Just Another Civic

Background info:
1990 hatch, turbo b16a, autronic smc ems, modified distributor with 2 hall effect sensors. (distributor has had oil seal replaced; couldn't cross-reference seal and NOK dosent make one so it is correct on ID, small on OD so it is epoxy'd in, still has slight leak but nothing near any of the contact points. Also had bearing replaced. Has minor shaft play when shaft is out, but very very minimal when shaft is seated and rotating in seal.)

About a week ago my car started acting up. It misses/breaks up... the tach jumps like 1-2 grand either way of my actual rpm. For example if I'm crusing at 3 grand its jump crazily for a couple seconds in the range of 1-5 grand.

It mainly happens during decel and started out only happening when the car was warmed up. Now it still mainly happens during decel but even when the car is cold. Plugs have been changed, wires checked for resistance, swapped out my coil for a definte good one from a friend. Checked timing, rotor is new. All the connections going to the distributor are correct and secure.

It has to be electrical and related to my distributor (or just the distributor itself) being that tach jumps around as it does.

I am mentaly exhausted from this problem. I am sold that the distributor is at fault and that I must spend too much money on buying MSD's distributor I just want some input before I pull some dumbass move and spend $400 and not fix the problem.

Dragline

I would say it's your dist. you really shouldn't have any shaft play. If you have play by wiggling it with your hand,I can amagine what it does when under A load.

Get A new dist. thats your problem.

Just Another Civic

So I did some datalogging today while it was acting up....and this is weird. I lose cyl/sync but it has NO relevance on the RPM spikes. They don't happen anywhere close to each other. Now I'm really confused

turbo_civic_si

could be a faulty haul device. does the system have some sort of a filter on the input for the hall device? it could just very well be that the hall device does not have a very good signal. i would like to see pictures of your modified dizzy.

Just Another Civic

There are no filters for the hall effect sensors.

I was at first worried that the one sensor was being shorted out as it sits up against my VTEC solenoid. But I checked all the wires and threw some electrical tape around them just for precaution.

I'll take pictures of it if I have to yank it off for any reason but at this point I'm just leaving it on. Its just a gutted distributor with the center reluctor removed and 2 hall effect sensors put in. One mounted to a sheet of aluminum bolted inside the dist. and the other bolted on through a welded ring in the side. The cam p/u is the lobed 1 tooth reluctor and the crank is a 4 tooth reluctor wheel. Its very basic.

turbo_civic_si

are the wires soldered, twisted together, or crimped? i would highly recommend soldering them and use some heat shrink if they are not soldered. try adding a ground wire near your dizzy, perhaps it is getting some noise. i would definately try another dizzy, but a stock one. i work with hall devices, but as a position indicator, so sometimes signal noise is a problem. unless you have an oscilloscope, you can really see what is going on with the hall device. what hall device are you using?

Just Another Civic

The wires are not soldering, I'm using deutsh connectors. I do solder and heatshrink most everything, although there are certain apps. which i will butt connect as soldering dosent have the flexiblity of a crimp. I will try adding another ground. I did re-do my grounds thinking that might have been the problem, didnt fix that but made my starting easier I can't use a stock distributor with my ems and am looking at fixing this problem rather than buying MSD's fortune 500 distributor.

I just called my tuner and hes coming over tonight so hopefully we can figure this out.