more carb questions...

[homebru420]

Ok, I've done the requisite searches and read a whole bunch of carb problem threads here on the site and I'm hoping that some of you folks could clear some things up for a rank novice.

Recently bought an 89 GW whose prior owner clearly took a "laisse faire" attitude toward automobile maintenance...crying shame that so much disrespect was shown to this fine vehicle.

When I was first testing out the engine and performance (sophisticated testing involving letting it idle in my driveway while I wiggled and pulled on stuff and then ran it down the highway and then opened the hood and looked at stuff http://www.ifsja.org/ubb/smile.gif) I had a problem running rich. Culprit turned out to be a hole in the float bowl vent hose but may also have had something to do with the fact that timing was at 7* ATDC.

Now, I have a problem where when I start it after it's sat overnight...if I don't really rev. it for 5 - 7 minutes, it stalls when I put it in gear. Also, after I run it awhile and get it warmed up, I get "vapor lock-ish" symptoms even in mild weather...rough idle, loping to point of almost stalling before it picks back up again. Pulled the plugs and while they indicate a mild need for a valve job (slight oil deposits) it appears overall that I'm running lean/hot.

And here's what I've done so far...new fuel pump and filter (brown/black filter, low fuel pressure from wobbly pump arm), two oil changes with slick 50 to get rid of what must have been 15-20K miles of wear on exising oil (could've tarred my driveway with it), lots of hoses replaced (misc. vaccum leaks), new distributor, cap and rotor (dist bushings shot), new manifold air injection tubes (those crimped edges are sharp!), new charcoal canister (some idiot broke all the hose receivers off), new battery and cables (poor starting), new valve cover gaskets (bleeding all over the exhaust manifold), lots of little stuff. I put a new EGR valve on it before noticing that there's no cat but I've just left it there until I can find a machinist buddy to make me a cap for it.

Now, if I've got this right, that EGR is leaning out the mix by just sending in air instead of exhaust right? But this shouldn't matter at startup/idle in a cool engine right? That may be part of the issue but the carb is absolutely filthy! (It's the OEM 2150) Do the symptoms above (rough idle, stalling at startup, rough idle in gear when hot) sound like a carb issue? How much influence would the O2 sensor have on this? I've found lots of sand and dust on other parts of the engine as I've gone through it and the air filter that was in it when I bought it was horrendous...

I've eliminated (I think) obvious ignition and fuel system stuff...next advisable step is rebuild on the carb yes?

Anyone input on this would be greatly appreciated.

[joe]

Check and make sure the inline fuel filter in the eng bay has the vent nipple in the 12 o'clock/up position. I've heard this can cause vapor lock type symtoms plus it's a serious fire hazrad if installed incorrectly.
If while during your previous work did you happen to get a backfire through the carb? If so you prolly blew out the power valve in the carb http://www.ifsja.org/ubb/frown.gif

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Regards,
-joe
63 2-dr Wag, 72 J-4000, 73 J-4000, 82 CJ-8

[tuckers89GW]

First off, welcome to the group. You will find lots of usefull information on this board. Not to mention a great group of people.

You don't believe you have an o2 sensor. These things were designed well before computer controled vehicles and never really changed all that much.

From what read here, rebuilding the carb would be a good idea, especially if it has many miles on it and leaks. I haven't not personally done it yet, but I hear it is pretty easy job on the 2150.

First thing you should do is buy a repair manual. I have a Haynes and it is pretty good for most things. Better than Chiltons.

I know I didn't give much help, I'm sure others can tell you much more.

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Mike
<UL TYPE=SQUARE>
<LI>'89 GW
completely stock
<LI>'99 Windstar
under WARRANTY
<LI>see MY JEEP (http://tuckermj.tripod.com/jeep/)[/list]

[RudyC]

OK the "A" on the timing mark means ADVANCE as in BEFORE TDC (not After TDC). Yea I know its confusing that way but thats AMC for you. SO if your timing specs are supposed to be 7 deg BTDC it was right. You may have timed it in the retanded or after tdc side now.


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79 WAGONEER (SOLD IT, BUT WILL FIND A LESS RUSTY ONE LATER)
79 DODGE STEPSIDE, 318,HOLLEY STREET DOMINATOR INTAKE, 4BBL HOLLEY,TF727/275X16 GOODYEAR EAGLE GTS
pictures at:
http://albums.photopoint.com/j/AlbumIndex?u=1500380&a=11321052

[DerJeep]

I would suspect your choke and I doubt something as simple as adjusting the thermostatic spring housing will do it alone.

Check out this aticle, http://www.ifsja.org/tech/fuel/2150.shtml

and skip to the section after reassembling the carb, for choke adjustments (Choke valve clearance, fast idle cam linkage, bi-metallic spring setting, choke unloader, etc.)

I had a serious loping problem, which signifies a rich running condition, during warm-up. I had to adjust the choke pulloff setting and lean the carb a tad. I had the black residue on my spark plugs prior to these adjustments and now everything is A OK.

[Brazzy]

I gotta agree with the btdc post 7 ATDC would prolly not be possible, wouldn't run!!
The other culprit could be vacume leaks check all yer hoses and fittings there again, it's easy to miss a loose fitting. Then use propane(unlit of course) around the base of the carb and intake joints it'll increase the idle if it leaks. Save the carb rebuild for last. Hope this helps!

