Nikki issue (how surprising)
02-28-09, 09:20 PM
#1
Speeding Dream
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Nikki issue (how surprising)
I have a problem with my Nikki carb, my 4bbl is not opening, so the car has almost no power, and starves for fuel around 5000rpm. I took my carb off this morning, and the venturi's were frozen shut, so I lubricated 'em, and got them working. I thought this was the problem, so I put it back on the car, and test drove it. Still didn't work, checked my vacuum diaphragm again, and it's fine. I'm out of ideas. I think it's a clogged vacuum port. How would I go about cleaning that out? I'm real convinced to just convert to manual secondaries, but don't know about how to do this effectively. My dad's got his Nikki off his '82 right now, and he put some chicken wire around it and made manual secondaries, but that would snap after about 1, maybe 2 uses of the throttle. Would anyone else have any pointers on this? All input is appreciated. I've had my '79 for a little over 2 weeks now, and the 4bbl has been non-operational since I got it. It handles great, it's just SLOW! 
lol, would like to drive it when it's working properly. thanks
lol, would like to drive it when it's working properly. thanks
02-28-09, 11:57 PM
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I was having the same problem. My secondaries weren't opening. I did a temporary wiring and had them running mechanically until I rebuild the carb. But I found out it wasn't the carb or the diaphram. If you still have the vacuum system it's a ground issue. I reground my vacuum system and they work fine.Do some troubleshooting through the engine harness.
03-01-09, 12:49 AM
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Wow, the stupid chicken tie might actually hold up? lol. I want to rebuild the thing, but just have no time. I've been playing around with it since 7:30 this morning, and that's as far as I got. It's all back on now. Could you possibly elaborate more on that grounding issue? I have a little wiring harness connected to the carb that's not connected to anything, could this possibly be the issue?
03-01-09, 01:42 AM
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I just went and pooped around with it some more. I can't, for the life of me, find where this little dangling loner of a wiring harness might go. I went and looked on my '85 parts car, and it's got the same little wiring harness just hanging out there by itself. Is this some stupid diagnostic thing or something? It's got a green, and a black wire leading into it, and the harness looks like a vertical rectangle on top of a horizontal rectangle, with the clip on the bottom. I've been looking for a somewhere where it may go, and I can't find one anywhere
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03-01-09, 09:08 AM
#9
Nikki-Modder Rex-Rodder
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Perhaps THE MOST documented Nikki problem on this whole forum is power loss at 5000-5500 RPM, due to a clogged fuel filter.
I don't know how you know your secondaries are not working. I presume that you don't know that the vacuum secondaries come on only under load. In other words, you'll never get them to come on in the driveway by reving the engine; -Again, very well documented here.
If you had to lubricate the throttle valves just to get them moving, then chances are you have old fuel residue inside the carburetor. This does all sorts of nasty things, from clogging air jets to accumulating in the vaccum secondary circuit and clogging it so that the vaccum box never gets a prompting vacuum signal, which comes from an orifice in the side of the left hand side primary venturi.
The plug you describe is probably for the richer solenoid. Is your car an automatic? In either case, don't worry about that. However, you DO, absolutely have to have the "float bowl ventilation solenoid" hooked up. With the air filter canister removed, this is located front & center on top of the air horn. it has a black 7 white wire hanging out of it, and it needs to be hooked up to the 12V+ ignition switched power. If this is not hooked up, you'll have all sorts of irradic flooding.
Keep in mind that even though you are most likely experiencing a lean condition like you suspect, an over-rich condition to flooding or clogged emulsion tube air bleeds can also cause a low power situation in the high end.
I don't know how you know your secondaries are not working. I presume that you don't know that the vacuum secondaries come on only under load. In other words, you'll never get them to come on in the driveway by reving the engine; -Again, very well documented here.
If you had to lubricate the throttle valves just to get them moving, then chances are you have old fuel residue inside the carburetor. This does all sorts of nasty things, from clogging air jets to accumulating in the vaccum secondary circuit and clogging it so that the vaccum box never gets a prompting vacuum signal, which comes from an orifice in the side of the left hand side primary venturi.
The plug you describe is probably for the richer solenoid. Is your car an automatic? In either case, don't worry about that. However, you DO, absolutely have to have the "float bowl ventilation solenoid" hooked up. With the air filter canister removed, this is located front & center on top of the air horn. it has a black 7 white wire hanging out of it, and it needs to be hooked up to the 12V+ ignition switched power. If this is not hooked up, you'll have all sorts of irradic flooding.
