, then you can check your harmonic balancer and see if its timing mark aligns with TDC on the timing scale. If it does, you're golden; if not, you need a new balancer.

You can also check to make sure the plug wire you've designated as #1, is in the distributor in the correct spot, to where the rotor is pointing at that contact.

Once you've got #1 cyl established on the cap, the rest follow; 1-2-3-4-5-6 clockwise around the cap.

If the distributor is installed correctly, #1 cyl on the cap will be in approx 7 o'clock position as you're standing in front of the rig, looking at the engine.

But if #1 is somewhere else, it doesn't really matter as far as the engine's running, as long as all the other plug wires follow correctly. However, having the rotor point to #1 on the cap at #1 cyl TDC (compression stroke) is critical. Ain't gonna run unless that's correct.

Hope that helps, let us know what you find............ed
Appreciate the feed back!! I’ve tried all of that and have confirmed tdc and the rotor pointing at the #1 cylinder with the 1 on the cap being pointed at the rotor and wires clockwise and I still have got nothing
 

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Have you tried starting fluid to confirm it's not a fueling issue? Have you checked to be sure both electrical connectors from the distributor are connected tight? Any of those wires damaged? Are you getting spark to the center of the cap from the coil?
 

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If it was running before you did a tune up, then the problem lies within what you did during that tune up.

The most likely issue is that you have the spark plugs on the wrong towers of the distributor cap. A secondary possibility is that the distributor has been stabbed a tooth off and so the wires were just moved around the cap to compensate.

Do not look deeper than where the problem lies, you have a high potential to make it worse. Look at the work you did an figure out where something went wrong.
 
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Discussion Starter · #12 ·
Have you tried starting fluid to confirm it's not a fueling issue? Have you checked to be sure both electrical connectors from the distributor are connected tight? Any of those wires damaged? Are you getting spark to the center of the cap from the coil?
I had tried starting fluid and I am getting spark to the center of the cap, the wires are not damaged
 

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Not trying to be funny. You check out the rotor? Could be defective if it was replaced. If you are getting spark at the center of the cap / coil wire you should be getting it at a plug. Could also be the tip that contacts the rotor inside the cap.
 

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Discussion Starter · #14 ·
Not trying to be funny. You check out the rotor? Could be defective if it was replaced. If you are getting spark at the center of the cap / coil wire you should be getting it at a plug. Could also be the tip that contacts the rotor inside the cap.
I have not, there is a good chance it is defective, I’ve had people tell me the whole distrubutor may have to be replaced also
 
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