H4Inf

I'm driving a 1982 13B with injection. 1000cc primary injectors. microtechdigi series 1 pro in the glovebox with manually attached leads + pipe.

Anyway had my first drive of it tonight, and boy is it a handful. If i'm under about 3400rpm, i can see the tacho just jumping up and down erratically... is this normal?! what could cause this?

Only owned it a week... still over 3500-4000, after planting the foot, she's smooth as...

Some current problems with it I forgot to include before:
- the single and only fan belt which connects engine, alternator and waterpump is loose
- the pinion and ext. housing seal need replacing
- umm the clutch... you really have to bring it out a lot before it grabs..

Thanks guys,

Paul.

~*Nector_Rivera*~

There could be a loose connection with the tach. wiring. Mines did the same shrtly before it went out due to stripped wiring. Check the tach connections that should solve the prob.

high-RPM

~*Nector_Rivera*~

was the tach fixable with the stripped wiring?
cuz mine was doing the same before it, errr... stopped working??

H4Inf

I'll check the wiring today, but its not just the tacho - the car is seriously hard to drive under 3500rpm - it will be jumpy.... Really hard to stick to low speed-limits.

H4Inf

Okay this morning I adjusted the tension on the belt by lifting the alternator a little.... damn she runs fine now at low RPM

I'll be looking at getting a new belt, and a second one to connect the water pump to the engine as a backup..

Since now I'm pretty sure the bad performance at low RPM was caused by this loose belt, does any one know which component may have been causing this problem???

Does the water pump directly affect performance? Or would it be the alternator .. I thought everything ran from the battery pretty much and the alternator just recharged it... OR maybe it was the slipping of the belt suddenly putting more load on the engine?

Happy to have this happening again, shes wonderful to drive

~*Nector_Rivera*~

High-rpm

The prob was easily fixed by locating both faultyn wires removing them and replacing them. This also caused a problem with the first ignition coil not allowing the car to turn off beacuse it gave it some ground. Everything with that is fixed now...but other problems arised this weekend.

Feds

Seems wierd that a loose belt caused eratic running at low RPM, unless the voltage was marginal due to belt slippage. Depends how sensitive your standalone is to changes in voltage I guess.

Before I read the fix, I would have suggested that the 1000cc injectors are too big. that can make it difficult for the ecu to control fuel at low pw.

web777

Usually when your tach acts funny, it's your trailing ignitors going bad.

faye x7

Exactly what I was gonna say.

ray green

iTrader: (14)

Originally Posted by web777

"Usually when your tach acts funny, it's your trailing ignitors going bad."


'Exactly what I was gonna say."


Exactly what I was gonna say. Mine did that, I ignored it, then it stopped running and I had to tow it home. The diagosis was no fuel, because the fuel pump also cuts out when the trailing ignitor goes bad (Mazda engineers). Now, the motor runs pretty good without the trailing ignitor, so you might not notice (speciially with all those other things you got going on) but when it turns off the fuel, you notice. You can hot wire the fuel pump (ask me how I know) and get it running again (ie, get it home, no tow charge next time), but best to just pop in one of those ignitors (about 15 minutes, I got 6 for $15 on ebay a few weeks back, email me) and away you go.

Ray

GavinJuice

From what ray green said about the trailing ignitor being directly related to the fuel pump operation, would this also work with a DIS system from a second gen. I have a friend that is having some problems starting his car and with it idling when cold, and now supposively his fuel pump is not running at startup? Sorry to gank your thread, it just kinda popped in my mind.

H4Inf

Trailing ignitors, forgive me for asking, but what are these and where are they ?

Cheers!

ray green

iTrader: (14)

There are two ignitors - leading and trailing. They are matchbox-sized black plastic things attached to the side of the distributor (or maybe someplace else on older 1st gens, as I recall) and they have some wires hanging out. I'm not an expert on what they do, all I am sure of is that if your tach starts having fits and then quits all together, your rear ignitor may be failing. When it finally fails, it shuts off the fuel pump and your car stops running. If you hot wire the fuel pump, the car actually runs pretty well, so whatever the rear ignitor does, it's not essential. My guess is that the ignitors are responsible for "igniting" the combustion mixture, via a precisely timed pulse to the leading and trailing spark plugs, and rotary engines can run pretty well just on the leading plugs.

Ray

Jeff20B

iTrader: (13)

Like a yoohoo belt? 3L220

I had an screwy tach in a recent rotary project. I think the wire4 was too close to the alternator. I rerouted the wire onto one of the leading coils (it had DLIDFIS) and the tach read perfectly. Maybe your tach signal wire is picking up some electrical noise?

That's cool that you have EFI on an '82 13B. Would you happen to know what castings are on the engine? I bet they're R5 castings (front, intermediate and rear cast irons).

H4Inf

Thanks for all the suggestions, I'm gonna get a new belt to begin with, look at the ignitors and check out the distributor contact points... Just seems weird that she runs fine with the belt more tight.

I'll check for nearby cables... My car chassis is 1982... I'm really not sure on the engine though.. Will it say anywhere on it ? I still havent had a chance to really get under it. Heres a pic of the engine if it helps..



