Misthael

Okay. So I put the puley on every way it would go on and I got her started, idles pretty solid, and drives fine. THe sputtering is even a little better. But when I use the timing light I don't get anything from the leading plug wires. It doesn't make the light turn on. WTF? I thought I was supposed to time it using the L1 plug wire? Instead I used the T1 wire and the leading timing mark lined up with the pin. And when I rev hte engine the timing marks move further away from the pin. I don't gt it. What's goin on? Are my leading plugs not firing? Cause if they are I should be getting the timing light to work on the L1 wire right?

cdrad51

If the timing light doesn't light up with either leading cable, your leading ignition is down, which is good news because you'll see a big difference when you get that one working again.

Test ignitor and coil and determine which one is not working. Replace. Check timing again as I suspect you are way too advanced.

gsl-se addict

iTrader: (3)

Yes, you are suppose to time of L1. If your leading is not firing, that would expain the sputtering. Take the leading coil wire off of the dizzy and put it next to the chassis and crank the engine (you probably want to remove the trailing also so the engine doesn't start). If you don't see spark jumping for the wire to the chassis, then the leading is not firing.

if this is the case:

-Check voltage to the leading coil (both + and - terminals should have ~12v with the key in the on position, engine not running)

- Check to plug to the leading igniter (black box on the front of the dizzy). Sometimes it looks like the plug is plugged in, but it is not in reality.

- If those are both okay, try switching positions of the igniters. This way the leading should have spark but the trailing won't. The trailing isn't very important and the car will run well without it. The only thing is that if you have an '84-'85, the ECU gets its signal from the trailing coil to activate the fuel pump. If your car is one of these years, search for 'fuel pump relay bypass'.

Hope this helps.

Kent

Misthael

How exactly do you check the igniters? The Haynes manual says to use a switch and a 10A light bulb and do some funky wiring ****. I don't wanna do that. I guess I could just go find a 7 at a salvage and rip off an igniter. The igniters are $175 a piece from the local import parts store here.

Misthael

I switched the igniters which made both of them work. I used the test light and the timing is dead on when idling. I have her idling at 1500rpm. Is that too high? It's real rough at 1000rpm. The sputtering only happens under load at 1/4 throttle. I'm thinking that's a break in issue or the mixture at 1/4 throttle is bad. The higher the rpms the farther away from the pin the marks get. Is that advancing or retarding and should it be doing htat? I have the vaccuum tubes plugged. Could all this be fixed by a locked distributor and a dual leading igniter direct fire ignition system? (DLIDFIS)

gsl-se addict

iTrader: (3)

Good to hear that you got it working. Usually, you will want to uncap (leave open to atmosphere) the vacuum advaance diaphrams if you don't want to use vac advance. Many people running like this will set the timing at full mechanical advace (about 4000 engine rpm). I don't remember the actual numbers offhand, but you could find them by searching, I bet.

The timing in this case can be either done with a timing light that has adjustable advance (some people don't have luck with these) or you can mark the pulley for your new lines. The pulley is 360mm in circumference, so 1mm=1 degree. Just mark off from the leading mark to where you want the engine to be at full advance and make a mark there. That is were you will want to set timing (above 4000 rpm).

For the idle, 1500 rpm will be fine. Usually, rebuilds will not like to idle down low until they get broken in some. As you run it more, the engine will start easier and run smoother. You will be able to drop your idle then.

Hope this helps some.

Kent

cdrad51

So what hapenned after you fixed that vacuum leak?

Kentetsu

As stated before, it sounds like your leading ignition has taken a dump on you. To find out quickly, you could switch the ignitors and the coils around. That should leave you with no trailing ignition, but you will at that point have leading working.

Next, you're going to have to return your timing to where it should be. Right now it's firing late, so that the trailing is firing in place of the leading.

Also, you're going to have to find a way to get the idle down before you can properly set the timing with a light. At 1500 RPMs your mechanical advance has already started to come into play. Get your idle down, even if its running rough when you do. Then when you get the timing right it may fix your idling issues as well.

Good luck with it man...

Misthael

Here's the latest. I switched the igniters and now both are working. I set the timing right on the marks. I got the correct fitting for the brake booster vacuum line so there's no vacuum leak. It still sputters when I hold around 3k rpms just sitting in neutral or when I hold a speed where the rpms are higher than 2k. So I figured it was the float level. I adjusted the screw without taking the carb apart and I think I just made it worse. The Mikuni manual I purchased is not very clear and I'm not sure I set the float level correctly. If the float level is off it could cause a lack of fuel in higher rpms right? That's what I think is happening. What are your opinions on this? And if you know of any detailed guides for setting the float level on a Mikkuni 44PHH a link would be greatly appreciated.

