1987 Brat - Need to fix idle Issue

[aba4430]

Folks,

I put a remanufactured carb from Advance Auto Parts in my Brat and have been trying to get it to work right for about a month now. This is what happens:

1. It starts up fine and runs up to about 2k rpms, so the choke is working, I know.
   
2. After about 5 minutes of routine driving, as the car warms up (and I believe the choke returns to normal), the engine dies as soon as I stop at a light and let off on the gas. If I am slowing down, I just use the clutch to restart it and continue going.
   
3. After about 15 minutes of driving, when the car is fully warm, it stays running, and runs well. Does not die after this point at all.
   
4. However, even after it is warm (item # 3 above), I feel a slight flat spot once I start off from stop. No flat spot once it is running. I only feel it when moving away from a stop.
   
5. One additional item I have noted is that upon cold start-up, during slow take-off, the engine does not appear very smooth - like a fuel starvation issue, so this is another twist to the problem.
   
6. Vacuum connections appear to be fine - checked visually only.
   
7. The fuel filter and vapor separator are brand new. The remanufactured carb is a DCP306-26 (Champion, I believe).

I stopped at Advance yesterday and let them know that I will most likely have it replaced - of course they have no problems and will swap it out for me. However, I want to see if this is something simple and can be worked out without swapping the whole carb. I have searched the list and looked into HTKYSA and have a pointer - check the anti diesel solenoid. I will check this for proper operation tonight. Any other advise is appreciated. If I cannot figure this out, I will get them to order me a replacement.

Regards,

Ashok

[GeneralDisorder]

Sounds like a bad rebuild - might have forgot the plastic check ball on the accelerator pump. That will cause the flat spot you describe. As for the idle, I would say the choke is set too light, and is pulling off to fast. The choke is something you have to adjust for your altitute, and temp conditions, so not neccesarily the job of the rebuilder.

 

For what you paid for that rebuilt Hicrappy (I'm betting), you could get the fuel injection from an EA82..... or a Weber. More power, and easier to work on (in both cases).

 

GD

[aba4430]

GD,

Another thing I noticed is when it is very hot outside (like the past few days), the car wants to die after just a few 100 yards, so might have a point about the choke. I will look into it also.

Appreciate it.

Ashok

[northguy]

You may have some residue (crap) in the throttle body portion where the idle solenoid is located. Sometimes by covering the carb when the motor is at high rpms and quickly pulling the rag off can suck the debris out. If not, it means taking the carb back apart.

[aba4430]

Replaced the Champion unit with a National Carburetor SUB-174 model rebuilt unit yesterday. The carb looked like a brand new quality unit, came with two gaskets. The Champion had came with only one gasket with a botched up and spliced 3 wire harness. The Brat runs way smoother now. I need to dial in the idle speed now and fix the AC idle up adjustment (I need help with this - if someone has detailed instructions on adjusting the AC idle up, please post). On the drive from Petersberg Advance Auto Parts to home via 95, the Brat hit >85 mph with AC on. It feels freer, more responsive now. Used to struggle to get up to 75 previously. Anyway, I believe my Champion rebuild was faulty. Now to fix the AC idle up adjustment.

Regards,

Ashok

 

PS. Link to National Carburetor

http://www.nationalcarburetors.com/cat-subaru.html

[rch10007]

After seeing the prices for those carbs I feel like I got ripped off at my local rebuilder. I must say though - for $300, I have the original carb that came with the car, a complete bench test and adjustment before going back on, and a lifetime warranty on all the parts! Six in one hand, half dozen in the other!!!