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Thunderbolt IV distributor install ???

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duckhunter185

Contributing Member
Going to install thunderbolt IV distributor on my 94 4.3 lx and it has the ignition modual on it with the 2 wires coming out of it white/green and white/red i think... Figured the modual needed to be facing back since it hits the top of the intake when facing the front of the engine. The #1 spot on the cap is now facing back. What to do? Does the rotor not have to be pointed at #1 when timing it? Thanks!
 
You MUST DO THIS!!!!!!!!!!!


rotate engine while watching NUMBER 1 intake rocker arm and when the rocker arm is lifted by the push rod and then goes back down, line up the timing mark on TDC or 0 degrees on the timing chain cover to the harmonic balancer. it may take a bit of time and if missed you must go around twice on the harmonic balancer to get top dead center again on number 1 intake stroke.

Once there install the distributor as you decribed with the module facing back and as you are putting it into motor try to get the rotor to point at NUMBER ONE position on the distributor cap!!!!!

The dist housing may not seat all the way for now but once the oil pump lines up it will so only snug the dist housing clamp and DO NOT tighten until fully seated and timing set. Because you do NOT have a knock sensor and an additional module then no jumping of wires needed to find base timing. Just set it as any normal old style timing proceedure.
 
Yes, ditto Kghost! (I just now saw his post)

duckhunter185 said:
Figured the modual needed to be facing back since it hits the top of the intake when facing the front of the engine. The #1 spot on the cap is now facing back. What to do? Does the rotor not have to be pointed at #1 when timing it?
Click to expand...
Typically, and via an unwritten rule, we aim the rotor towards the physical location of #1 cylinder, but this "rule" can be bent!
The rotor can actually point in any direction that you want it to, as long as the cap is wired correctly as per each cylinder.
However, if the distributor cap is marked for each cylinder, you should index the distributor housing to accommodate this.

Just make certain that #1 cylinder is up on TDC C/S, and not at the end of the E/S.


.
 
Last edited:
RicardoMarine said:
Typically, and via an unwritten rule, we aim the rotor towards the physical location of #1 cylinder, but this "rule" can be bent!
The rotor can actually point in any direction that you want it to, as long as the cap is wired correctly as per each cylinder.
However, if the distributor cap is marked for each cylinder, you should index the distributor housing to accommodate this.

Just make certain that #1 cylinder is up on TDC C/S, and not at the end of the E/S.


.
Click to expand...


Unfortunatly with mercs design typically NUMBER 1 cap location is pointing to 9:00 looking at it from the front of engine..........at least on the ones with the distributor mounted timing controll modules and for a fact with the ones with both the timing and knock control module piggy backed to the distributor housing.......
 
I too always thought you needed the rotor pointed at the #1 cylinder. That's why I was confused. My cap is numbered for each cylinder. Is it still ok to have the module facing back as long as #1 is TDC and the rotor is facing the #1 spot on the cap. Which is not facing #1 cylinder. Thanks you guys are great!
 
Yep, the cap, rotor, distributor, pistons, camshaft, crankshaft and even the spark plugs won't know the difference, unless you tell them! :rolleyes:
Even then, I don't think they'll care! ;)
 
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