Engine will not idle?

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CrabFoam
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Joined: Wed Jun 27, 2018 11:59 am

Engine will not idle?

Post by CrabFoam »

Hi, I have a 1990 Grand Wagoneer (AMC 360 with HEI). It was running fine but had low hot oil pressure and blew some smoke at start up. Otherwise idled great and drove strong on the freeway and around town.

I pulled the valve covers and found pieces of the old valve seals. I used the pressurized cylinder method to replace the valve seals. No problems there and reassembly went well. All rockers torqued correctly.

I then replaced the fuel pump and rebuilt the oil pump. The fuel pump leaked a lot of oil out of its gasket and it seemed to put gas into the oil. I pulled the HEI distributor to get access to the flare fitting on the pump. Replaced the fuel pump and gasket no problem.

Oil pump was fairly easy. I pulled it, put new gears in and a mid plate as the cover was scored fairly badly. I put new oil into the engine and then primed the pump with a screw driver on a drill. It built pressure fairly quickly but I let the drill run for a bit to make sure all the oil flowed through the engine. Reinstalled the HEI distributor.

Went to fire up the engine and it runs really rough at anything below about half throttle. From half throttle to WOT it runs smooth like it used to. When it tries to idle is misses hard then abruptly dies hard.

Things I have checked so far:
1. The new fuel pump is pumping. Lots of gas in the carb bowl and the accelerator pump squirts.
2. Engine has 50psi cold pressure when its running.
3. Firing order. Triple checked this one.

Could this be caused by being a tooth off on the distributor? When I took it apart I marked where the cap and rotor was pointing at and I was certain to have reassembled it correctly. Anything else I should look for and double check?

Thanks!
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fulsizjeep
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Re: Engine will not idle?

Post by fulsizjeep »

Have you checked timing with a light yet? The HEI could very well be off a tooth.
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Topic author
CrabFoam
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Joined: Wed Jun 27, 2018 11:59 am

Re: Engine will not idle?

Post by CrabFoam »

Well it wont even idle so it is kinda hard to check it with the light.
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Stuka
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Re: Engine will not idle?

Post by Stuka »

Sounds like your timing is off. Have you tried turning the distributer while its running? It may very well be a tooth off, or its just turned way over. Or you may have a giant vacuum leak.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

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Re: Engine will not idle?

Post by BCRAWLER »

Start at the begining. Turn the engine to TDC then see where your rotor points.
1980 Cherokee,360/727/208, propane powered,unknown lift,31' Adventuro's on Chevy rims,Warn winch
1980 J10,360/standard/208, stepside
1970 GMC 4X4 Pickup, 78 frame, 84 350, Turbo 350/205, patina galore
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1990 Cherokee XJ, about to scrap for FSJ parts, gone to parts graveyard in sky

Topic author
CrabFoam
Posts: 16
Joined: Wed Jun 27, 2018 11:59 am

Re: Engine will not idle?

Post by CrabFoam »

Thanks everyone! The distributor was off. I put the engine at TDC and took the dizzy cap off and it was no where near the 1st plug. Reset it and now it idles great.
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Stuka
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Re: Engine will not idle?

Post by Stuka »

Good to hear :)
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ
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