Diagnose this....please

[okidoc]

87 GW. 360 2bbl. Recent rebuild (<1yr). Replaced egr,vacuum lines, carb to intake gaskets.
Checked for leaks: CTOs
Rebuilt: Carb (myself- probably problem)
Timing: correct
Ford TFI Upgrade(new wires, plugs, cap, rotor etc..)
Vacuum gauge reads 17hg w/ slight tremble when diagnostic carb cleaner applied to carb engine smooths out and reads good steady @ 20hg.

Symptoms: Starts easy, Idles in nuetral well. Idles a little rougher in gear. Stumbles around 1000-1500 rpm. Pulls well on Interstate. Can "jump" from light.
Disconnected transfer case and switch vacuum. A/C & heater vent controls and CC work well.
Float readjusted (9/16 from toop of bowl measured 1/8 from end of float)which probably created stumble but did not change fuel smell.

Major Symptoms: Strong gas smell, always from exhaust. Mixture control screws about 2.5 turns out. Carb cleaner produces good smoothing effect to engine idle when applied round carb main shaft and choke assembly.

Probable diagnosis: I'm thinking leak at or around main carb shaft( the one w/ the big butterflies on it). Or other vacuum source. Possible bad power valve? (less likely but still suspect). Sticky valves, however runs smooth at speed and accelerates as well as a 2 1/2 ton machine w/ a 2bbl should. No miss noted.


Help. I think I need to drop $200 on a new carb. Which is better the ford or the Holler in the 2150?

Thanks in advance. If we can't solve it at least we can laugh about it.

Dave S.

[David Simon]

Dave,
I run my mixture screws at a little less than 1 1/2 turns out and it runs fine. I used the directions from the tech section to tune it. I have a 1988 with a recently rebuilt 2150, rebuilt engine and TFI upgrade. Same initials, same rig, eary isn't it? Good luck.
David


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98 Cherokee (wife's)
97 TJ with all the goodies
88 GW
NP229/TF727/D44s
TFI Upgrade
Free-flow cat, Flowmaster 70, 2 1/2" exhaust

[okidoc]

I should be in Florida. I grew up in Sarasota- Yup! God's waiting room. The only place in the world you can get run off the road by a ninety year old woman and her mother.

I would like to run 11/2 turns but it won't run. Just kind of peters out. Choke appears to working normally too.

Thanks

It is eary.

[reddog]

Sounds alot like a vacuum leak to me. Use a tube on the carb cleaner nozzle to pinpoint where the spray goes and look there for your leak. If it is around the butterfly shaft you should be able to get a kit to sleeve it. Where the choke spring assembly attaches to the carb body there should be a small gasket to seal where the vacuum port is that sucks warm air over the choke coil spring. Rebuilding the 2150 is not too difficult, don't give up too easy.

Kerry

[nograin]

Same as Reddog!
It really does sound like a small vac leak.

[okidoc]

That's what I'm thinking too. I'm having trouble finding it, even w/ the straw on the carb cleaner can. Can it be an interanl carb leak that vents to the outside somehow? The only real tell tale I see from the carb cleaner is at the main shaft. Can that leak sufficiently to create a prob? There is only so much surface area to play w/.
Like I said I have rebuilt the carb, about 9 mos ago. But problem almost seems to be progressive. What are your feelings on Holley vs. Ford (both remanufactured). I could buy it, try it and take it back if I don't need it.

[reddog]

Yes the butterfly shaft can leak enough to cause problems. I have not seen that happen on a 2150 myself though. IMHO the motorcraft 2150 is a good carb if your going to stay with a 2 barrel.

Kerry

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87 GW - Stock (but it looks like RiverBeast when I'm sleeping)
TFI upgrade
360,727,NP229

[ClarkstonGT]

I agree about the mixture screws. 2.5 turns sounds like a bit much. Try 1.25 to 1.5. Also check the idle stop solenoid and make sure it is adjusted properly. If it is not adjusted properly, your idle will drop too low when you put the truck in gear or switch on the AC. You won't notice this when cruising.

[okidoc]

O.k. I dropped carb cleaner on the shaft on the choke side next to the carb body. Instant 20+hg and 50-100 rpm gain. I'm now leaning to bad shaft seal. Same on throttle side. Everything else seems fine. Anyone got an unwanted 2150 for cheap?

Thanks again for the posts