Fresh Rebuild, Rebuilt Nikki... Hard to start
 

Well, before I get flamed for not searching, I did. :)

Let me start with a little history. I got two FB's (82 GSL and an 82 non-GSL). The GSL was supposedly running, but has lots of issues.. I rebuilt the carb, tried it again.. same deal... just a stumble start...sounded like a blown rear rotor. Did a compression test on both cars... both cars had blown rear rotors. OH WELL.

So, I rebuilt one of them, new housings, full rebuild... not my first rebuild.. I'm pretty sure I know what I'm doing. :) Compression test on this rebuild looks great 100+ on all faces, all rotors. I'm using my freshly rebuilt carb. I'm using a brand new fuel filter, new plugs, new wires, starter spins fast and strong.. battery is in good shape. I've double checked for vacuum leaks.. can't find any. I've re-stabbed the dizzy like.. 10 times just to make sure.

I did get it started pretty good (albiet with a little vibe/ignition timing issue) when cold. Once it warmed up and the choke came off, the engine spun down and died.. haven't been able to start it since.

Its getting plenty of fuel, and I've tried un-flooding it with oil in the chambers... doesn't seem to change anything.

I really want to know how to set ALL of the carb settings back to a neutral/default/OEM/stock position.. Like... screw the mixture one in all the way, then back it off 5 full turns... or something.

The plunger nearest the water-pump has what looks like a TPS adjustment (I'm an EFI guy), how do I adjust that back to default as well?

I've looked for how to adjust a carb, but all of the how-tos I've found say "Step 1.. Warm the car up". Doesn't really help me. :)

Any help is appreciated. sorry if I left anything out, I'll try and fill in the gaps as the questions/replies start flooding in.

--Micah

EDIT: I *HATE* carburetors... :) So, be descriptive.. and patient.... :)

I believe the bench setting for the mixture is to screw it in all the way, then back it 3 1/2 turns out, but don't quote me. Check ignition.. I had this problem once... put it away, then I tried it again and it didn't want to start. Figured out the leading plug wires were reversed. Still don't know how that happened...

The only thing on the ignition I don't quite understand is which coil goes where? The L and T on the dizzy... which coil do those go to? I didn't think they would matter since the timing of the spart is determined by the dizzy itself and not the coil.. so as long as the coils were charged, it wouldn't matter... I've tried swapping them though to no avail.

The T goes to the one closer to the front of the car.

the only suggestion i could give u is to double check everything...if u think the engine is ok then i would check fuel pressure(stock should be like 4.5 maybe?) then check spark....idle adjustment....air....vacuum leaks....idle mixture....accelerator pump adjustment....just some ideas

The loneliest feeling in the world is getting your newly rebuilt engine in and then trying to start it, and it doesn't go. I've never rebuilt a rotary (yet) but every piston engine I rebuilt had to be towed to get it started. Something about that first run-in.

Fuel pressure is fine, I actually swapped in an aftermarket elec universal one (5psi) just to be sure I was getting enough.. back to stock now.

I just did it again while I was waiting for responses... while cold it runs fine as far as I can tell... the INSTANT it warms up and the t-stat opens, it dies..

What systems are coolant-temp operated?

If you flooded it, you've done 2 things, fouled/wetted the plugs and washed the all the lubrication out of the housings needed for combustion sealing. Clean and dry the plugs, pour a capfull of motor oil down each barrel of the carb. Crank the engine over with the fuel shut off to spread the oil around, then re-install plugs and start it.

If it still fails to start, go back and set the engine to TDC per the 'How To' in the archives and check the timing pulley and timing. Other possibility is the needles are not yet worn in enough to seat fully, flooding the engine.

You posted again while I was typing this, oh well.

When the choke pulls off, how does it seem to dying, like it's running out of fuel, rpms slowly drop, sputters to a stop? Turn the mix screw 3 full tuns out, then you might need to crank up the idle screw for a while to raise the idle while the seals begin bedding in.