Keep in mind that even though you are most likely experiencing a lean condition like you suspect, an over-rich condition to flooding or clogged emulsion tube air bleeds can also cause a low power situation in the high end.
03-01-09, 08:26 PM
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I have the same problem with my car, no power at all, car was stop or run only 2 or 3 times in last 4 years, first i have high idle about 1100RPM, it was the engine "oil breath" connection that have break, fix it but still no power, but idle is ok now.
the sec are not open, it is like a 60hp car.
By the way, because of the extra air the car get 0 (zero) CO2 in emissions control, the guy think it was not possible in this type of engine.
the sec are not open, it is like a 60hp car.
By the way, because of the extra air the car get 0 (zero) CO2 in emissions control, the guy think it was not possible in this type of engine.
03-01-09, 09:06 PM
#11
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Perhaps THE MOST documented Nikki problem on this whole forum is power loss at 5000-5500 RPM, due to a clogged fuel filter.
I don't know how you know your secondaries are not working. I presume that you don't know that the vacuum secondaries come on only under load. In other words, you'll never get them to come on in the driveway by reving the engine; -Again, very well documented here.
If you had to lubricate the throttle valves just to get them moving, then chances are you have old fuel residue inside the carburetor. This does all sorts of nasty things, from clogging air jets to accumulating in the vaccum secondary circuit and clogging it so that the vaccum box never gets a prompting vacuum signal, which comes from an orifice in the side of the left hand side primary venturi.
The plug you describe is probably for the richer solenoid. Is your car an automatic? In either case, don't worry about that. However, you DO, absolutely have to have the "float bowl ventilation solenoid" hooked up. With the air filter canister removed, this is located front & center on top of the air horn. it has a black 7 white wire hanging out of it, and it needs to be hooked up to the 12V+ ignition switched power. If this is not hooked up, you'll have all sorts of irradic flooding.
Keep in mind that even though you are most likely experiencing a lean condition like you suspect, an over-rich condition to flooding or clogged emulsion tube air bleeds can also cause a low power situation in the high end.
I don't know how you know your secondaries are not working. I presume that you don't know that the vacuum secondaries come on only under load. In other words, you'll never get them to come on in the driveway by reving the engine; -Again, very well documented here.
If you had to lubricate the throttle valves just to get them moving, then chances are you have old fuel residue inside the carburetor. This does all sorts of nasty things, from clogging air jets to accumulating in the vaccum secondary circuit and clogging it so that the vaccum box never gets a prompting vacuum signal, which comes from an orifice in the side of the left hand side primary venturi.
The plug you describe is probably for the richer solenoid. Is your car an automatic? In either case, don't worry about that. However, you DO, absolutely have to have the "float bowl ventilation solenoid" hooked up. With the air filter canister removed, this is located front & center on top of the air horn. it has a black 7 white wire hanging out of it, and it needs to be hooked up to the 12V+ ignition switched power. If this is not hooked up, you'll have all sorts of irradic flooding.
Keep in mind that even though you are most likely experiencing a lean condition like you suspect, an over-rich condition to flooding or clogged emulsion tube air bleeds can also cause a low power situation in the high end.
Anyways, no, I've got a 5-speed. The idle's fine, and the car runs great. However, it is running VERY rich, rich enough to where the car will actually START in cold weather with NO choke at all (my choke cable's busted) lol. My only prob. Is that the secondaries aren't opening at all. I'm pretty sure that the vacuum port is just clogged. Bleh. I'm not going to mess with it anymore, vacuum secondaries suck. I'm just going to wire-tie the thing for manual secondaries and bypass all the bullcrap, and save myself from a big headache..ha
03-02-09, 02:24 AM
#13
Check your teeter totter. SA's tend to run richer than FB's so you will always be a little bit rich. Also make sure you can manually open the secondaries and that they aren't stuck. People only hate vacuum secondaries because they either can't get theirs working properly or just want to mash the gas and have instant power at 2k rpms(which results in bogging since there is no power there anyway)
03-02-09, 10:01 AM
#14
The green connector (choke return solenoid valve) on the wiring harness that leads to the carb is not used on '79's. Only the yellow connector is used (it runs the vacuum solenoid for the anti-afterburn valve).
The green connector is only used on 1980 Federal-spec carburetors, among SA's.
The green connector is only used on 1980 Federal-spec carburetors, among SA's.
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