I have a '74 2.0L with FI...

Everything = Great
Changed Spark Plug Wires (one at a time - all the wires are connected correctly)
Everything = Not great
Changed Spark Plug Wires Back = Not Great

Checked all wires with a spare plug and I was getting 1/2" arc to ground...(Spark = Good)

Obviously the engine is running rough!
I can pull off Plug #s 1 & 2 and the engine runs exactly the same. If I pull off Plug #s 3 & 4 the engine dies.

Timing = Right On
I changed spark plugs 1 & 2 just in case....no change

I started messing with the fuel relays. It didn't seem to change ...

Also, there is no heat on the Driver's side of the engine. It is pretty cool compared to the passenger side.

What the deuce is going on here...?

did the #1 and 2 plugs smell like fuel before changing them? or dry?

QUOTE (rogergrubb @ Sep 21 2005, 04:27 PM)

did the #1 and 2 plugs smell like fuel before changing them? or dry?

I never really (even now) detected any fuel odor. From the plugs or otherwise.

Any idea? Anyone? Bueller?

If I remember right (don't count on it), the trigger points (of which there are actually two) control injectors on each side. I'm sure someone will correct me if I'm wrong. But that's where I'd start to look.

Do a search for trigger AND points and see hwere that teaches you.

from what i understand, trigger points fire diagonally.....

trigger points squirt diagonal cylinders...correct....maybe you got the plug wires crossed somehow?

Check that it's getting fuel from those cylinders. Either sniff the plugs the next time you pull them out, or better yet stick the injectors into jars and observe the spray pattern.

Check the compression.

After that, the only variables are "how much fuel", and "when is the spark happening".

Injector points pair the cylinders diagonally. I think the grounds have the front two paired, and the rear two--but I'm not certain about that. Worth checking the ground point at the rear of the crankcase seam.

EDIT: Yeah, check the #1 and #2 plug wires. Remember, #1 is the left-rear plug, and it connects to the left-front distributor cap tower!! Easy to forget that and connect the left-front to the left-front one...

--DD

Injector grounds are common to each side. So cyl 1+2 injectors share a ground and 3+4. Sounds like your common injector ground is suspect.

I don't see how I could've gotten the wires switched. I can pull off the 1&2 Plug Wires and the way that the engine runs doesn't change!

The plugs were black and charred, but they did not smell like fuel.


I am not sure about this diagonal squirting thing... What is this all about 'trigger points'...?

D-jetronic injection opens the injectors in pairs. So the #1 and #4 injectors open at the same time--when the #1 intake valve is open. The fuel charge just sits there in the intake port on #4 for a half a crankshaft revolution, until the valve opens and sucks it into the cylinder. D-jet info can be found here: http://members.rennlist.com/pbanders

Check the grounds, like Bowlsby suggested. Also make sure the left-front distributor cap tower is connected to the left-rear cylinder.

--DD

Try swapping the plugs around and see if the problem follows the plugs.

How'd this turn out?

jb

Pull the covers back, on the wires at the dizzy. Feed them into the holes, then pull the covers down..

I bet the wires aren't seated... it's a 2-step thing.


M

All, thanks for the advice...!

There are three ground wires coming out of the 'gray' harness near the rear of the engine. These ground the injectors. One of these wires had come loose...

Simple as that...

I just wish it hadn't taken me a week to figure it out!