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Unread 02-17-2010, 12:47 PM   #1
Dborns
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1983 CJ7 
 
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Motor won't stay running

I've basically gone through and caught up all the routine maintenance on my '77 cj. Before, it would start right up and run pretty smooth. The changes I've made are new battery, new spark plugs/ wires, rotor and dist. cap, new fuel filter, air filter, oil, and all fluids. Since then, the motor turns over, but instantly dies. If I start it and keep it revved some, it'll run until I take my foot off and then die. I started it today, and stayed on the gas for about 10 minutes and it finally ran by itself.
I haven't gone through the carb because I don't know anything about that, but I'm sure it needs to be gone through by a mechanic. My question is, is there anything I can do myself anywhere else, that I can check myself before I take it to a mechanic?

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Unread 02-17-2010, 02:44 PM   #2
BioTex
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Check the timing, and check for vacuum leaks. When it is running, does it backfire? What gap are you running on the plugs?
Verify you did not get 2 wires crossed up. Make sure your fuel filter return line is pointing straight up.
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Unread 02-18-2010, 03:47 PM   #3
Dborns
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I have not checked the timing, but will try that if I can't figure this out any other way. I'm going to work on vacuum leaks tomorrow. When I have my foot on the gas, it does backfire a few times. The new plugs were gapped wrong first, but I removed them and re-gapped them to .035, (it has the amc 360). When I changed the plugs and wires I did one at a time so that I would not mix them up, but I'm not saying I didn't. I believe my Haynes manual has a diagram on how wires are supposed to go from the cap to the plug. I'm not sure what the fuel filter line is, but if its the hard line going into the fuel filter, then that is pointing straight up.
I really don't understand what happened; it was running normal, (but needed tuning), and after replacing all the appropriate parts, it won't run. I'm really focusing on the carb, since the choke is wide open even when cold, and that it does run fine after a LONG warm-up.
Also, I don't even know what kind of carb it is; it says Motorcraft so I was thinking a Ford carb. Any other suggestions?
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Unread 02-18-2010, 03:51 PM   #4
Fletch8672
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My 5 doesn't like the cold weather either. I usually have to stay on the gas for a few minutes when I first start it up as well, but after a few minutes, it runs fine. In the warmer months, it starts up & runs like a champ.
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Unread 02-18-2010, 04:10 PM   #5
Dborns
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I'm sure thats part of the problem. At the time I was able to drive it and it would start right up, it was alot warmer outside. But something isn't right b/c it takes almost ten minutes for it to run on its own. Again, I'm sure its just a carb in need of some adjustment, but it confuses me that it ran fine until I did all the maintenance.
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Unread 02-18-2010, 04:16 PM   #6
Dborns
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I'm doing some searching on here, (what a GREAT resource!), and another person posted the same problem. While his turned out to be bad gas, thats probably not my prob., but a person asked him about an EGR valve? Its supposed to be on a machined surface at the rear of the intake manifold on my V8. It doesn't show a picture, and I do have a machined area with a small hose going to it, but I thought that was my PCV valve. Does anyone have a subscription or pic of where to find the EGR valve on an AMC 360 V8?
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Unread 02-18-2010, 04:30 PM   #7
Dborns
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So what is the best way to check for vacuum leaks? I've read to use carb cleaner, but after reading some of the warnings I decided against that since I really like my home. Do I spray it around all the ports on the carb? I see a small hose about 3" long coming out of the back with a screw in the end to plug it. Theres also an approx. 1 1/2" connection coming out of the front with a "lip" on it that is for a hose connection that has nothing connected. But there are no hoses anywhere that aren't connected and again, I haven't done any work or disconnecting of hoses/ wires to the carb.
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Unread 02-18-2010, 08:00 PM   #8
sweet76
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I bet your new cap and rotor is causing the dist. to send the spark later and thus retarding your timing and causing it to run (or not run) like that. Sounds like mine when the initial timing is waaayyy low.
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Unread 02-18-2010, 08:53 PM   #9
TDHofstetter
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I'm thinking cap & rotor, too... too many times I've bought bum caps that simply wouldn't let the motor run right because of internal crossfire & bleedoff.

Is this point ignition or electronic?
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Unread 02-18-2010, 08:57 PM   #10
TDHofstetter
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Quote:
Originally Posted by Dborns View Post
I'm doing some searching on here, (what a GREAT resource!), and another person posted the same problem. While his turned out to be bad gas, thats probably not my prob., but a person asked him about an EGR valve? Its supposed to be on a machined surface at the rear of the intake manifold on my V8. It doesn't show a picture, and I do have a machined area with a small hose going to it, but I thought that was my PCV valve. Does anyone have a subscription or pic of where to find the EGR valve on an AMC 360 V8?
The EGR is a big (about 3" diameter) diaphragm inside a clamshell-shaped housing directly behind the carburetor. A fair-sized vacuum line should lead to it. Quick test is... get the motor started & crank up the fast idle screw so it'll stay running. With your fingertips, lift the diaphragm inside that housing (you can reach in from underneath, but only barely). When you lift it with the engine cold, the engine SHOULD STUMBLE. If it doesn't, the EGR could be jammed open all the time. This would be coincidental, having nothing to do with your tuneup.

If the EGR does make your motor stumble while it's cold, it's fine - forget about it & check something else.
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Unread 02-19-2010, 07:16 AM   #11
Dborns
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Is there anyway that my motor wouldn't have an EGR valve? I looked for what you described, and theres nothing in that area. If I'm looking at the motor from the front, the rear left side has a large hose coming out that goes to the water pump, the middle has a 1/2" hose that I assume is the PCV valve, and the rear right has nothing except a bracket for the carb wire. I found a pic of an edelbrock intake, and where it shows an egr valve, there is nothing on my intake.
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Unread 02-19-2010, 07:18 AM   #12
Dborns
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TDHofstetter- It is an electronic ignition. I did replace the cap and rotor, should I order another cap and try it? I changed the plugs and wires at the same time, so I really didn't check how it was running in between projects.
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Unread 02-19-2010, 08:32 AM   #13
TDHofstetter
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If that's an aftermarket intake manifold, it might not have the EGR. They're sometimes sold that way "for off-road use only" because a non-EGR manifold isn't compliant with emission laws. Another possibility is that the EGR was disabled by the previous owner because the EGR valve had started leaking. If that's the case, there should be a steel plate bolted down back there.

As to the cap & rotor... before you buy another set, I'd try putting the old ones back on. If it still runs ragged, that wasn't the problem. If it clears up, the new cap or rotor is your gremlin & needs to be sent back for a refund.

-- Tim --
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Unread 02-19-2010, 03:02 PM   #14
Dborns
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Hey Tim, thanks for the reply. I did find out that my motor does not have an egr valve, so that wasn't the case. A friend of mine came by and we did some work on the carb, and figured out it is junk. The choke is wide open all the time, and the cover on the choke adjustment "area", is riveted shut instead of the normal bolts. So the choke can't be adjusted. Also, the throttle adjustment is backwards and the high idle bolt can't be adjusted, so neither can the throttle. By taping the choke shut, and wedging a screwdriver in so that it was throttled up, the motor ran pretty smooth. There is also a pretty good vacuum leak around the base of the carb. So, the problem is with the carb, like a lot of people that posted said. Looks like a new carb is in my future.
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Unread 02-19-2010, 04:21 PM   #15
TDHofstetter
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Wow - all that... and it was running right before you did the tuneup???
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