carb issues (I think)!

[chykov's76doba]

Ok, the saga continues...I switched out the lean burn in my 76 Cordoba (400, 44bbl). At the same time I put in a new non lean burn tq (9036s) out of a 75 440 truck. It worked ok, though I was getting hesitation when I accelerated. So I took the carb out, cleaned her up, New kit, brass floats etc... Now she starts and idles beautifully, but when I put her in gear, she stalls. Any thoughts?

 

[slepr1]

Thermoquads don't like allot of fuel pressure. Are you running a stock fuel pump? TQs only like around 4-5 psi. If you have any higher fuel pressure you need a fuel regulator to dial it down. High volume fuel pumps generally run 7 psi. Fuel regulators are cheap costing under $50 and mount after the fuel pump and are adjustable.

 

[chykov's76doba]

Thermoquads don't like allot of fuel pressure. Are you running a stock fuel pump? TQs only like around 4-5 psi. If you have any higher fuel pressure you need a fuel regulator to dial it down. High volume fuel pumps generally run 7 psi. Fuel regulators are cheap costing under $50 and mount after the fuel pump and are adjustable.

Yes, the fuel pump is stock. Only things I've changed are the ignition/distributor and carb.

 

[Billschroeder5842]

While it could be pressure, have you given the car a basic tune up?

If my car ran okay but stalled, I'd adjust the richnest on the carb, advance the timing a bit and bump the idle.

Sounds just like a tuning issue to me.

Are you pulling 17-20ish vacuum??

I have a 400 4bbl, Idle at 800, vacuum at 18 and timing at 10 btc.

 

[chykov's76doba]

Yes, new plugs, wires, etc... I had the timing at 10 btdc and the idle was at 750rpms. I will check the vacuum, and adjust the carb. Thanks. I will keep you posted.

 

[rumblefish360]

Adjust your initial timing as much as you can get away with. Then limit the mechanical to approx. 36*'s. (This can vary a little bit) limit full advance , vacuum hooked up to IIRC 60*'s

I think I need to check the MoPar engine book again for that, but that is where you'll find the info.

Recheck your pumps shot. Moving the rod closer to the carb body gives you more shot. More is t always better ether.

The older carb maybe running out of wack because it is an earlier carb with more than likely different jetting. Swapping out the old carb jets into the new carb may not be the solving item ether. Just take your time and tune it. The ignition and carb.

 

[gdennis400]

Are you still running the stock air cleaner with the rest of the emission controls? Your carb. maybe just fine. If so, disconnect the fat hose on the bottom of air cleaner stuff a rag in there, reconnect the hose and run it. If it runs better then the exhaust diverter valve has gone bad and needs replaced. Had the same issue on my 77 Cordoba 360. (Pumping exhaust into the air cleaner.)
Let me know if this helps.

 

[chykov's76doba]

Are you still running the stock air cleaner with the rest of the emission controls? Your carb. maybe just fine. If so, disconnect the fat hose on the bottom of air cleaner stuff a rag in there, reconnect the hose and run it. If it runs better then the exhaust diverter valve has gone bad and needs replaced. Had the same issue on my 77 Cordoba 360. (Pumping exhaust into the air cleaner.)
Let me know if this helps.[/QUOTE

Yes, I am using the stock air cleaner. However, since this was lean burn, there are no other emission controls. Also, I am having the problem with the air cleaner off of the engine.

Do you think my floats could be out of adjustment? Do brass floats need to be adjusted higher than the nitrophyl type?

 

[Billschroeder5842]

Before I would adjust the float, try to set your timing. Mechanical timing could be off, but the vacuum never lies. 17-20 should do the trick. Bump the idle to 900.

 

[gdennis400]

My 400ci was a lean burn (ELB) that was converted to Mopar Ele. ignition. It did not change the Diverter valve. It screws into the hard line coming off the rear of Pass. side exhaust manifold. It is supposed to let filtered fresh air into the exhaust to reduce emissions. When the valve goes bad it allows exhaust into air cleaner. My 360 Cordoba was parked for many years because the previous owner thought the carb. was bad, then did a terrible job rebuilding the carb. I guess he didn't realize WHERE those extra parts went??? I had one hell of a time trying to figure this out.

 

[monaco66coupe]

I have a 77' 400 Cordoba with the same TQ issues. I saw where Jegs sells the Holley spread bore that is a direct bolt up, do you think that would be a good alternative? I had that carb on a 85' one ton maxivan back in 89', and it ran beautifully. Any thoughts?

 

[sleepar]

The pump gas has alcohol and needs a 2size from stock bigger jet... I would tune the carb you have... if it runs make it run better.... then back and forth till it gets worse then go back a notch...

 

[rumblefish360]

I hated that Holley.

Just keep on the TQ before you throw good money away on another carb.

 

[chykov's76doba]

Took the carb off, put another kit in it. Adjusted the floats a little higher. Runs like a charm now! no hesitation, no stalling!:headbang: I need to adjust the idle a bit, but other than that it's running smooth!

Thanks for all your help!

 

[slepr1]

Great to hear! Another success story. When I got my TQ rebuilt, the old timer told me that he loves the TQ but they are a tricky carb to rebuild.

 

[rumblefish360]

Great to hear! Another success story. When I got my TQ rebuilt, the old timer told me that he loves the TQ but they are a tricky carb to rebuild.

Ditto and X's 2 on the above. When you get a good TQ and get it all set up and dialed in right, great carb. For a stock part, they really rock.

 

[1778ppr]

Thanks for posting this. I am planning on doing the same thing you just did to my ’76 Sport Fury 400 Lean Burn (Shake n Bake) system. I have an older TQ I want to rebuild and want to put the brass floats in it. You said you raised the float. What was the final float setting you used? Who did you buy your brass floats from?

You also said you needed to adjust the idle. How’s she running now? Please keep us posted.