j9fd3s

iTrader: (3)

ok, looks like you've covered the basics, at this point i'd rebuild it too

i'm actually out playing with my weber right now

ray green

iTrader: (14)

I sure hope so. I took her apart and she looks pretty clean, even the progression circuits. I don't see what her problem is so far. I'll have another look in the morning.

Jeff20B

iTrader: (13)

This car has the full rat's nest on it, right?

ray green

iTrader: (14)

Mostly, here's the rat's that's left:





All apart and clean, ready to go back together:











Here's the GP Sorensen kit:

ray green

iTrader: (14)

While I'm at it I think I'll redo this spare carb that's been sitting around:







If you'll notice, she's a virgin.

mazdaverx713b

iTrader: (91)

will be looking forward to haering the results. did you see anything in the carb that would cause the issue you are having? accelerator pump diaphram look ok?

ray green

iTrader: (14)

Yes, one of the progression (low speed circuit) was clogged up. Also I discovered that the primary and secondary slow air bleeds on one side of the carb were switched on my last rebuild.

Here lies the virtues of rebuilding Nikki's.

Thanks to Sgt. Fox for posting his carb manual, best book I've read this year:

http://foxed.ca/rx7manual/manuals/ma...01979-1985.pdf

ray green

iTrader: (14)

Here’s the rebuild on Carb Number One:

ray green

iTrader: (14)

Here’s what’s happening to Carb Number 2:

Scott1982

Darn Ray - those look great..... However you screwed up big time!!!! There is one more carb in MY cellar that you did not do yet!

Scott

ray green

iTrader: (14)

Send her on down Scott, I'll take good care of her.

Ray

DivinDriver

iTrader: (15)

Verra nice indeed.

mazdaverx713b

iTrader: (91)

so, hows the car running Ray?

Jeff20B

iTrader: (13)

That carb looks very happy. It will love to run right for you now.

mazdaverx713b

iTrader: (91)

any update?

ray green

iTrader: (14)

Dave, right now I'm stymied and unfortunately not driving the Silver One, but I don't mind commuting in the MP5 these last few days, it has AC which is nice in these Georgia summer dog days.

I've rebuilt four or five Nikki's and every one of them has fired right up on installation, needing just the usual fine tuning to run right.

But not this one, which I was especially careful rebuilding - I actually cross referenced every single jet and air bleed to both the carb manual and with my three or four spare Nikki bodies to be sure everything was in order (after discovering that I had inadvertently switched two of the air bleeds on the last rebuild of this carb, without all that much consequence, I drove it about 50,000 miles without noticing an obvious performance problem).

Instead this rebuild is running so poorly I can't even adjust the mixture or idle speed because without constant pumping on the accelerator it quickly dies (even after it's warmed up). Seems to be the same old problem, only worse - as soon as the throttle plates on the primaries open up it just dies.

But now I know it's not the accelerator pump (working fine), the primary venturi ports (both are squirting) or the progression circuits (I cleaned them, then cleaned them some more, then cleaned them some more, followed by tons of compressed air). In fact I'm having a hard time believing there is anything wrong with the carb and other than those switched air bleeds (which alone were worth the rebuild) my problem is not even the carb.

(Yes, I checked the spark at all four plugs, again, lot's of steady spark)

But it sure does seem to be starving for fuel when you hit the accelerator. And if you coax it up to 3-4000 rpms it will keep running, so once a good venturi vacuum is established it at least will suck enough gas to run (in the driveway).

Which as far as I can tell leaves the fuel pump and rat's nest as my next targets. I'm in the process of testing the fuel pump, although I'm going to have to use my thumb gauge to check the pressure since I don't have a real gauge (probably as accurate as most store bought ones anyway, what's three lbs, about enough to squirt 4 feet?).

Then the volume test (where is that fuel pump cut relay anyway, I need to find it to jump the fuel pump). I hope to get these things done this evening, if the afternoon thunderstorms will let up for just one day. Lately every time I pop the hood the sky opens up and down comes the rain.

Nikki's, you gotta love 'em.

DivinDriver

iTrader: (15)

Ray must have been so happy with the results he still hasn't stopped driving.

ray green

iTrader: (14)

Wish it were true DD. But the day will come.

t_g_farrell

iTrader: (1)

Ray come to the dark side of aftermarket carbs and no rats nest. To the land of
electric fans and easy to source american made ignition parts. The promise of
reliability and cheap repairs.

Its all there Ray if you just follow me ...

j9fd3s

iTrader: (3)

i bought an 83 LE that had similar symptoms, after rebuilding the carb a couple times, i eventually found that the air pump had come apart and the pieces had jammed the ACV in a position where it was just a huge vacuum leak.

big vacuum leak = carb not working.

also note that the ACV leak i had was totally INTERNAL. spraying the engine down with brake cleaner did nothing.

i think the fuel volume test is perfectly fine, the wife gave me a juice container that just so happens to be marked every 100cc (and in non metric too) its 2L too, so you could run 2 tests if you wanted. very handy. of course i didn't mention what i'm using it for, she actually used it for juice or something weird....

good luck!

i still have never rebuilt a carb and actually had it fix a running problem, carb problems are always something else it seems. the exception is like the SU's on my tr3, where the throttle shaft bushings wear out, or old nikki's sometimes just leak from the gaskets

ray green

iTrader: (14)

Tim your words sound like they are coming from the Devil Himself. Are you sure that is you speaking or are you being channeled?

J9 thanks, a big bad vacuum leak sure does sound like the solution to this one, no Nikki could go this bad. I don't have the air pump or AVC valve but there are still some contraptions down in that area (antiafterburner valves and other stuff I don't really understand) that need to be looked at more carefully, along with the fuel pump test (I like the big ole nasty vacuum leak explanation better, however).

I'll check it out this evening, looks like no rain for a change.

Thanks guys (even you Tim)!

Kentetsu

It sounds like you've been very thorough Ray, but is there any chance that the fuel jets got swapped around? Sometimes it can be very hard to tell the difference between starving and flooding...

ray green

iTrader: (14)

I've been very thorough Kent. That's the problem, the more I do, the more mistakes I make.

I wouldn't be surprised if it's something as simple as you say. Iin fact I'm sure it is and I'm going to look like an idiot when I finally figure it out.

But I don't think it's the jets. I checked those three times, even went back and pulled the filler locks off to check the last time.

But just to be sure:

The ones with the big holes go in the secondaries.

The ones with the little tiny holes go in the primaries.

Right?

NEWS FLASH:

Houston, we have a problem.

Routine review of the fuel bowl windows indicates a newly evolved low fuel condition.

Follow up tests on the fuel delivery line indicate a No Go.

Resort to Filter/Pump checklist.

t_g_farrell

iTrader: (1)

Look on the bright side Ray. Once this is all sorted I bet your MPG go back to levels
not seen since the white one.

j9fd3s

iTrader: (3)

good job!

ive learned on the weber (ive never touched the float level in anything else), that the float level makes more difference than the jets!