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Old 01-29-2010, 10:45 AM
chirorod chirorod is offline
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I have tq 9002 on my 86 5th av. It runs pretty well warm, except it could use a little more power. I got this from a guy in New York. I put it on to try. It wouldn't idle but had great power at wot. Took it apart. Had tons of crap in it. Cleaned it out. Found that that the inner tubes (I'm calling them inner tubes for want of the proper name) in the primary circuits were completely plugged. they look like tiny brass pipes. Good. that was the reason for no idle. Put new well seals in it. Put it back on. Idle cured. Very smooth idle. Decent power but less than before I took it apart. BTW, didn't change air door setting. With outside temp above 55F, starts beautifully. It starts before the first revolution is finished. Below that, have to pump throttle 40 or times, then starts and stalls. More pumps, starts and idles on fast idle, but stalls when put in gear. After idling 2-3 minutes, drives and doesn't stall, but no power for another few minutes. Then drives but no big power for maybe ten minutes. I notice that it has what I think is an idle enrichment doohickey on the front of the carb. I didn't hook it up at first. Then I ran manifold vacuuum to it. No real difference. Any ideas on hard starting cold?
The car is 86 5th av. stock 318 with the following exceptions. 4bbl manifold off a 79 360 in a Dodge motor home. 9002 tq. Custom made kickdown linkage. Summit square coil. Summit 8mm wires. Distributor with vac and mechanical adv. Initial timing at 14 btdc. I don't have a degree timing light, but timing adv estimate is 32-36 degrees from marks I put on balancer using timing tape. Summit timing chain and gears. Summit 6901 cam. edelbrock lifters. New choke pull off (which may be reason for somewhat less warmed up power. haven't adjusted that link yet).
New autolite 65's. I increased the gap to .040 to see if that made any difference. No difference.
Thanks in advance for your thoughts.
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Old 01-29-2010, 03:18 PM
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pcrmike pcrmike is offline
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Sounds like no choke.
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Old 01-29-2010, 06:27 PM
chirorod chirorod is offline
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It does sound like no choke, but choke is working and adjusted. And fast idle is working. It seems to me that it is too lean, so even with choke, still not enough fuel. We used to run a Triumph TR3 in sports car racing that we had removed the choke from. It would still start. Had to keep working the gas until it warmed up, but it did start.
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Old 01-29-2010, 09:13 PM
dodger1 dodger1 is offline
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I don't have any suggestions, mainly because my rebuilt TQ has developed almost the same symptoms - instant fire at ambient temps over 50F, much pumping while cranking in cool/cold weather, or after being parked for a week or more. Re: the lower full throttle power - did you know that the choke pull-off also damps the opening rate of the secondary airdoor? That may have changed the feel of the secondary opening and maybe you want to set up the door spring a bit looser to compensate. I think the doohickey on the front was an idle "enleanment" device for altitude compensation, but I'm not sure as mine came off a Can. market 78 truck and had no smog stuff. Hopefully our resident TQ guru will chime in here?
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Old 01-29-2010, 11:49 PM
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Where is demonsizzler?
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Old 01-30-2010, 08:46 AM
chirorod chirorod is offline
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Dodger1
You're right about the link to the air door. I just hadn't got around to that yet. Want to take care of the cold start first. I did a little more reading, but all I came up with is the 9002 is a 76 model, with more leaning out for emissions considerations. And the device mounted on the front of the air horn is an idle enrichment device, designed, I think, to give a richer mixture on cold starting and, maybe, at altitude, to compensate for the carb being too lean to start cold without it. One of the things I'm wondering now is what the real difference is in this 9002. Is there something that can be done to make it less lean and more like a pre-76 carb? For instance, is there a difference at the venturis? For instance, a difference in the holes in the venturi tubes? Or, since this car was full of junk, is there junk in the idle enrichment thing? Should the primary jets be drilled out?
Sorry to hear someone else having the same trouble. But it does make me feel a little less crazy and/or incompetent. Maybe some brains working together might be the answer.
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Old 01-30-2010, 02:28 PM
dodger1 dodger1 is offline
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Check out demonsizzler's site here www.thermoquads.com , and the TQ sticky at the top of the main Tech page above. Also I might have more info re: removing the idle compensator gizmo - I gotta find an old tech article first.
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Old 01-31-2010, 09:13 AM
chirorod chirorod is offline
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Dodger1,
There isn't much about the idle enrichment on demonsizzler's site, except to say there is one on some carbs, 75-76 or so. He does say there are 2 air bleed holes forward in the primary air horn, there to lean out for smog. Those can be plugged with epoxy. That should make it a little richer and maybe easier to start cold. I also have a 9209 tq that came off the Dodge rv with the manifold I'm using. The 9209 doesn't have the idle enrichment thing hanging off the front. Being off a truck motor, it has less smog. I had it on the car before I got the 9002. It starts better cold than the 9002 but not great. The 9002 has more power at wot. I have the 9209 apart again and found more clog in the right primary nozzle. I'm pretty sure all the clogs are out of the primary circuits in the 9002, which is on the car now and very hard to start cold.
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Old 01-31-2010, 04:53 PM
dodger1 dodger1 is offline
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Sounds like we have practically the same carb. Mine is a 9278 listed for 1979 truck 360, 49 state and Canada, same as the 9209 (no enrichment) The tech article (from MM, May 98, Steve Dulcich) does show how a simple block-off plate can eliminate the item if necc. I guess it's back to checking the float settings, and other basic stuff. Have you done the metering rod set-up as David mentions? I forgot to tell you that's a pretty easy way to vary the mixture without messing with rod and jet sizes.
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Old 01-31-2010, 06:03 PM
chirorod chirorod is offline
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You know, it's probably something simple. I like to shoot right to the complicated stuff. But I have had both carbs apart. New floats and acc pump in the 9209. I have rebuilt many carbs over the years, qjets, holleys, carters, SU's, Hitachi's, Solex's, dual carb and tri carb set-ups, but this tq is a first and there are some differences. I believe float levels and all the basic settings are right. No vacuum leaks (at least external). Vacuum is 20" or better. Idle very nice with the 9002 when warmed up, ok on fast idle after the first couple of minutes. Idle not bad with the 9209, but I did find more primary circuit clog in the right nozzle. That might improve the idle to close to perfect.
An interesting note is that the idle circuit is a separate tube inside the primary circuit. That makes it harder to clean.
Having 2 carbs with identical primary jets makes me wonder if I should drill out one set and try them on the 9002. I also think there might be clog in the idle enrichment. It's been cold in New England and I haven't wanted to get brave enough to r&r the 9002.
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