cylinders not firing

[dc914guy]

Two of the cylinders on my motor (75 2.0) are not firing at all now. You can remove the plug wire, or the fuel injector wire with no change.

It is the two cylinders closest to the impeller (2 & 4 I think) where is a good place to start diagnosing? New cap, rotor, and plugs.

Thanks,
~Eric

[Biggy72]

well you could make sure you're gettin spark first of all and then go from there.

[John Rogers]

I'd check the spark and the signal to the injectors. Pull all the plugs, attach the wires, ground the plugs and crank the engine to see if each sparks? If not then troubleshoot the distributor. Pull each injector, connect the wire leads and then put each in a bottle. Crank the engine to see if the injectors are firing, if not then it could be trigger points or wire problems or plugged injectors. Good luck.

[norustscott]

valve adjustment??? a tight valve will have the same affect as a dead spark cylinder

[castlesteve]

If you ARE getting spark, then check THIS :

I had the same problem when i first bought the car... and every mechanic over looked this (that why i picked up a cherry 74-914 w/ 50k miles for DIRT CHEAP).

Locate the RESISTOR BLOCK. (I assume the 2.0 also has this...?) The RESISTOR BLOCK is the aluminum assembly with 5 white wires connected. RESISTOR BLOCK is near the battery/computer. The fuel injectors run in series to this... and if you look close, you may see a wire has snapped off... each wire is one cylinder. Solder back and away you go.

http://www.pelicanparts.com/gallery/castlesteve/

[Kenny Powell]

Steve, I think the resistor pack is only on 1.8 FI systems.........I had a problem with one once, can also cause intermittant stalling and starting

[Dave at Pelican Parts]

Check for spark as was suggested earlier.

Check for fuel. You can stick the injectors into glass jars and have someone crank the starter to see if you're getting fuel. You can plug a "noid" light (available for cheap at many FLAPS [Friendly Local Auto Parts Stores] or for 3-4x as much on evil-bay as a "fuel injection tester") into the injector connectors and see if they get electrical signal.

Next, I'd check the compression. A flat cam lobe will affect two cylinders on the same end of the motor (both front or both rear ones). If the problem were diagonal, I'd suspect the FI trigger points and related circuits. If it were left/right, I would suspect the injector grounds on the rear of the case seam.

--DD

[Biggy72]

you knwo last time I went to go racin with my bumblebee (cheap 4 cylinder cars racing on a weird road course type deal on an oval) I was down one cylinder starting the heat, but I still had enough power to keep up. When coming to the green I lost another cylinder, so I couldn't even keep up with the pace car. I raced all night on two cylinders and got 12th out of 18 cars cause everyone else either broke or got black flagged.

Found out after the race that two of the rocker arms had fallen off and I had one lifter come apart. It'll be interesting to see how fast I am on the 4th and 5th of july now that I've got it all taken care of.

[chrisreale]

Dont trigger points fire 2 and 4 , 1 and 3? Maybe thats your problem?