Good info, let me go over some updates:

* It starts consistently now when cold.. but dies when it gets hot.
* When it dies, it just slows to a stop. Over maybe 4-10 seconds. Doesn't act like its running out of fuel, just sounds like its lowering its idle.
* I have checked TDC and the dizzy's position as well as the pully marks. All are well with the world (I marked them when they came off)
* One thing I noticed that isn't hooked up is the idle compensator on the air-filter thing.. There doesn't appear to be anywhere to hook it up on the vacuum spider, but according to the FSM, there is a vacuum block-off-nipple on where it WOULD hook up. It wasn't hooked up before either.
* I've set the mixture to 3.5 turns out as per the previous post. but I'll put it in 1/2 turn. Ignition is getting spark to all of the plugs.. None of them are crazy fouled. I've cleaned them all off, dried them with compressed air, and re-installed more times than I care to admit.


How many turns out should the idle SPEED adjustment be? anybody have a good baseline for that? Which way makes it go faster, which way makes it go slower? I'm sure this is in the FAQ, so after posting this I"ll go check.. but.. yeah.

Thanks for the help, I feel ultimately retarded with carburetors. :)

Download the carb manual. It's linked around here somewhere..

Update: I hate this thing...

It starts when it wants to, runs when it wants to... and doesn't... when it wants to. I realize that sounds stupid... If somebody said that in the 2nd gen forum I'd think "nawww, SOMETHING has to be happening to cause it".. but...

After I posted that, I let it sit so the battery could charge.. This time, I went out, tried to start it now that it was cold.. wouldn't start.. choke, no choke, gas manipulation, no gas... wouldn't matter... cranked it for about 10 minutes... went in the house frustrated.. came back out 5 min later... same thing.... went in the house frustrated again.... came back out 5 min later... started up with no hesitation and held an idle at about 3500rpms. So, I thought "Oh great.. now its just going to die once it warms up"... So I let it.. it warmed up.. and kept running at the same idle! I let it run for about 5-10min (don't recall), then turned it off to re-check fluids and what not. Tried to re-start it.. nothing.. just cranking incessantly. Left it for 5-min or so... came back.. same thing.. left it for 5 min... came back.. started right up... but idled for a couple seconds solidly... then just died. Haven't been able to start it since..

I'm to the point where I don't know why I ever bought something with a carburetor on it. :)

Help? What should I try now.. I'm frustrated... so things that should be obvious, aren't...

Also.. Would stripping off the rats nest be a good or bad thing in this case? I would imagine it would simplify this whole process and make things easier to troubleshoot. I'm really tempted.

I might be up that way in about a week or so, I could take a look at it for you then if you are still having trouble with it. I've had my hands on a few of those Nikki's.

I would appreciate it actually... but until then, it would be nice to not be renting a rental to get to work and back...

--Micah

Plug the hose for the idle compensator that goes to the air cleaner, it's a big vacuum leak when open. To raise the idle, turn the throttle screw in and try to keep the idle around 2k if you're going to leave the engine running for break in while sitting.

Removing the rats nest will clean up the engine and eliminate potential vac leaks. Your choice.

You mean plug it on the vacuum spider side right? I actually have no exposed hose/vacuum spider location for it to plug into... just open on the blue intake housing.. That shouldn't matter as its still metered air. Correct?

--Micah

long shot have you checked the float bowels is the fuel level at the screws on both side's only problem iv had with nikkis is the damn neeedles seating

just a thought.

yes i would recomend it helps alot plenty of info on the board on how to do it...

makes it alot easeyer to find vaccum leaks.

Well, I set the float level with the little measuring thing that came with the rebuild kit... and it shows in the sight-glasses about half-way... sometimes a little more, sometimes a little less... Depends on vehicle orientation.. Its on mostly level ground right now and its almost exactly half way... atleast on the front one.. can't really see the back one.

