gutless wonder

[blackwolf]

hey people hope someone here can help. I have a 84 720 kc with the z24 and it is just down right gutless as of late wont run over 70 and wont run over 50 with a 30mph head wind just replaced the head gasket thought that was the problem but didnt solve anything really rebuilt the factory carb replaced cap rotor plugs fixing to change wires it acts like it randomly misfires even when i just rev it up to 1600 rpms it stutters or misfires not really sure which any help would be great cus i am just lost here

[banzai510(hainz)]

YOu dont think you misalighned the chain ? Cam timming? dist spindal. YOu put timming light on there?

 

rocker arm lash

 

since this is a twin plug type set up you got before after wires correct?

[smoke]

You have checked the timing I assume? How about a plugged cat?

[Kirden]

It's amazing what you find on google:

 

[smoke]

hahaha, nice.

[ggzilla]

One way to solve a problem is start replacing stuff. You might end up replacing the truck but sooner or later it will solve the problem.

[Kirden]

It was a phrase I just had to see, then I busted out laughing in the front office at work...

 

As these guys said, check timing. Also, check the fuel filter.

[ggzilla]

You can test all those parts, but its easier to just replace them. For example the time it takes to measure flow of the fuel filter its faster just to replace it.

[datzenmike]

The rotor has two contacts and there are intake and exhaust side plugs. A good cap will have the terminals labeled. 1I and 1E for example. Both plugs fire together but from two different coils.

 

It's imperative that you check each wire goes to the proper plug. If one is wrong then there are really two wrong.

 

Make sure both coils are working by holding the high tension lead near a ground and cranking the motor.

 

If this is now good, have the timing and the valve lash set. Valve lash is 0.013" for both and way easier to do on a Z series than an L.

[blackwolf]

i was wondering about it being a tooth off too but it idles fine without vacuum at 3 or 4 degrees like the tag says on the hood, valves are set did that about a month prior to the head gasket not sure on the wires gonna double check them....im going to school so replacing stuff is a little out of my price range

[datzenmike]

Replacing stuff is out of the price range of most Datsun owners.

 

Check wires and be sure to check that both coils spark... important and doesn't cost a buck to fix.

[blackwolf]

update for ya'll timing chain is dead on wires all in the right order seem i forgot to push the brake booster line on completely so that fixed my idle issue purrs like its new but still gutless, from what i can tell my secondary is not opening at all unless i red line it then it just cracks a hair it use to open at 2200-2800ish rpm (depending on my lead footedness) when accelerating and closed once my speed leveled off and since at 70mph it only turns 3000 rpms worked great, my new question is which vacuum tube should i hook to for my vacuum advance if i just run it straight with out the thermal valves??? gonna try and weed out cracked lines also

[banzai510(hainz)]

most vaccum adv comes from the carb.

[blackwolf]

yea i know just wasnt sure if it mattered which port i used my book said one or 2 was venture vacuum and the others was something else

[ggzilla]

It matters if the vacuum advance module is leaking. As a test, disconnect the hose at the distributor and block it. Then test drive.

[banzai510(hainz)]

well if it runs worst you know it was wrong. I seen people hook it up to the intake manifold port and that is WRONG!!!!!!! Causes to much advsance and you lkoose poer/ping ect. Sometimes better not to use it if you dont hook it up to the correct spot.

The carb far as I know but Im not a expert on the newer emmission full carbed later nissans

[blackwolf]

so quick update im running the distributor straight off the carb bypassed all the valves and smog bs disconnected the smog vacuum lines still gutless even my mileage has dropped to a record low for the truck 18 mpg was getting 23 not a good thing running 65 miles a day min. have discovered that i seem to be getting fuel in a vacuum tube on the top passenger section of the carb (red outline) so i think the carb is done for anyone have any ideas why there is fuel there??

[ggzilla]

Fuel level may be too high. Where do you see it in the sight glass?

[blackwolf]

dead center of the dot never has been higher since ive had it

[smoke]

Gas in the vac advance line I have seen happen from an engine flooding out really bad, the excess fuel gets pulled in by the diaphragm when the engine dies or gets shut off, but that does not sound like what is going on with you.

[ggzilla]

After putting in rebuild kits, carbs often run worse. Take it back apart and reassemble it. Maybe a check ball is missing or a part inside is loose.

[blackwolf]

smoke....its not the vacuum advance line its lines for the altitude sensor that mine has never had.....ggzilla.. the fuel in the line was there prior to the rebuild part of the reason i rebuilt it thought it had a blow gasket in the carb now im wonderin if the carb is cracked somewhere and i just dont see it...i disconnected all vacuum except the vacuum advance on the dizy and the booster used 1 gal less of gas than it normally did but that still aint right tryin to find cheap weber to test the crack carb theory but not many near me

[ggzilla]

Never seen a cracked carb. But the top can warp enough to leak the power valve signal which will cause rich running. You can see if the top is warped by eyeballing it after removal.

[Robert]

 

It's amazing what you find on google:

 

 

 

OMFG....I vote for you as Pres!!!!

[Robert]

 

i was wondering about it being a tooth off too but it idles fine without vacuum at 3 or 4 degrees like the tag says on the hood, valves are set did that about a month prior to the head gasket not sure on the wires gonna double check them....im going to school so replacing stuff is a little out of my price range

 

 

I guarrantee it will idle fine being off a tooth depending on wether your one tooth advanced or 1 toothe retarded.....it will have crappy power up top and get crappy gas mileage and sputter. If your saying it ran fine but lately it has lost power, then I would look into fuel supply.

 

 

Pull off the valve cover, put at TDC, and make sure the dowel pin is in #2 hole and that the pin is in complete vertical position. You can no longer use the painted chain marks anymore since you have ran it....but you can eye wether you off a little. Also you can pull the cap while your at TDC and see if the rotor points straight to plug 1. A tell tale sign your off a tooth is if your distributor needs to be clocked almost to the end of the adjuster to get timing correct.