Distributor Transplant went well, but the timing?
Thread Starter
Member
Joined: Jan 2002
Posts: 482
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From: Broomall, PA
Car: 1992 Chevrolet Camaro RS; 1986 Oldsmobile Cutlass Ciera Brougham
Engine: LH0 3.1 Liter V6; YBN 2.8 Liter V6
Transmission: TH-700-R4; TH-440
Distributor Transplant went well, but the timing?
Hey guys,
I put my new distributor in (brand new pickup and ICM with it, as well as a cap and rotor), and I fired it up, went good, then I noticed a cylinder would miss occasionally. About once every 2 seconds. THen I went on the road for a drive to fill up at the local Texa-hoe, and I put it back in gear and it died on me, and would die at lights if i didnt put it in nuetral. I am guessing that the timing is way off and that the cylinders are missing a little more when driving, but I am taking it a half mile up the road for a timing job, cause I dont have a light here, should I rotate the dissy just a little bit before I do or will the occasional missing screw up anything in my engine? let me know thanks.
I put my new distributor in (brand new pickup and ICM with it, as well as a cap and rotor), and I fired it up, went good, then I noticed a cylinder would miss occasionally. About once every 2 seconds. THen I went on the road for a drive to fill up at the local Texa-hoe, and I put it back in gear and it died on me, and would die at lights if i didnt put it in nuetral. I am guessing that the timing is way off and that the cylinders are missing a little more when driving, but I am taking it a half mile up the road for a timing job, cause I dont have a light here, should I rotate the dissy just a little bit before I do or will the occasional missing screw up anything in my engine? let me know thanks.
Thread Starter
Member
Joined: Jan 2002
Posts: 482
Likes: 0
From: Broomall, PA
Car: 1992 Chevrolet Camaro RS; 1986 Oldsmobile Cutlass Ciera Brougham
Engine: LH0 3.1 Liter V6; YBN 2.8 Liter V6
Transmission: TH-700-R4; TH-440
by the way when i said rotate i meant back not more forward. WOuld it be a good idea to get it timed the right way even if it seems to be running good after i rotate before taking it up there?
Supreme Member
Joined: Mar 2000
Posts: 13,414
Likes: 6
From: Central NJ, USA
Car: 1986 Firebird
Engine: 2.8 V6
Transmission: 700R4
Talked about this a lonnng time ago; in the midst of an argument where it was thought that the #1 plug wire was always in the same spot on a distributor cap, for every engine. 
Hope that helps. How much are they charging you for the timing? You can grab a light for $30 or so, and you'll use it many times- hopefully once every year, to check your timing, as part of a major tuneup...
Originally posted by TomP
Alright. Here comes an explanation as to "why the #1 plug wire is NEVER in the same spot on a distributor cap".
-----------------------------------------------------
Okay- there's two things that spin as regards ignition timing: The distributor housing and the distributor's rotor. There's one major thing that needs to be addressed for ignition timing: The distributor's rotor must be in the firing position for the #1 cylinder when the #1 cylinder is at top dead center.
Here's why "you can never tell where a #1 plug wire should be on a distributor cap by looking at it's position in the engine bay."
The distributor housing ITSELF, cap and all, can be rotated!!
(Ugh, how do I explain this without pictures...)
Say I have two 2.8l engines, "A" and "B", both of which I've set their #1 piston to TDC of the compression stroke. By saying this about TDC, this means that the only engine part I need to concentrate on is the distributor.
Say I've pulled their distributors. Now, say I hold both of the distributors so the spark module connections face to the firewall.
Say I use white-out to mark the passenger-side-most terminal on engine "A"'s distributor cap to be the "#1 cylinder".
Say I label the driver-side-most terminal on engine "B"'s distributor cap to be the #1 cylinder.
I now drop the "A" distributor into engine "A". I make sure that when the distributor is fully seated, the rotor points to the extreme passenger-side-most terminal on the cap.
I now drop the "B" distributor into engine "B". I make sure that when the distrib is in the motor all the way, the rotor points directly to the driver's side.
Now, I install the distributor caps.
