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Index > @ the Pickup Bed (General Topics) > Thread: Ignitor died in B2000 (rotary)
Thread: Ignitor died in B2000 (rotary)
Jeff20B


Moderator
Posts: 661
posted August 31, 2003 12:34 AM

Ignitor died in B2000 (rotary)

Yep, I was driving Tom's rotary powered B2000, pictured on my webpage, when the Leading ignitor died. It was an interesting experience to say the least. Long story short, a known good ignitor saved the day, but not before we had to use my REPU to move some stuff that was supposed to be moved with the B2000. My REPU has a nail in the right rear tire, a radiator leak that gets worse each time you run the engine, and a broken oil cooler mount which can only be hard on the aluminum (it's resting on the lower valance sheet metal).

If only we had known it was a bad ignitor in the first place, it would have saved lots of headaches. The reason why it took so long to figure it out was because of the shoddy wiring job.

Whoever wired this truck ought to go back to school. Wanna know how cheesy it is? It seems that both coils share a common key (ignition) switch wire (so what you say? Yes they are supposed to be like that. Just read on, it gets better) with an electric cooling fan, so there's a voltage drop right there. There's no relay to take the load off, so I'm sure the ignition switch wires get plenty hot up near the key cylinder and stuff. Also, when you shut off the ignition, it stays running for a second or two (due to the stored energy in the fan; my REPU does this when the heater fan is on high, but at least my ignition stuff has a relay hooked to the starter solenoid with no other loads on that line). And while we're at it, I discovered something so shocking, that it shook me to the very core of my being; the negative sides of both coils were hooked together! That means no LT split! Do you know how serious this is and why you should never ever do this? Not only do both coils fire at the same time, they also put a serious strain on the Leading ignitor (which is probably what killed it), and what's more, the Trailing ignitor must have been dead this whole time! Holy crap! Not to mention all the electrical tape bulges which no-doubt cover finger twist jobs (or possibly butt connectors, but I doubt it) which add up to increased resistance here and there, and the lack of any corrugated plastic split-loom type wire wraps, zip ties, or any other anti-chafing what-nots. No wonder this truck never ran all that well. The tach is hooked to only one of the coils (can't remember which one), but with them both hooked together, it doesn't really matter. As you can see from the pictures, it's got an RB Holley carb. Running 0 split with a carb is bad news (according to Evil Aviator on the club forum). Also, the spark plug wires look like they've been near a rat's nest, but that's on the high-tension side, so I'll let it slide... for now.

Well, Tom wants me, the DLIDFIS dude, to rewire it. :) I'm going to use GM HEI ignitors on Leading because they're cheap and plentiful, and one more stock FB coil, like the two that are already there. Very very cheap to hook up, and the difference ought to be phenominal, even with a possible dead Trailing ignitor. I'll get into it a little later like maybe Tuesday to see what's up (and when it's actually light outside; we had to swap the ignitor in the dark with only a dim test light to see by), but for now, I just thought I'd share.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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Jeff20B


Moderator
Posts: 661
posted September 04, 2003 10:07 PM

I'm going to start installing some GM HEI ignitors tomorrow.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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Jeff20B


Moderator
Posts: 661
posted September 06, 2003 11:41 PM
Edited By: Jeff20B on 6 Sep 2003 23:57

The only thing I've been able to do on the B2000 on Friday was to remove the old mangled wire mess. I picked up an extra coil today. I may start rewiring the ignition tomorrow or Monday now that I finally have all the parts. Oh, I even came up with a spare coil holder that will work since I misplaced my box of coil holders. I still can't find it. Oh well, this one I have now will work.

Oh also, I discovered beyond a shadow of a doubt that both coils were running off the Trailing ignitor only. I figured it out by rotating the engine to the first timing mark and noticing the T pickup was aligned with one of the reluctor tips. Note that this is supposed to occur with the L pickup, witht he T pickup a few degrees behind. Yep, just as you guessed it; the dizzy was cranked clockwise almost to the end of the curved adjustment slot down on the front cover.

This means that since we replaced the Leading ignitor to get the truck over to my place, it's been running advanced by like 15 or 20 (whatever the L T split is set on this dizzy) for the last couple miles.

Don't worry about trying to follow my current train of though... I can hardly myself.

Also, did I mention one of the B8EV plugs had a broken connector inside the spark plug boot? Also, they were all finger-tight. Or rather, finger-loose. There's no way to tighten them with a regular socket. There was also a thick oily carbony buildup where it had been leaking compression past the threads. Yeah, this is truely THE worst ignition setup on a rotary project vehicle that I've ever seen in my entire life!

I'm going to find out which plugs the owner would like to use. His choices are:

B8EV are expensive (just gotta get one more and a thin-wall socket)
BR9EQ-14 (stock for GSL-SE and good with streetported engines, like this one)
BR8EQ-14 are cheap at Schuck's (stock on 12A FBs but may be too hot for streetports)

He's gotta do something within the next few days. I recommend BR9EQ-14s.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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Jeff20B


Moderator
Posts: 661
posted September 09, 2003 09:17 PM
Edited By: Jeff20B on 9 Sep 2003 21:24

Here's another update.

I rewired the fan and the fuel pump on Moday. I also installed two relays. The old key switch wire did have a finger twist job and a butt connector; both at different locations on the wire, and both were covered with electrical tape. Yuck! Anyway, I clipped it up to some good wire and then used a new butt connector with three slightly smaller wires Y-ing out the other end. One went to power the fuel pump like it did previously (only this time it's the only thing actually consuming any power from the key wire), and the other two go to the relays. Since relays don't really suck up any power to speak of, the fuel pump now has plenty of juice. I also ran two 10AWG wires directly from the battery over to the relays. The fan now spins faster than it used to. I also installed the third coil in a convenient spot using some existing threaded holes on the inner fender well.

Today I cut and drilled an ignitor plate (yeah, real busy today lol).
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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Jeff20B


Moderator
Posts: 661
posted September 10, 2003 10:20 PM

I installed the three GM HEI ignitors on the aluminum plate today and also gutted both dead J-109 ignitors and soldered the pins. Luckily the wiring harness is the style that has three black wires with white stripes that join far from the connectors. I've also seen the kind that has them joined near the connectors. Again, luckily, this is the better type to do this kind of an ignition mod with.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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Jeff20B


Moderator
Posts: 661
posted September 12, 2003 11:08 PM

It runs! There are less flat spots in the carb (Holley 600 or whatever RB recommends for a mildported 13B). It still has a lumpy idle, but just off idle it's smooth. I think I may need to add a shield to the pickup wires because they're really close to a few high tension wires. That might clear up the lumpy idle. Possibly. I'll see if the owner is happy with it as it currently sits. Otherwise, it's done! Now on to other projects...

Since this is the first time I've messed with GM HEI ignitors, this setup needs to get past the first 90 minutes of operation before I'll know whether it's going to work or not. So far, so good.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
View IP (Administrators only)
Jeff20B


Moderator
Posts: 661
posted September 13, 2003 10:12 PM

We put in some new BUR7EQs in the Leading holes and BR8EQ-14s in the Trailing holes. It runs a lot better now.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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