Misthael

Here's the latest. I switched the igniters and now both are working. I set the timing right on the marks. I got the correct fitting for the brake booster vacuum line so there's no vacuum leak. It still sputters when I hold around 3k rpms just sitting in neutral or when I hold a speed where the rpms are higher than 2k. So I figured it was the float level. I adjusted the screw without taking the carb apart and I think I just made it worse. The Mikuni manual I purchased is not very clear and I'm not sure I set the float level correctly. If the float level is off it could cause a lack of fuel in higher rpms right? That's what I think is happening. What are your opinions on this? And if you know of any detailed guides for setting the float level on a Mikkuni 44PHH a link would be greatly appreciated.

Misthael

Here's the latest. I switched the igniters and now both are working. I set the timing right on the marks. I got the correct fitting for the brake booster vacuum line so there's no vacuum leak. It still sputters when I hold around 3k rpms just sitting in neutral or when I hold a speed where the rpms are higher than 2k. So I figured it was the float level. I adjusted the screw without taking the carb apart and I think I just made it worse. The Mikuni manual I purchased is not very clear and I'm not sure I set the float level correctly. If the float level is off it could cause a lack of fuel in higher rpms right? That's what I think is happening. What are your opinions on this? And if you know of any detailed guides for setting the float level on a Mikkuni 44PHH a link would be greatly appreciated.

Misthael

Here's the latest. I switched the igniters and now both are working. I set the timing right on the marks. I got the correct fitting for the brake booster vacuum line so there's no vacuum leak. It still sputters when I hold around 3k rpms just sitting in neutral or when I hold a speed where the rpms are higher than 2k. So I figured it was the float level. I adjusted the screw without taking the carb apart and I think I just made it worse. The Mikuni manual I purchased is not very clear and I'm not sure I set the float level correctly. If the float level is off it could cause a lack of fuel in higher rpms right? That's what I think is happening. What are your opinions on this? And if you know of any detailed guides for setting the float level on a Mikkuni 44PHH a link would be greatly appreciated.

Misthael

Wow. Each of those 4 I got an error and when I refreshed the site it hadn't posted. Now that I close out everything and come back it posts 4 times. Great. Somebody delete the last 3 plz.

Kentetsu

Congrats on getting the timing straightened out. I don't know much about Mikuni's though, but I'm sure someone here does.

That miss at 3k could still be a spark issue. Plug wires, plugs, cap/rotor, weak coil, bad ground, etc.

I would suggest putting the float back where it was, then making sure the ignition is straight before looking at the carb.

kenn_chan

Misthael,

Dude, you are going to have to learn to merss with one thing at a time! get your timing fixed then play with the carb or whatever!
all you are going to end up doing is confusing yourself because you have entered so many variables into the equation. one thing at a time.

kenn

Misthael

I have new coils, new plugs, new cap, new rotor, and everything ignition is working like it should. The timing is fine. The vacuum leak is fixed so it will idle at 1100 fine. I am doing one thing at a time. The only thing left is the sputter. I went through the Mikuni manual again and it could possibly the pilot jets are a little small. I'd really like rx7doctor's opinion since he's the one that told me what size jets to get.

cdrad51

It could be the jets are too big. Running too rich will also cause sputtering - don't ask me how I know. Pull your plugs. Are they black? brownish? whitish? that'll give you an idea of you rich or lean you're running.

Tom

Is it 'stumbling' at steady cruise around 3-3.5K RPM? Does it go away at higher rev's?

Misthael

It goes away whenever I go to a gear higher to reduce the revs to approx. 2k, but I can't go over 4k because I'm breaking her in so I don't know about high revs. I assume it would go away. If it's sputtering and I give it gas it will accelerate with no problem. No sputtering. Smooth acceleration. It's only when I hold revs around 3k. I just went out and held the throttle open to approx. 3k rpm and watched the fuel pressure guage. It dropped ever so slightly. I have the pressure set at 4.5 and it didn't drop below 4.4. Is that a problem? Also when I let off the throttle after holding it at 3k until it bogs, it idles rough like there's not enough fuel and it slowly smooths out like the fuel level is catching up.

cdrad51

plugs color? a pic would be ideal.

Tom

If you are driving the car and trying to hold at cruise and it 'stumbles'- it happens to a lot of 2bbl carb owners.

I tried a Weber 45dcoe a year or so ago and switched back to a stock carb because it was so annoying. I do more cruising than WOT bursts. No reasonable combination of jet change or fuel pressure change fixed mine. There was an interesting reply by Bill Shurvington as to the culprit and he offered a homespun remedy. I'll see if I can dig up the thread.

(BTW- my 1st RX7 had the same Mikuni carb.. It stumbled a wee bit at cruise too)

Tom

Here it tis: https://www.rx7club.com/showthread.p...t=weber+tuners

Misthael

Here's a pic of the spark plugs from my front rotor housing:


Pretty black.

Rogue_Wulff

A tad rich. Bet it smells rather strong from the exhaust.
If the exhaust is not overly obnoxious, this could be a result of flooding previously.

Misthael

I figured it was rich, but would that make it sputter?