Hello all. Forgive my noobism but I've created a conundrum for my self.

Here is the story: 94 22re Pickup, 125k miles. Installed a cheap tach and got the RPM signal from the IG- connector on the diagnostic port. The tach had quite a bit of lag when the engine changed speeds. It seemed like when you hit the clutch and take your foot off the gas, the tach would SLOWLY go down to idle, much slower than the engine actually changed speeds.

So, I thought maybe the IG- connector was an RPM signal out of the ECM which would have digital lag. I did some googling and tried to hook it up to the coil itself and thats when all the trouble started.

I tapped into the black wire off the ignitor and the engine wouldnt start. I thought maybe I tapped the wrong wire so I cut it. Now the engine dies after about a minute. Sometimes it dips out and comes back, but most of the time it just dies. I think there is an intermittant short because for a while when I would jiggle wires, I would hear a relay going off and on. When the engine dies, the engine light would NOT come on until a few seconds later, as if the vibration of the engine was wiggling the shorting wires.

Any ideas??
Thanks in advance.

 

Fix the wires you cut and/or tapped into would be the first step.
If you can't fix them properly, replace them.
Toss out the tach and get a new dash. Look into a dash swap, I believe all the wires are there just tucked away. Lots of info on here for dash swaps.

 

Thanks.
As far as I can tell, I fried my ignitor and have a lead on another one. Hopefully it fixes the problem. I may eventually swap dashes but that is a LOT of work!

 

Did you tap into/cut the black wire, or the black/white wire? The black wire is the same one that goes to the diagnostics port (and to the factory tach), so you should have gotten the same results as when you tapped into the port. The B/W wire goes to the coil, and cutting that will certainly shut you down.

The cheap tachometer is probably just averaging and filtering the ignition pulses, which at 1000 rpm is only about 50 pulses/second, so it takes a few seconds to get enough information for the tach to display an accurate speed. The better ones (like the factory tach) count microseconds between ignition pulses, so they get all the information they need in a fraction of a second.

 

Thanks, thats quite helpful. It was definitely the b/w wire.

 

So my the guy who I met with had several. The type I needed was in the truck hes restoring!
The rest were the wrong version.
Anyone have one they could ship to NorCal for a reasonable price? I can PayPal you.

 

Igniter swap made no difference. Anyone have any other ideas?

 

was the re[lacement igniter used? if so , it may not be good. put everything back to the way it was before you started this mess , check and recheck your wiring. get it running before trying to add a tach again.

 

isnt that a fused circut for the igniter? could it be that simple?

 

blake might be right. i got my 87 from my aunt.her brother tried to jump start it and crossed the cable.truck would not do anything.found the main fuse fried,replaced it ,truck would crank but not start.replaced blown fuse in interior fuse box.ended up being the igniter anyway , but can't hurt to check fuses.

 

would it run at all with a blown fuse? ill check them tho! you might hear me kicking my self from all the way across the internet if that turns out to be the problem.

 

all the fuses in the main block appear to be ok. would there be any reason to check the ones in the cab?

 

just reread that message. ill check the interior ones in a bit.

 

all interior fuses are good.

 

put all back to the way it was before adding the tack. replace igniter with new or one from a running vehicle.you should run then. if not , there has to be another problem.

 

replaced ignitor with one from that supposedly was running well. the tach is not hooked up and it made no difference.

 

ok.refresh my memory. does the truck crank but no start?

 

truck runs for about 30 seconds, then runs super rich and dies.

 

to clarify, it runs super rich for about another 30 seconds THEN dies.

 

so it turned out to be an intermittent problem from a completely unrelated mod i did months ago and never had a problem with. i must have bumped a crimp because one of them was loose. ˟˟˟˟en A!