AMC 258 running on 5 cyl

Hey guys-


I have asked you about this before - my 1975 cj5 runs on 5 cyls, i think. it coughs a lot. back when i first asked, i was told to upgrade to hei ignition. but i can not find spareparts anywhere. so i was thinking of buying new cables, rotor etc.

But then i looked under the distributor cab, and everything looks new, except spark plug cables, and the coil.

Therefore i have attached pictures, and a movie where you can see how much the engine moves when running, and i hope you can hear the coughs.

Please help me out here - maybe i only need new spark plug cables, but im no mechanic. Btw. i have already replaced all six spark plugs.


I also took some pictures of my carb, looks like a weber, is that original?
There is a hole in the carb (marked red on picture) the carb sucks air into that hole, is that supposed to be that way?? The jeep smells a lot of fuel when standing next to it when it is not running, and when the jeep is idling aswell.

http://www.flamboyante.dk/jeep2/P1020843.JPG
http://www.flamboyante.dk/jeep2/P1020844.JPG
http://www.flamboyante.dk/jeep2/P1020845.JPG
http://www.flamboyante.dk/jeep2/P1020846.JPG
http://www.flamboyante.dk/jeep2/P1020847.JPG
http://www.flamboyante.dk/jeep2/P1020848.JPG
http://www.flamboyante.dk/jeep2/P1020849.JPG
http://www.flamboyante.dk/jeep2/P1020850.JPG
http://www.flamboyante.dk/jeep2/P1020851.JPG
http://www.flamboyante.dk/jeep2/P1020852.JPG
http://www.flamboyante.dk/jeep2/P1020853.JPG
http://www.flamboyante.dk/jeep2/P1020854.AVI

thanks - and regards from Denmark

 

Hello.Looks like a carter carb. The red circle is for a stove choke. Tube runs down to your headers or exhaust manafold . Heated air will be drawen up to carb to open choke.

 

the rotor is broken, but probably not causing your problem.
before throwing money at it, I'd do a compression test on all six cylinders.

 

what can we rule out from a compression test?
Posted via Mobile Device

 

Correct on the red circle. It will and should have vacuum at that port. If you are not going to install the heat tube, I would fabricate some sort of filter for it to keep junk from entering the carb. The coil looks like it is leaking oil from one of the terminals and if that is the case it should be replaced. Looks like the coil wire is not all the way into the tower cup. Can you run a compression test and post it here?

 

Compression test: Every body beat me to it.

 

Check your ignition module. Look behind it , if it looks melted it may be going bad. Are you sure that timing is set properly?

 

It may not be anything, but in the sixth picture, (# forty eight), it looks like there might be carbon tracking on the cap from the center coil connection to one of the plug wire connections at the three o clock position. Worth checking.

 

rings and valves mostly, with a few exceptions.
that gives us a solid start to look elsewhere.
if I understand you correctly, you're misfiring/not firing on one cylinder only, #5 correct ?
with good compression readings, we look at spark plug wire (check resistance with an ohm meter) and spark plug, getting spark, etc.
you do need a new rotor though

 

1#
Okay guys, thanks for all the good answers. Tomorrow i will buy a compression test tool, and make the test. I will write my results here. Is it correct that i should take all spark plugs out, install the compress test in one cylinder, run the starter for 15 secs, and then read the psi level?

2#
Rick:
What is carbon tracking? AM i good if i change the coil and all the spark plug cables?

3#
Rusty: SOrry to ask, where do i find the ignition module? How to set timing, and where ?

FIrst thing i will do is take the compression test, and then we can take it from there.

Can you please show me the heat tube? Because im not sure what it looks like, as i understand it controls the choker, with hot air from manifold?

 

The module should be on the pass. fender up by the rad. Running late . Will check back this p.m.

 

I just happened to notice a black line on the top of your distributor cap in the area I indicated in my previous response. It is when you get an electrical breakdown in the distributor cap that allows the spark to leak to a point that it is not intended to go, at the wrong time. They will show up as a black line, or carbon track, which develops as the continuous high voltage breaks down the cap material in that area into a carbon product. It's sort of like having a short circuit across two points that should not be there.
I saw a black line on your cap and it came to mind. The line could be dirt, I can't tell from the picture, but thought I'd mention it so you could at least look into the possibility.
If that's the case, you would have to replace the cap

 

Also from pic #48. it loks like your plug wires should be replaced....could be jumping a spark from wire to wire...

 

okay i will look at the dist. Cab tomorrow when i measure compression. Can you please confirm the way to take the test?
Posted via Mobile Device

 

For a first simple test, remove the ignition wire connected to the + (positive) terminal on the coil. Remove all spark plugs and block the throttle full open. Crank the engine through 5 (five) complete compression strokes (you will know a compression stroke when you hear it) and record the reading from the gauge.

 

The choke stove is nothing more than a copper tube from carb to header , These can be found in most all parts stores. They cost about 8.00 bucks here in the U.S. Lets wait on timing till you do your comp. test. Also the search function is your friend. For what it's worth, the prestolite is in my opinion very troublesome at best. I blew a lot of money on mine till I put in the H.E.I. One of the best mods I ever did.

 

Hey guys.

here is the results of the compression test:

Cyl nr - Bar

1 - 9 Bar
2 - 8 Bar
3 - 9 Bar
4 - 9 Bar
5 - 8 Bar
6 - 8.5 Bar

Are the results okay?

I looked closer at the spark plug wires, they are really banged - and also, im not sure if the wiring is correct. I have attached how my wires are connected - can anyone confirm this is okay?

http://img651.imageshack.us/img651/3717/unavngivetbo.jpg

 

1 bar = 14.5037738 pounds per square inch

1 - 9 Bar = 130 psi
2 - 8 Bar = 116 psi
3 - 9 Bar = 130 psi
4 - 9 Bar = 130 psi
5 - 8 Bar = 116 psi
6 - 8.5 Bar = 123 psi

 

When you are done with your comp. tests ...... leave coil wire off. You want to bring #1 cyl. to t.d.c. on the compression stroke. Do this by having a friend hold there finger over the spark plug hole. Turn crankshaft clockwise slowley using a 3/4 wrench or socket. When air pushes friends finger away from hole you are at t.d.c. No friend, use a cork placed in hole. Now check harmonic balancer. Your timing marks should be close. Pull dist. cap. Roter should be pointing to #1 plug wire. Now go in order clockwise around dist. 2,3,4,5,6.

 

a-ha. Okay. But the compression test is okay ?