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Brazzy
Formerly abused 87 G.W. 175k
TOW,PKG,727,229,360
2.5" Rancho softride AAL
The Chariot

[nograin]

well you didn't write "PCV Valve" and hose, thats your biggest potential location for oil getting into the intake systems and for big vacuum leaks. There is a special molded s hose for the hook-up.

OK. I'll buy the A stands for advance, it certainly is BTC, and 7 degrees sounds low, try more like 10 at 600 rpm, and the vac adv. line plugged. (you should have a spec in the engine compartment if you are lucky).

EGR does the opposite of what I think you are saying. Working right, it dilutes the air/fuel mixture with unburnable exhaust gas when ported vacuum is medium to high. That is at all times except idle and wide open throttle.

Carb. If the fuel going in looked as awful as you described, then absolutely do a thorough internal cleaning of the carb. I just had to redo mine, cause there was still some little bits in the bowl wells that were getting into the little passages. It only takes one to mess up the operation. Mine was lodged in an idle fuel feed channel.

Basically you just need to clean it, replace any bad gaskets, and other parts that are shot. I used the Borg-Warner kit. It was OK but not impressive. Try the Holley kit, its cheaper, and might be better. In the recleaning, I didn't replace anything so another kit was not needed...just more carb cleaner.

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360 727auto-trany, NP229
body by beer (PO) :(
carries wood inside
no "wood" outside
http://users.erols.com/mathewg/85gwsmll.jpg
My other car is a fish

[homebru420]

Thanks for input everyone....

First...sorry for the timing snafoo...I've got it advanced 12 degrees according to TSM specs at this point.

I have indeed replaced the PCV valve and hoses...twice. Only took 1K miles after the initial "sludge" change to plug it again but oil seems much cleaner and free flowing now.


NOGRAIN - The EGR does indeed function the way you state when the cat is hooked up...however since I have pulled the cat and have just the exhaust return tube hanging down from the EGR, my thinking is that it's just injecting fresh air instead of exhaust back into the combustion chamber...thus leaning the mix.

After several consultations...concensus seems to be on two things: FSJ's rock, and I should clean the carb/check the choke.

Off I go for the rebuild kit.

Brian

[joe]

<BLOCKQUOTE>quote:</font><HR>Originally posted by homebru420:
After several consultations...concensus seems to be on two things: FSJ's rock, and I should clean the carb/check the choke.

Off I go for the rebuild kit.

Brian<HR></BLOCKQUOTE>

Brian, if you haven't yet done so read the excellent article written by Micheal Baxter on rebuilding the 2150's. It's on this web site in the /TECH/ section. Well worth reading.

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Regards,
-joe
63 2-dr Wag, 72 J-4000, 73 J-4000, 82 CJ-8

[homebru420]

That article should be placed among the classics of FSJ literature right next to the "How to troubleshoot your electric tailgate window and take apart your tailgate".

Many thanks and good jeep karma to all who contributed...now armed with tech articles, Haynes, and original TSM's...

...stay tuned as I'm sure I'll find a way to screw this up.

B
proud owner of "My Migraine"

[nograin]

Yes & No,
I now understand what you were thinking about with tthe EGR, and we are on the same page.

But, The tube to the cat is the AIR injection tube. As best I can tell. the EGR gets its exhaust through the intake manifold which in turn gets it from little passages in the exhuast ports. When the EGR valve opens, the e comes out the holes in the plenum under the carb. You can see the holes when you pull the carb if I remember right.

[mahlmann]

A good place to start with prioblems like this is to suspect ....ta da.....VACUUM LEAKS, the bane of FSJ's everywhere. You need to know what your vacuum is at idle. It should be a steady 20 - 22 inches. If it isn't, you need to find out why and fix it. I have a Sun Pro hand vacuum pump with the brake bleeding attachment and it has saved me a ton of time trouble shooting problems on my Waggy. Highly recommended. Let us know what your vacuum condition is, and we can make some suggestions on where to look next.

Good luck with it!

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Mike Ahlmann
'87 Grand Wagoneer
"Steel Brick"
Sunnyvale, California

[homebru420]

I've got a hand vac. pump...where do I attach at idle? Manifold vaccum port behind carb, or over at the little multi-port thing near passenger side firewall?

[RudyC]

Manlmann,
No way thats way too high vacuum at idle for most older motors 15-19 is more the average from prior post readings and my own. I ran 15-16 on my two year old rebuilt 360.

Attach the vacuum guage, yea I use a hand pump too, to any place that has manifold vacuum at idle. I you have the power valve cap with the vacuum hose on it you can use a t fitting on there.


------------------
79 WAGONEER (SOLD IT, BUT WILL FIND A LESS RUSTY ONE LATER)
79 DODGE STEPSIDE, 318,HOLLEY STREET DOMINATOR INTAKE, 4BBL HOLLEY,TF727/275X16 GOODYEAR EAGLE GTS
pictures at:
http://albums.photopoint.com/j/AlbumIndex?u=1500380&a=11321052