Will get back to you folks in a few days, got to work to afford the 7 ... worth it but

Cheers

Jeff20B

iTrader: (13)

Yes, it actually helps quite a bit. Here is some info for future reference. Just because the chassis is an '82 doesn't automatically make the engine an '82 (you seem to already be aware of the distinction, which is good). That 13B is an '86 or later engine. You can tell simply by looking at the rotor housings. They sort of curve down into a V shape at the top while a true '82 13B (only available in a Japnese car) do not. You'll see what I mean if you look at lots of engine pictures for many years, as I have, or happen to own a true JDM 13B that dates between the '78 13B and the GSL-SE.

One more thing, you really need to remove the tube connecting the two vacuum things on the distributor (people here call them vacuum pots but they're actually diaphrams). Leave the nipples open so the diaphrams are free to breath.

H4Inf

Thanks for that info... What does the tube connecting the vacuum things do?? How will it affect the car? Loudness? Performance? Smoothness?

Cheers mate!

H4Inf

Vacpots

H4Inf

OK Guys I have myself a new theory about the tacho jumping erratically

I took her out for another spin tonight and noticed something... I was going up a hill in say 3rd gear at about 2000rpm... The lights were dim, indicators going slow... then suddenly she died. Started her up again... and it was the classic erratic jumping RPM.

But I noticed this time the voltmeter is reading 8 volts.... and as before when doing about 3000RPM, she ran smooth as usual.

My theory is that the battery is gone. All these problems I have only had at night... with the lights on....
Edit: The EFI has got to be suffering from the unstable voltage correct? Not sure how the current is, may need to hookup an ampmeter.

May I assume my battery is stuffed, or is it normal for when the car is idling, and the lights are on, that the battery level drop to 8v... ? Maybe its my alternator... or even the belt connecting them?

Overall I think the alternator belt should be replaced soon anyway, its pretty old.

1. Is it normal for my alternator to be acting like this - only bringing up the voltage at over 3000rpm..

2. Is it normal for the battery to be sucked dry that quick, whilst idling at 700rpm?

3. What do you reccomend I do ?

Cheers guys, I would really appreciate some input. It just doesnt feel right when its acting up like this, would like to get some solid performance out of her :S

1984rx7roqet

Thats what I was going to suggst. When I had this problem it wasnt my ignitors it was the idiot at the garage that disconnected the battery and didnt put the battery cable back on correctly...it was loose. Make sure those are tight, and if they are go get a alternator.

H4Inf

Hmmm anyone know any more about this?

thanks,

Paul.

LongDuck

Seems like the easy fix would be to drop a new battery in there (known good) and see if it still exhibits the same problems.

The issue with the Tach jumping around has to do with the EFI ECU getting the fuel signal from the trailing ignition coil. This is driven by the ignitor which is used to 'ignite' the coil discharge to power the spark plug. You have both leading and trailing ignitors, so the next step (after battery replacement) would be swapping the leading and trailing ignitors to see if the problem still persists. They are the same part, just wired into the appropriate harness location to fire the leading or trailing coil. Ignitors are located on the distributor in 81+ cars, one on the front, and one on the side - I don't recall which is leading/trailing, but swapping them won't matter one way or the other.

Next step, if that doesn't work, would be to swap the coils to see if you have a coil going out. Judging that you're using the stock ignition system, otherwise, the coils are mounted half-in, half-out of the driver's side front fender panel, inside the engine compartment. The coils usually last a very long time, but these cars are 20+ years old now. Coils provide the high voltage current that fires the spark plugs. Simply swap the coils front to rear (Front is Trailing, Rear is Leading) and see if that fixes the problem.

Essentially, you want to get to a point that you're eliminating the problem. Once you find that you've fixed it, move the parts back to their respective locations and replace the offending unit. The duplicity that is afforded with our dual ignition systems makes this much easier that replacing parts from your local dealer ($$$) hoping that it will fix the problem - that's the worst way to try and tackle an issue like this. HTH, and nice car, BTW,

Something else that I was thinking of just now is that the fuel cut signal is also run by the trailing ignition/tach signal, i.e., the fuel pump won't run if 1) the ECU is detecting that the Air Flow Meter (AFM) isn't flowing air, and 2) that the ignition isn't firing (cranking the engine). If you have a bad connection in the harness to or from the trailing ignition, this will cause fluctations in the current carried to the ECU and could be causing your fuel pump to be surging on and off - detrimental to good performance through the powerband. Just a thought,

Oh, yeah, and ONE MORE THING; (aren't I helpful!), is to replace the 'IGNITION' fusible link located on your driver's side strut tower. The EFI cars use this as a master for the fuel injection system, and if the fusible link is bad, or going bad, it will cause your ECU to shut down along with the fuel pump. This is part of the 'unflooding' procedure that SE owners talk about from time to time (SE's were the US import version of the RE-EGI 13b cars...).

ray green

iTrader: (14)

Damn that longduck knows his sevens, the only thing I would worry about is if they run differently down there, like the toilets. Pretty engine, need some ignitors?

Ray

H4Inf

I drove her round during the day today without worry! No problems at all

So the symptom of lights on - car no good under 3000rpm = true

Damn shes fun to drive but! God damn! I'm exhausted

I'll get myself a new battery soon, and take it from there I reckon... Is there a way to meter how good a battery is ?

Cheers,

hornbm

happened to me a while back, turns out I was running so rich that my trailing plugs were fouled to **** causing a trailing misfire