CJ7 Stalls

CJ7 Stalls
G

Gus

Jeeper
Posts
52
Thanks
0
Location
Mountain Home Idaho
Vehicle(s)
86 CJ7, 4.2L, T-5, Dana 300, Dana 30/Dana 44, Weber 34 DGEC
My CJ7 /AMC 258 i6 / 4.2l (owned for approx. 1 month) keeps stalling when I press the clutch in and come to a stop, this is with the engine being warmed for approx 10 minutes. The PO disconnected the whole emission system. Initially the CJ was dieing while driving down the road at approx. 2500-3000 rpms in 3rd. I did a TeamRush upgrade(I-6 'TeamRush Upgrade' (definitive) - JeepForum.com) and I did the Nutter Bypass(The "Nutter" Bypass), and that problem has disappeared. The PO installed a Weber carb. The only vacuum lines attached to the carb are the: breather hose going to the carb adapter plate from valve cover and the vacuum line coming from the distributor. I have recently replaced the fuel filter (the return to tank type), because I thought that it might be causing the issue, I also have a pressure regulator installed after fuel filter set at 3.5 psi. I checked the timing and with engine warm and the vacuum hooked up from the distributor it sits at 8*. Does anyone have any ideas or experienced this?

Thanks ahead of time,
Gus
 
the same happened to me on my AMC 304 . i had a motorcraft carburetor. i replaced it and nomore problems. but if i was you look at the howell fuel injection system. pricey but you wont regret it.
 
Last edited:
There was a member here that said with the weber and the pressure regulator, you do not want the return type filter... Im not sure the particulars on why, but i remember reading it...
 
What is your engine vacuum at idle?
 
JR,

I will do some searching on the forums for this setup. Thanks,

Posi,

The vacuum guage reads right at 12 and doesn't move until throttle input. According to this website (Browser Warning), since I am 3300 feet (drop 1 for every 1000 feet) it would normally read approx. 15. When I give it gas it drops to 0 and I am actually able to get it to stall by moving throttle linkage quickly approx. 1/2 to 1 inch.

Thanks,

Gus
 
Last edited:
Gus said:
I checked the timing and with engine warm and the vacuum hooked up from the distributor it sits at 8*.

Thanks ahead of time,
Gus
Click to expand...

Need to clear this up. Did you check the timing with the vac. line hooked up or unhooked and pluged.?
 
Old Dog,

All vacuum lines where hooked up, that the PO hooked up...lol.

I went to the local NAPA and they said check it without the brake booster hooked up. I disconnected the brake booster and plugged with thumb and PSI went up to 13 but did not have any more "stalling" and needle never hit zero when engine RPMs increased.

JR,
I did find the post you were talking about (http://www.jeep-cj.com/forums/f2/weber-carb-fuel-retrun-line-5875/). Changed the fuel filter to non-return style.

Also, I installed a Fuel Pressure gauge (http://www.oreillyauto.com/site/c/d...eyword=gauge+fuel+pressure&pt=N0529&ppt=C0134) after the pressure regulator and filter to make sure that I am getting enough pressure into the carb, but I am not registering any pressure? I am thinking a bad gauge. When I turn the regulator down to 0 the engine dies due to no fuel.

Thanks,

Gus
 
Last edited:
Gus said:
Old Dog,

All vacuum lines where hooked up, that the PO hooked up...lol.

I went to the local NAPA and they said check it without the brake booster hooked up. I disconnected the brake booster and plugged with thumb and PSI went up to 13 but did not have any more "stalling" and needle never hit zero when engine RPMs increased.

Gus
Click to expand...

The vec. line to the dist. should be unhooked and pluged when you set the timing.

It sounds like your booster might not be holding vac. pressure.
 
I will re-accomplish timing tonight, I didn't realize that was how it was to be accomplished.

Does the booster have replaceable seals?

Thanks for the input.

Gus
 
Sorry, not sure on the booster, I've never had one apart or know if they come apart.:confused:
Hopefully someone will enlighten us.
 
Gus said:
JR,
Posi,

The vacuum guage reads right at 12 and doesn't move until throttle input. According to this website (Browser Warning), since I am 3300 feet (drop 1 for every 1000 feet) it would normally read approx. 15. When I give it gas it drops to 0 and I am actually able to get it to stall by moving throttle linkage quickly approx. 1/2 to 1 inch.

Thanks,
Gus
Click to expand...
12 is too low. If your at 3300 feet you should be around 14-18 psi. I would check the remaining vacuum lines for cracks. Then check all around the intake manifold, carb base, and carb it self for vacuum leaks.

A typical way to check for leaks would be to use an aerosol spray i.e. carb cleaner or starter fluid. While the engine’s at idle spray the suspected areas if there were a leak the engine would ingest the spray and the RPM would change and you would have found the spot.

Something that really works good and what I use is propane (do not light). I find it clean, and fast working.

Hope this helps.
 
I have a Weber 38 and have developed a significant fuel leak on the passenger side of the carb. Troubleshooting will have to be placed on hold until my rebuild kit gets here. What are the possibilities it sucking air in at this arm? LOL...thanks for the help, I will repost after the new seals are placed in the carb.

Gus
 
Hey everyone,

I have some updates. I started a new thread for the vacuum setup (http://www.jeep-cj.com/forums/f2/vacuum-system-setup-questions-11380/#post91492), but in the process have found out that when the brake booster is disconnected and the line is plugged the Jeep still stalls. Also when I fixed the PCV setup my vacuum dropped from 12 to 5. So I sprayed carb cleaner around after it warmed up and found a leak at the base of the carb plates. Can I get replacement gaskets or can I just cut some gasket sheets or can I use gasket maker?

Read more: http://www.jeep-cj.com/forums/f2/vacuum-system-setup-questions-11380/#ixzz1c74zqh1A

Thanks,
Gus
 
You can't buy a booster diaphram, so you'll have to find a rebuilt unit. If you step on the brakes in your driveway with the Jeep at idle, does the Jeep die? If it doesn't, then your booster is fine. If it does, you've found your problem.
 
It does not die, I even plugged the hose and took it for a drive with no power brakes and it still died when stopping. I found a leak around the adapter plates for the Weber carb, hopefully it fixes it when I reassemble everything.

Thanks,
Gus
 
You can use premade gaskets or cut from sheet... If by "gasket maker" you mean like the liquid pasty stuff i dont think its good near fuel...
 
UPDATE: Replaced the three gaskets on the adapter plates and carb. I guess I still have a leak because it still sits at 5. :down::down::down: I believe the EGR is leaking but I will try to block that off tomorrow.

Gus
 
You must log in or register to reply here.

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a donation.

Help support Jeep-CJ.com by making a donation.
Goal
$200.00
Earned
$0.00
This donation drive ends in
Donate
Back
Top Bottom