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Jeep diagnostic help... with videos

Jeep diagnostic help... with videos

Flex BT

Senior Jeeper
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Location
Chesterfield, VA
Vehicle(s)
1981 CJ7. I6, Weber 38/38 with TEAMRUSH upgrade. T5, Dana 300TC, Dana 30 / AMC 20, True trac w/ 4.10s. 33" All terrains

Blue and rust colored.
I recently performed the team rush upgrade. New plugs, wires, dizzy stuff, etc. I really didn't notice a big difference in performance but I've also been wrestling with issues with my Weber 34 DGEC.

First up... I installed a new MSD blaster high vibration ignition coil today. The engine seems like it is running smoother but at lower RPM at idle! This video shows the RPMs sometimes bouncing a bit... what causes that and what do I need to look at to fix this? Does the timing need to change at all after these upgrades? It's at 8 degrees at present. Why would it be running at lower RPMs with a better coil? I would have thought the opposite.

Jeep CJ-7 tach after new ignition coil install - YouTube

The other thing is looking at my fuel pressure regulator. I have the Holley pressure regulator to keep my fuel pressure at 3.5psi as needed for the Weber 34 DGEC carb. The needle bounces from 3.5 down when the engine is idling but steadies up when throttle is applied. What might be causing this? I feel like it wasn't doing that a few weeks ago and I'm not sure what might have changed.

Jeep CJ fuel pressure gauge - YouTube

Thanks in advance for any insight you might have.
 
You might want to check the condition of the timing chain for that idle issue. This can be done by while using a timing light and watching to see if the timing mark on the vibration dampner bounces around. The more bouncing, the more slop you have in the chain. As for your initial timing 8 degrees might be o.k. but what I think you should be looking for is how much total advance you have, which should be about 28 degrees.
 
While your tac bounces, your engine doesn't change rpm. Looks like a dizzy issue. Make sure everything in the dizzy is tight.

For your fuel pressure, Hard to tell since you don't know if this was happening earlier. Doesn't look like an issue to me. Hard to keep a constant pressure at idle.
 
Try turning up your timming. On all my stuff I run as much as it can handel. If its not pingging you are fine.
 
What in the dizzy might be loose? The rotor just pops on, right? The cap is definitely locked on how it should be.

I'm hoping I might be able to advance it a little bit to try to solve the smell issue. It's still giving me an "unburned gas" smell after letting off of the accelerator. I've tried every combination of idle jet in this weber carb and it seems to get better when I use bigger idle jets and turn the mix down to about 2 turns out where it runs smoothest, but the smell is still there. I have the two biggest jets in it now that I could get (60 and 55).
 
Also, can I tell if there's pinging at a stand still or does it have to be under load? Can I do it with the vacuum hooked to the distributor and just max out rpms and listen for a ping?
 
With it all hooked up they way you run it if when you step on it that is when you will get the pinning. I just use the timming light to get a base then start giving it a little more at a time until it runs the best.
 

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