Should I try to adjust my carb on my own?
10-07-2008, 02:36 PM
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Should I try to adjust my carb on my own?
I have an 87 civic dx with a d15a2 motor. I recently failed smog because the idle was too high (~1.1k rpm). All other numbers passed, though HC was very close to fail at 15 mph (1 ppm off).
I tried adjusting the idle speed myself but I created a vacuum leak or opened up a throttle/passage too much (I played with the idle adjustment screw, throttle stop screw, and another screw similar to the other two). The rpm now doesn't fall below 1.5k. I have a few service manuals (helms, hayes, chilton's) as well as an 85 crx dx parts car with a similar, possibly identical, carburetor. My question is this: should I try to keep adjusting the idle with the carburetor?
I've taken this Civic's head off, before. I've yet to disassemble a carburetor, though. I'm also considering the following:
1. swap carbs with the CRX
2. take it to a mechanic or smog repair shop
3. get a remanufactured carb (this one has at least 30k, possibly 50-60k miles on it)
4. just sell the car (it also doesn't have working ac and I've had trouble getting that to work)
Any suggestions?
I tried adjusting the idle speed myself but I created a vacuum leak or opened up a throttle/passage too much (I played with the idle adjustment screw, throttle stop screw, and another screw similar to the other two). The rpm now doesn't fall below 1.5k. I have a few service manuals (helms, hayes, chilton's) as well as an 85 crx dx parts car with a similar, possibly identical, carburetor. My question is this: should I try to keep adjusting the idle with the carburetor?
I've taken this Civic's head off, before. I've yet to disassemble a carburetor, though. I'm also considering the following:
1. swap carbs with the CRX
2. take it to a mechanic or smog repair shop
3. get a remanufactured carb (this one has at least 30k, possibly 50-60k miles on it)
4. just sell the car (it also doesn't have working ac and I've had trouble getting that to work)
Any suggestions?
10-07-2008, 06:22 PM
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As a follow up, I won't need to fiddle with the carburetor. The throttle stop screw I adjusted has a spring wrapped around it. The spring makes it hard for the screw to loosen when tightened, so I accidentally opened up the throttle and thought that I couldn't back out the screw any further.
The idle, which is in the 650-750 rpm range, surges to 1k rpm every 1-2 seconds, so I'm trying to figure that out now...
The idle, which is in the 650-750 rpm range, surges to 1k rpm every 1-2 seconds, so I'm trying to figure that out now...
02-21-2012, 03:06 PM
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Is the surge vacuum related? I have a 87 civic hb with the 1.3 (i think) and it won't idle less than 1k without dying. JW if anyone even does any work on these cars. I thought there would be a lot more info on this site.
I have done a partial rebuild of the carb because the needle in seat above the float was leaking a small amount of gas and flooding the carb. I replaced the two little o-rings on that and adjusted to float. I think I may have a small leak possibly in one of the vacuum diaphragms that came with the carb rebuild kit.(I sprayed carb cleaner around the hoses to see if the idle would rise, indicating a crack or bad hose, and nothing seems to be leaking) My next step is to replace the rubber diaphragms.
The irregularity of the idle, bounces up to 1.5k, and the fact that it dies at a normal idle speed,.7k, makes me think it must be some kind of leak with the vacuum. Any other suggestions?
Thanks
M
I have done a partial rebuild of the carb because the needle in seat above the float was leaking a small amount of gas and flooding the carb. I replaced the two little o-rings on that and adjusted to float. I think I may have a small leak possibly in one of the vacuum diaphragms that came with the carb rebuild kit.(I sprayed carb cleaner around the hoses to see if the idle would rise, indicating a crack or bad hose, and nothing seems to be leaking) My next step is to replace the rubber diaphragms.
The irregularity of the idle, bounces up to 1.5k, and the fact that it dies at a normal idle speed,.7k, makes me think it must be some kind of leak with the vacuum. Any other suggestions?
Thanks
M