I'm Rich!

[59toaster]

did you happen to mess with the adjustment under the primary rods?
http://www.carburetion.com/Quads/M4MC-E.htm
Its under pt #47 and 48 down in the hole they sit. It has a funny head on it and you would have had to remove it with needle nose plyers or might find the spedial tool to take it out. It controls how far the rods drop.

[swebster]

Originally Posted by 59toaster

did you happen to mess with the adjustment under the primary rods?

nope. opening up the carb today to check everything mentioned in this thread. i'll keep you posted.

[ALANSD]

While you are mentiong Jeg's have you seen the rebuilt Edelbrocks there..they are fairly priced...might be a good choice if all else fails..but hang with the Q-jet...for awhile it will hopefully come together for you.
Mine was running quite rich until I cleaned the heck out of it and ran a few bottles of Marvel Mystery oil thru the tank. I run that stuff thru every few tankfuls. Its a mystery, but my dad used it for decades and I'm kind of stuck on it. I know yours is already clean, but a small piece of garbage somewere can really screw up the adjustments.
By the way, to those who follwed my fuel filter replacement recently, when I switched it around ( the carb one) the whole situation changed, from chokin' and stumblin' to clean and smooth. Sure felt stupid, but so it goes sometimes.

[Janets Husband]

Originally Posted by swebster

I'm really hoping to keep this carb long enough for me to fund an FI conversion next year. Hate to spend the bucks right now on something I don't want to keep.

Now your on to something. The FI replacement is the way to go.
The money you'll save in gas mileage alone will pay for the replacement in a year or two.

[swebster]

I "may" have found the problem; well at least I found one or two problems. Here is what I discovered when I opened up the carb:

When I started to take apart the carb I noticed that two of the base plate screws were fairly loose. Not sure if that caused any issues but it made me wonder about leaks. When I opened the top I noticed two things; first the primary needle hanger (see #47 on Toasters' reference) was slightly bent up on one side. Well that sure could cause some problems. Secondly, I noticed that there was a little retaining cap on top on the power piston which was loose, actually it was sitting up on top of the casting and prevented the primaries from fully closing. I did not find an debris in the seats but thought I might have found the problem already.

Nothing else seemed strange. Sealed up the fuel wells with JB Weld and cut out the idle mixture screw plugs (a while you're there kind of thing). Straightened the primary hanger and made sure the little retainer was seating properly. Reassembly was pretty much by the book from there.

Just for good measure I replaced all of the plugs with AC Delco R44T's and did an oil change.

OK, I may have inhaled a few too many gasoline fumes but...I think I got it.

When I started her up everything was different. First off the engine fired up right away without any of the usual cold start stumbling. Also, there was no smoke coming from the exhaust on high idle. (BTW - the high idle and low idle points were all off at 2400 and 1000 rpm respectively.) I let the engine warm up and took her out on a quick drive on local roads. Things seemed fine so I took her out on the highway for a loop around the city then back to the office. I let her cool down and pulled the number eight plug expecting to see a lot of soot. Now the plugs were literally brand new but to my surprise the plug looked great. A little brown tip and clean.

Now this is only a 10 mile test run so I'll know for sure next weekend when we head to Cloudland Caynon. Hopefully the bent hanger and unseated cap was the problem but I figure if its not fixed, at least I'll be surrounded by a lot of AS owners with a ton of opinions about carburators in only six days!

Alan - I certainly was looking at those carbs on Jegs.com. I also noticed that they now carry those Jet rebuilds for around a good price as well.

Gary - I go back and forth on the carb/FI thing but the more I think about the more that Edlebrock FI kit seems like a good idea.

[59toaster]

Got to love obvious problems!

Ohh here is a teaser. FACTORY Spread bore GM FI. This is sitting in a box and was going on my GMC but now its ear marked for a 455 for my 1970 Pontiac. I have two of these. the other one is on burb you rode around in.

Isn't it pretty? It will bolt right onto your existing intake and it will use the signall from your VSS for your existing cruise control.

87-89 454 trucks with the body like my Burb is what your looking for in the junk yard. Its harness is nearly a drop in like a Aftermarket because it was retrofited to the old body. The harness is not tied into any of the other harnesses except for the power leads.

[ALANSD]

Good deal, seems you probably cured it. Be safe on the road this week.

[swebster]

It will bolt right onto your existing intake and it will use the signall from your VSS for your existing cruise control.

Junk yard bolt in fuel injection? Now you're talkin' my language! Tell me more!

[George]

Originally Posted by swebster

Junk yard bolt in fuel injection? Now you're talkin' my language! Tell me more!

Steve,
Glad you found it, sounds like the the primary needles were never able to fully seat in the jets.
this is the "power valve" system in the Q jet.
Without the needles fully down in the jets, it was running rich all the time.
About the only time it was "right" was when it was at full throttle.
you will see a good improvement in mileage.
Just to note:
Since we have gone to unleaded gas, the "Exhaust pipes" don't burn that light gray that used to years ago, (that was lead deposits) they are a dark chocolate now.

Watch out, you just might like the ol Carb system!!

[59toaster]

Originally Posted by swebster

Junk yard bolt in fuel injection? Now you're talkin' my language! Tell me more!

http://www.customefis.com/
John is painfully slow on filling orders on full systems but he has the information you need to make your own "Kit" from an existing FI. The key to make it easy in your case is pulling a system from the years I posted. I bought my system for $250 to get the ECM, Factory Harness, Throttle body and most of the sensors. What I will need a a fuel pump making the correct fuel pressure and a O2 sensor.
That will get me a system that will run. Now the factory system did run a "FI" cam BUT with the ADSL cable and a laptop or in your case just plug into your onboard computer you can data log the system. John can then burn you a chip tailored to the engine needs.

In addition to my Suburban that system was used on Crew cabs of the same body style and Vans. The Vans are a nice find because they have a longer harness to reach under the driverseat. 90 they changed the intake to something closer to the 350tpi. It can be used but you will have to make an adaptor. John wil sell an adaptor but its still not s smoth flowing set up like the previous set up like I pictured.

Here are a few other links.

EFI TBI TPI Fuel Injection:
www.jagsthatrun.com (FI conversion stuff)
www.tpis.com
www.fuelinjection.com
www.tunedport.com
www.thirdgen.org
http://216.121.161.76/files/GMError.pdf (GM Computer error codes)
www.autoxray.com (scanner for FI vehicles)
http://www.thirdgen.org/newdesign/te...imatetbi.shtml - TBI Air Cleaner Mod
http://www.thirdgen.org/newdesign/te...matetbi2.shtml ? TBI
http://www.geocities.com/ecmguy.geo/
http://216.121.161.76/files/GMError.pdf
http://www.customefis.com/index.html
http://www.howell-efi.com/ (harness kits too)
http://www.autoxray.com/scanners.htm
http://www.fastchip.com/ (don?t know anything about these guys)
http://www.goingfaster.com/spo/tbi.html
http://www.thirdgen.org/
http://www.tpis.com/
http://www.tunercat.com/
http://www.fuelinjection.com/
http://www.winaldl.webhop.net/ (highly recommended for laptops)
http://www.thirdgen.org/.
http://www.chevythunder.com/ TPI Conversion For 85-92 TPI

[swebster]

We just returned from a 650 mile round trip for the forum rally in GA. Seems like we have this running rich issue licked (FINALLY!)

Ran well the entire trip, pulled hills with no problems, the rich smell and black sooty smoke was gone, and we made it there and back on just under one tank of gas.

The "back of the napkin calculations" came in at 8.7 mpg! Way better than expected pulling some long steep grades in Tennesse and Georgia.

Thanks to everyone for the input.