But they ARE new float valves... so perhaps they just need to seat properly. Dunno. All I know is that if I can't get it running today, I'm either going to A. give the car to my dad, let him figure it out.. B. Pull all of my hair out. C. Start beating my wife. D. Cry incessantly while sucking my thumb and rocking back and forth in the fetal position.

none of your options are a option :)

i guess if you have all the emissions on the carn it will be hard to see the rear but you do need to know if both are equel and if the fuel level dose drop under operation it still might need some adjusting they can be very fidley and anoying trust me i spent a few days on and off with the carb and eventually i got it right..

never heard of any messuring thing but there are messurement the floats need to be at which should be on the rebuilt sheet.. be carefull when adjusting the tabs.

do some searching plenty of info on the subject..
putting some motor oil on the ends of the needles can help them seat. there has to be 100% no particals on the needle seats.

hope it helps

Yeah, I was meticulously clean with the carb rebuild.. did it on my kitchen counter because my shop is sorta dirty from a painting project I'm also doing.

I also used oil on the needles as the rebuild instructions said.. used 2-stroke.. not that it really matters. I am going to go shopping for the emissions removal/vacuum crap removal stuff in a bit.. I'll be leaving my air-pump on for now though... just so I don't have to mess with belts. Anyways.. thanks for the replies, I'm still not convinced that removing emissions is going to fix this.. but, why not. Its just money and time.....

I vote for option D, it's easier to get over and less permanent, lol. The idle compensator tube that goes to the bottom of the air cleaner needs to be connected to it or plugged.

Take a break from it, read the rats nest removal and decide if that's the way you want to go. In the mean time, check all of the vac lines for leaks and correct routing. If nothing else, start plugging them. A 3500 rpm idle is a huge leak or poorly adjusted idle speed.

i didnt see any where but do you have a fuel pressure regulator the stock pressure is between 2psi-2.5psi 3 is pushing it

Hmmm.

The toughest thing is the idle mixture, and like you said, it's not like you can warm it up.
So first, bypass the idle circuit by adjusting the idle speed so high that the carb is actually not running on the idle circuit. This way the idle mixture can be screwed up (no pun intended) but it won't matter. If the idle comp valve system is leaking, that won't matter, either.
Just turn the idle speed screw in a few turns so that when you look down the primaries, the valves are visibly open about 1 mm. IFIRC, the idle speed screw on the 82 Nikki is a bit tougher to get at than the latter ones. The later Nikkis used a screw with an elongated head so you could reach the damned thing, but if memory serves me right, the 82s have the short version. Either way, it's located on the firewall side of the carb, on the front (primary end) down at the cast iron throttle body, under all the linkage. It's a BIG pain in the ass. But you need to get yourself familiar with it. REAL familiar with it, because you're going to want to screw it out fast to lower the idle on that newly rebuilt engine. A long flat-blade is what you'll need, and possibly an 8mm wrench if there's a locking nut behind it.

This will at least get you to where the engine should start on the main circuit.
There are other hazards;

Make sure your float bowl solenoid is hooked up. If it's not, the fuel won't be able to come up through the emulsion tubes easily. If it does, it will begin to siphon out and flood the carburetor. The float bowl vent solenoid has a single black and white wire coming from it. It's located front, center, and top, in the air horn. This needs to be hooked up to an ignition-switched 12v POSITIVE lead. BE CAREFUL, DAMNIT!
If you make a cute little spark next to the flooded carb spewing fuel vapors, you could be in for a surprise. 1 in a million chance, I know, but a burned face isn't worth it.

Make sure your accelerator pump is working correctly. You should see two good squirts going into the primaries when you operate the linkage by hand. If you don't, then something's messed up. But before you flip out, check to see if the float bowl behind the accelerator pump has fuel in it. If you've been playing with it without the fuel pump going constantly (it only kicks on for a few seconds at first ignition switching) you'll squirt out all the fuel in about 8 or 10 pedal pushes.

Don't worry about that throttle position sensor you mentioned.
No more oil down the carb, and no ether.

Its good to see you back Sterling. Always great info!