1979 AMC 304 Rough idle.

[jafo]

Run your main battery GND to the top bolt of the starter! Have secondary GND's go to the frame and firewall. You want the same wire gauge as the battery cable is.
Don't forget the dash GND. You can use 10-12 ga. stranded there.
I also recommend secondary body to frame GNDs towards the back of the body on each side.
Do this before any other mods.
LG

I'm on it. I was looking at the alternator and found the main battery wire loose. I mean LOOSE. I've checked about every nut and bolt on this thing and am still finding stuff loose.

 

[Lumpy Grits]

The BIGGEST 'loose-nut', is usually hold'n the wrench or the steering wheel.

 

[jafo]

The BIGGEST 'loose-nut', is usually hold'n the wrench or the steering wheel.

That sir IS a fact!

 

[jafo]

Here is where I'm at.

I have ran the battery ground to the top bolt on the starter.

I ran a ground wire from the firewall to the intake. Junctioned off that at the firewall, is another ground wire running to the frame. All these are 4awg covered wire.

Next, I have a 12awg wire running from the battery terminal to the fender well battery side. I ran another 14awg wire from the front radiator support area to the same junction as the 12awg from the battey. I also ran a 14awg wire from the dash to the ground junction on the fender well. I will run two 14awg wires in the rear from frame to body each side.

 

[Lumpy Grits]

Move that firewall to intake GND to the engine block.
Run a lead from the block to the frame.
Doesn't hurt to run a dedicated GND from the altenator housing, to the engine block.
I do recommend the use of external star washers as they 'bite' into the surface. Coat these attachment points with battery terminal spray.
You are on the 'rite' path here.
LG

 

[jafo]

Done.

Ground rear each side body to frame.

Battery ground to top starter bolt.

Ground from intake to firewall then to frame

Ground wire from dash to ground.

Ground wire from front grill assembly to ground.

Secondary grounds all go to junction to ground directly from battery.

 

[Lumpy Grits]

Run the dash GND from the dash panel to the battery NEG(-)post.
Trust me on this.
LG

 

[jafo]

Run the dash GND from the dash panel to the battery NEG(-)post.
Trust me on this.
LG

Consider it done.

Took it for a drive and the engine had a bad miss. Came home and found that the no. 8 plug wire got pulled off somehow. It idles great when all the plug wires are on.

Overal, I can tell an.improvement. Slight, but I can tell. It still misfires in third on a hill though. Making progress. My headlights are nice and bright now also. Fixed my wiper switch, was loose. I need to get my washer fluid pump fixed also.

All in all, it's going in the right direction.

 

[Lumpy Grits]

How old are the plug wires and dizzy cap & rotor?
What plugs and gap are you run'n?
LG

 

[jafo]

How old are the plug wires and dizzy cap & rotor?
What plugs and gap are you run'n?
LG

The plugs are Champion RN14YC. Gap .035. New wires. The cap and rotor look new when I first started this project. I believe them to be fairly new. When I took the cap off it was way to clean and the bug had no wear marks. The cap was rhe cleanest thing in the engine compartment. So I never bought a new cap and rotor. So, age is unknown.

 

[Lumpy Grits]

OK-THX, didn't feel like search'n 17 pgs. because of my CRS.
I would replace the cap and rotor at this time. Make sure the new dizzy cap has brass terminal and NOT the alum type.
While you're at NAPA(YES-a hint). Get a new top of the line coil with ring terminals, and get rid of that OEM(POS)horseshoe connector.
Also have NAPA test your altenator, and give you a printout on amps and volts.

LG

 

[Belizean]

l

The BIGGEST 'loose-nut', is usually hold'n the wrench or the steering wheel.

I have to admit that was a good one! If your jeep has that much loose item you better go over everything on it

 

[Lumpy Grits]

l

I have to admit that was a good one! If your jeep has that much loose item you better go over everything on it

It's also the hardest nut to tighten down.......
LG

 

[jafo]

OK-THX, didn't feel like search'n 17 pgs. because of my CRS.
I would replace the cap and rotor at this time. Make sure the new dizzy cap has brass terminal and NOT the alum type.
While you're at NAPA(YES-a hint). Get a new top of the line coil with ring terminals, and get rid of that OEM(POS)horseshoe connector.
Also have NAPA test your altenator, and give you a printout on amps and volts.

LG

I'll pick up a new cap and rotor this week. I already have replaced the coil with a Blaster coil. No more horseshoe fitting, It's gone.

I'll get the alternator tested this week also.

 

[jafo]

Cap and rotor smoothed it out on the idle. That is for sure. But, it still has the issue. I really am looking at timing and carb. Or one or the other. Had a weird issue related lastnight. Pulled out of the parts store parking lot. Took off and it felt like it just didn't want to go then second same thing then something happened, and it just took off in third and ran fine. I drove it to work yesterday and it actually ran good coming home until my pitstop. I hadn't replaced the cap and rotor at that point. I did that after getting home. Drove it in to get the front end aligned today and it's kind of running as it has been. Kind of has that point taking off where you let the clutch out and it wants to fall on itcs face for a second and then goes. I just think either carb or timing.

 

[jafo]

Got the jeep back and all goes straight! No more lane hunting!

So we decided to play with timing again. Ir was set at 15* btdc. After replacing the cap and rotor, it made it a little harder to get it to misfire. So I decided to adjust it back to 7* btdc to start because it's close to factory specs. It got considerably worse. So wrong direction. I took it up to 20* btdc. Got much better, no spark knock, but the stater was dragging. So I backed it off a few degrees to 17* btdc. Starter drag is gone and so was the misfire. I tried to get it to do it, but just won't. Not saying in the right condition it won't, In the driving conditions it's done it before, it's not misfiring anymore. But it's still not right. Even though the misfire is gone, there is still a dead spot at wide open throttle. It's much better, I get more throttle with the timing change and cap and rotor, but it should have that flat spot with WOT. I also noticed keeping the rpm's at and above 2000 helps also with decreasing that flat spot. So I think there is still maybe a carb related issue here. So, I've decided that I'm going to drive it as is and it will be getting a fuel injection system down the road. I'd rather put the money towards that than spending it on a rebuilt carb.

So other than the flat spot, it's doing much better.

 

[Lumpy Grits]

Time to do a compression test and leak-down test before you throw any more $$$$ at it.
LG

 

[jafo]

Time to do a compression test and leak-down test before you throw any more $$$$ at it.
LG

Did the compression test on it already. Numbers don't jump off the page, low was 130 psi snd highest was 140 respectively. Most were in the 133 psi mark. Should be a break down of each cylinder in this thread some place. It was a dry test also. Leakdown test not done. But dur8ng the compression test, all cylinders seemed to hold there compression. Never done a leak down check. What procedure is there?

 

[jafo]

Ok. Decided to change thermostat today. Not to see if it helped with the problem but because I was tired of freezing my keester off. Found out as suspected it was a 160* stat. Went with a 190*. Also decided to adjust the idle mix screws one more time and got one more inch of vacuum. So it's at 19 at idle. Went for a drive and holy cow what a difference in manners. Takes off great, runs smooth and found a little more punch. I think the 160 stat was the wrong stat for this climate. I think the engine likes it warmer. It never got into the green with the 160, now it gets into the green on the guage. I think this will do it.

 

[Posi]

Yup, wrong t-stat should be 195, 190 will do.