Engine "A"'s distributor's rotor is pointing to the passenger side. It lines up with the #1 cylinder mark I made on the distributor cap, which was the terminal pointing to the passenger side.
Engine "B"'s rotor points to the driver's side, to meet exactly with a distributor terminal.
On both engines ("A" & "B"), I now run the spark plug wires clockwise. I use the mark I made on their caps as a reference for the #1 plug wires, and therefore, ALL of the plug wires. Looking at the top of the distributors, the wires coming from the cap are:
-----------------------------------------------------
"Engine A", rotor pointing: <<----
...2...3...
1....c....4
...5...6
-----------------------------------------------------
"Engine B", rotor pointing: ---->>
...5...6... "Engine B"
4....c....1
...3...2
-----------------------------------------------------
Both engines are now timed, as I first said, so that the distributor's rotor must be in the firing position for the #1 cylinder when the #1 cylinder is at top dead center.
And this is why you can not determine where the #1 plug wire should be in relation to anything in the engine bay, other than the #1 cylinder's piston position (TDC).
Does this do it? If I confused anybody, let me know. I could've shown it with two pictures much easier.
Note, of course, that sure, GM may make these cars' distributor's point all the same way. But after previous owners and garage work, the position of the #1 plug wire on the cap compared to parts in the engine bay should never be taken for granted.
Alright. Here comes an explanation as to "why the #1 plug wire is NEVER in the same spot on a distributor cap".
-----------------------------------------------------
Okay- there's two things that spin as regards ignition timing: The distributor housing and the distributor's rotor. There's one major thing that needs to be addressed for ignition timing: The distributor's rotor must be in the firing position for the #1 cylinder when the #1 cylinder is at top dead center.
Here's why "you can never tell where a #1 plug wire should be on a distributor cap by looking at it's position in the engine bay."
The distributor housing ITSELF, cap and all, can be rotated!!
(Ugh, how do I explain this without pictures...)
Say I have two 2.8l engines, "A" and "B", both of which I've set their #1 piston to TDC of the compression stroke. By saying this about TDC, this means that the only engine part I need to concentrate on is the distributor.
Say I've pulled their distributors. Now, say I hold both of the distributors so the spark module connections face to the firewall.
Say I use white-out to mark the passenger-side-most terminal on engine "A"'s distributor cap to be the "#1 cylinder".
Say I label the driver-side-most terminal on engine "B"'s distributor cap to be the #1 cylinder.
I now drop the "A" distributor into engine "A". I make sure that when the distributor is fully seated, the rotor points to the extreme passenger-side-most terminal on the cap.
I now drop the "B" distributor into engine "B". I make sure that when the distrib is in the motor all the way, the rotor points directly to the driver's side.
Now, I install the distributor caps.
Engine "A"'s distributor's rotor is pointing to the passenger side. It lines up with the #1 cylinder mark I made on the distributor cap, which was the terminal pointing to the passenger side.
Engine "B"'s rotor points to the driver's side, to meet exactly with a distributor terminal.
On both engines ("A" & "B"), I now run the spark plug wires clockwise. I use the mark I made on their caps as a reference for the #1 plug wires, and therefore, ALL of the plug wires. Looking at the top of the distributors, the wires coming from the cap are:
-----------------------------------------------------
"Engine A", rotor pointing: <<----
...2...3...
1....c....4
...5...6
-----------------------------------------------------
"Engine B", rotor pointing: ---->>
...5...6... "Engine B"
4....c....1
...3...2
-----------------------------------------------------
Both engines are now timed, as I first said, so that the distributor's rotor must be in the firing position for the #1 cylinder when the #1 cylinder is at top dead center.
And this is why you can not determine where the #1 plug wire should be in relation to anything in the engine bay, other than the #1 cylinder's piston position (TDC).
Does this do it? If I confused anybody, let me know. I could've shown it with two pictures much easier.
Note, of course, that sure, GM may make these cars' distributor's point all the same way. But after previous owners and garage work, the position of the #1 plug wire on the cap compared to parts in the engine bay should never be taken for granted.
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