Rough idle and sputtering sometimes. Smog removal?

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Jroll522
Regular Member
Posts: 5
Joined: Sun Jun 07, 2020 8:32 pm
Location: Florida
Isuzu vehicle(s): 1990 regular cab 5 speed 2.3

Rough idle and sputtering sometimes. Smog removal?

Postby Jroll522 » Mon Jun 08, 2020 8:49 pm

I just bought a 1990 Pickup with the 2.3. It sat for a while from the previous owner. I don’t know much about it, I do know that the ac and air pump don’t have a belt going to them. Sometimes it runs great others it has a hard time idling and I can feel it sputtering while driving down the road but that’s only sometimes. I’ve put new gasoline in it and a can of sea foam thinking it might help out but so far it hasn’t. I’m looking to delete all the emissions and vacuum lines and adding a Weber carb but I’d like to get the ac back up and running as I live in Florida and it’s hot lol. Is that even possible? Is there a how to video or forum thread I can go to and follow step by step? I’m pretty good around fuel injected motors and diesels but this is my first carbureted. Any info would be greatly appreciated. Thanks!

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Red Truck
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Joined: Wed Sep 18, 2013 7:10 pm
Location: Vader, WA

Re: Rough idle and sputtering sometimes. Smog removal?

Postby Red Truck » Mon Jun 08, 2020 11:09 pm

Not to deflect from this forum, but "PlanetIsuzu" also has a lot of carb'd info. From what's posted, I'd start with a carb rebuild kit for the Hitachi, namely a new needle valve and seat. Also, I'd get about 6 feet of vacuum line and replace anything that appears remotely suspect. Bring a chunk of your old stuff to the parts place to get the right size. The EGR valve likes to stick, causing idle issues; that'll stay free with generous applications of WD-40. The air pump pretty much works with the cat-converter, and I assume that's going away, so I'd not worry about the air pump. Along with the usual plug, wire, and dist cap renewal, I'd start with that. Removing and plugging the air rail, etc, are covered elsewhere, but getting it running reliably would be my first concern before digging into de-smogging. Regards!
'87 Isuzu p'up 2.3 gas, 5spd, 4WD, base model, Fed spec

Jroll522
Regular Member
Posts: 5
Joined: Sun Jun 07, 2020 8:32 pm
Location: Florida
Isuzu vehicle(s): 1990 regular cab 5 speed 2.3

Re: Rough idle and sputtering sometimes. Smog removal?

Postby Jroll522 » Wed Jun 10, 2020 8:00 pm

Thanks for the info, although i busted a coolant line going into the heater core on my way home from work and caught it too late. Seems I have a blown head gasket. I’m debating just doing a full rebuild since it has 226xxx miles on it I feel that it would be worth my time since I’m already in there.