Well, I've got the Haynes manual, and here is the diagram it shows for spark plug wires (mine is the 2.5L 4 cylinder according to the sticker on the fan housing - could that sticker be wrong?):



What it doesn't explicitly state is which orientation the distributor is being viewed from. I was under the mistaken impression that all the distributor wires were different lengths, so I didn't take notice when I removed them. The distributor cap only fits on one way. Presumably, the two longest wires are to reach the two farthest park plugs, 1 and 2. The old distributor cap had the two longest wires on the terminals closest to the cab (left side). BUT, if I hook up the wires as the diagram suggests, the two longest wires would be on the TOP, or the RIGHT, depending on how the diagram is to be viewed. So I'm totally stumped.

Is it safe to say that I KNOW the two longest wires must go on the left two terminals (because of the old distributor), and the short two wires on the right two terminals, thus, the left two terminals must be 1 and 2, and the right two terminals must be 3 and 4. That would leave me with only two possible wire configurations, one clockwise and the other counter clockwise. According to the diagram, it's clockwise, but I've already proven the diagram wrong (...or the engine size sticker is wrong?).

Is there another, more certain way other than a sticker to determine the engine size?

In the mean time, I'm going to replace the starter so I don't have to roll the truck down a hill to see if it will start. Thanks!

 

The way it's shown is the way it's set-up, as if you're looking at it from the front just like the way the motor is displayed they show as the fan as being the front, the distributor is displayed the same way. It is possible the shroud the sticker is attached to was replaced and no one made sure that they got the right one, you can use a vin decoder to check against to see what motor you have.

 

I'll try it (again) the way the diagram shows, even though that's not the way the old wires were hooked up. I still have the old distributor cap with the wires hooked to it (I never removed them) and the two longest are on the cap terminals closest to the cab (the two terminals on the 'top' as the diagram shows) meaning those two top terminals MUST be 1 and 2... But that's not what the diagram shows. According to the diagram, the top two terminals are 4 and 1 respectively, going clockwise...

A related question: Is it bad for the wires to be pressed up directly against the engine block? I'm tempted to buy another set of wires, just so I get use four long ones and dispose of the short ones.

I've read that trying the wrong firing order probably won't hurt anything, so I guess I'll just keep trying until it runs fine... The new starter is in, so that should help with the starting. The manual was useless for that too.

On all databases for parts that I've seen (Rock Auto, AutoZone, Advanced Auto, Oriley Auto) the only 4 cylinder engine listed for an 1987 S10 is a 2.5L... That MUST be what I have... I'll try the VIN decoder if I can decipher the VIN from the dash board...

Also, the new muffler is installed, and a cigarette lighter is installed for my GPS. Woot. Don't know if it works yet though.

 

STOP THE FREAKING PRESSES! I just found the following image at http://autorepair.about.com/library/...l-fo-11695.htm



Could someone explain to me what the arrow means? Why does it show a 1, then going counter clockwise, AGAINST THE ARROW, put a 2 in the upper left spot? I do not understand this arrow thing at all. I understand the NUMBERS... Is this diagram correct? It would make sense given how my old distributor was hooked up...

 

The diagram is correct. Firing goes clockwise with the arrow starting at 1. 1-3-4-2. The cylinders don't fire in numerical sequence. They fire according to the sequence on the distributor cap. The diagram even shows you where 1 is in relation to the cap screws.

 

The s10 only had the 2.5 and the 2.8 for 86 and 87. The 1.9 was discontinued in 85. The 2.0 was discontinued in 84.

 

I'm still not sure how the black and white diagram from the manual is supposed to help me AT ALL hook up the wires to the distributor cap. Maybe it wasn't meant for that?

I hooked them all up per the colored diagram, the thing purrs like a (really big) kitten. Especially with the new muffler. Got a new master clutch cylinder, bled it, works great - really great, very high clutch sensitivity, but the thing still grinds a little bit when going into reverse. No idea there. Only 115,000 original miles on this truck, so I'd like to take care of it.