Autozone rebuilt carb fail

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WattyWatts
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Isuzu vehicle(s): 1990 2.3L pickup carburated w/lot-o-smog crap

Autozone rebuilt carb fail

Postby WattyWatts » Mon Jun 29, 2020 5:17 pm

O.k. so i got to the end of my know how w/my 2.3 carb project. Went to AutoZone for a rebuilt one. Put it on, replaced lots of vac lines. I ended up with a surging idle. Long story short, the shop fixed the surgeing (vac leak@egr vlv) but can't get it to idle less than 2000 rpm.

WattyWatts
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Posts: 11
Joined: Fri May 22, 2020 8:38 pm
Location: Phoenix az.
Isuzu vehicle(s): 1990 2.3L pickup carburated w/lot-o-smog crap

Autozone rebuilt carb fail

Postby WattyWatts » Mon Jun 29, 2020 5:18 pm

O.k. so i got to the end of my know how w/my 2.3 carb project. Went to AutoZone for a rebuilt one. Put it on, replaced lots of vac lines. I ended up with a surging idle. Long story short, the shop fixed the surgeing (vac leak@egr vlv) but can't get it to idle less than 2000 rpm.

dorf
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Re: Autozone rebuilt carb fail

Postby dorf » Tue Jun 30, 2020 6:08 pm

Had a similar situation.....

Turned out. Carb mount not true, so was sucking air

Filed mounting surfaces flat......all ok....

Maybe a thicker gasket might solve your situation

Just my 2 cents

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Red Truck
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Re: Autozone rebuilt carb fail

Postby Red Truck » Wed Jul 01, 2020 10:56 am

Sounds like there's still a vacuum leak, following your other post about the EFE spacer. How about the PCV valve? Upon removal, it should rattle freely, and air should only go one-way when you suck on it. They're cheap, about 2 or 3 ducats. Is the distributor vacuum advance hose intact? Including the metal tubing from intake base?
'87 Isuzu p'up 2.3 gas, 5spd, 4WD, base model, Fed spec

WattyWatts
Regular Member
Posts: 11
Joined: Fri May 22, 2020 8:38 pm
Location: Phoenix az.
Isuzu vehicle(s): 1990 2.3L pickup carburated w/lot-o-smog crap

Re: Autozone rebuilt carb fail

Postby WattyWatts » Wed Jul 01, 2020 8:49 pm

No vac. Leaks per master mechanic at a very reputable shop.i had the original carb. Rebuilt. Shop installed that one...still surges. Two bad carbs...not likley. Btw the Egr was leaking, new gasket and fasteners were installed. Could a o2 sensor fail do this to the computer controled carb?

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Red Truck
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Re: Autozone rebuilt carb fail

Postby Red Truck » Thu Jul 02, 2020 11:15 am

You're out of my league IRT a computer controller, for this application. I didn't realize the 1990 truck had those, yet. It's certainly possible there's an issue caused by a failed emission component. Can you retrieve error codes off the computer? I once had a '91 Escort that I could read code numbers from, using an analog multimeter, and counted the number of needle swings. This procedure and error code numbers were from a Haynes manual.
Sorry I can't be of more help/Regards
'87 Isuzu p'up 2.3 gas, 5spd, 4WD, base model, Fed spec

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Red Truck
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Re: Autozone rebuilt carb fail

Postby Red Truck » Thu Jul 02, 2020 4:28 pm

I should clarify, after thinking about it: I didn't realize the 1990 CARB'd truck had a computer on it; those were pretty much reserved for the injected models. I believe you've got a Calif version so that would explain the computer-controlled carb setup. Geez. My Haynes manual has a procedure for pulling codes, but only if the vehicle has a check-engine light and fuel injection. It involves jumpering a plug connector and counting the number of flashes from the light. Alas, I doubt it would provide an accurate diagnosis for your rig. Again, sorry for not being any more helpful.
'87 Isuzu p'up 2.3 gas, 5spd, 4WD, base model, Fed spec

dorf
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Re: Autozone rebuilt carb fail

Postby dorf » Thu Jul 02, 2020 6:43 pm

I still say ....you are sucking air......somewhere

Spray oil..or other substance.....at carb base and around..listen for change n RPM

Let us know the fix

WattyWatts
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Isuzu vehicle(s): 1990 2.3L pickup carburated w/lot-o-smog crap

Re: Autozone rebuilt carb fail

Postby WattyWatts » Thu Jul 02, 2020 11:45 pm

Yeah the jumper is hangin off the computer. Behind the drivers side kick panel. Just blinks the all is good 12 code. I got it back from the shop. Idle still surges and a intermittent loss of power at speed is now present. Gonna try to emissions test it. Gonna dump it either way. To much hassle. Hope it passes....if not its gonna be a big loss. Thanks for the input.

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Red Truck
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Re: Autozone rebuilt carb fail

Postby Red Truck » Fri Jul 03, 2020 1:32 pm

I can't blame you; sometimes ya gotta cut bait with a vehicle. But now we won't know what the fix is!! Have you presented this issue on Planetisuzu.com? They ought to, at least, recommend a second opinion for another mechanic near you. I get the feeling that your guy kinda left ya hangin', there....In my limited experience with auto computers, a vacuum leak can cause a component to erroneously activate/deactivate resulting in poor performance, however the computer doesn't throw an error code because, well, the component is indeed working. I dunno, do the emissions test stations provide guidance on who to take it to, if it fails? Last time I used one was in Hawaii, and all it took for a 'pass' was a 12-pack of beer!
'87 Isuzu p'up 2.3 gas, 5spd, 4WD, base model, Fed spec