Wouldn't you be excited if you just got your new AEM EMS?

I was. Till now.

OK, so it was probably mostly my doing, but bear with me here... I loaded the base program for my 99 EX, and hoped it would start. AEM tech support had me check for spark. No spark.

For those who have the EMS and are interested to see where I screwed up... here's what I did:
I fiddled with a few options, mostly the Cam = T4 setting under "Cam/Crank P/U options" and the "Engine Cranking options".

Under "Engine Cranking options" I changed the crank advance from 20 degrees to 16, to 8, 5, 0, and -9 in desperation... Nothing. Crank exit speed from 400rpm to 500rpm. I also checked off "Ign Invert" in hella desperation under "Coil Control Options."

A couple times, the revs got up to 1100rpms or so for just under a second , and died.

I must have tried at least 10 combinations before I gave up and put the stock ECU in...

... and found out that the car no longer entered boost. The car backfires, and stumbles so hard it falls out of boost (by boost, I mean the car can't get above 0.5PSI!). I suspect the coil's fried, the ignitor chip is fried, or the entire damn distributor assy. is fried.

I smell fuel, so I know the fuel system should be OK. It's backfiring, another indication of an OK fuel system.

It starts just dandy. It idles just fine.
Vacuum at idle is as same as before. WOT blips of the throttle in neutral yields a slight stutter between 2000rpm and 3250 or so, the rockets up to redline as before. It's interesting to note that I can't boost in neutral anymore. It used to be I'd get 2psi.

All I wanted to do is START the car with the AEM EMS, and drive it around to monitor engine stats for now. And I get a car that I can't even drive normally? Sigh...

So y'all think it's the distributor, or stuff inside it? Or maybe alllllllll that unsucessful cranking got the catalytic converter or O2 sensor so tripped out they're screwing up?

I've been getting 4 error codes via the CEL: codes 71-74: Engine misfire in Cyls 1-4. No kiddin. That would explain the uneven stuttering.

I'm going to take it apart tomorrow and take my multimeter/VOM up to it.
Help!

 

Well, the lightbulb went on and I decided to yank the plugs. Black as all hell. Might be a good reason too, considering I was flooded the cyls with fuel!

Replaced the plugs, and I can boost only 5psi before it starts stuttering again (think of it as a rev-limiting RPM bounce, but lets me go up slowly). Only advancing the ignition can I get to the 5psi (meaning advancing it back to stock), and gapping the plugs to 0.030". I'm going to try 0.026" and see if it's any better.

Any other tips?

 

you may want to give this forum a shot.

http://www.aempower.com/bbs/login.php

 

Been there... nothing relevant...

 

I would redownload AEM's base calibration You are obviously getting spark if you are running 5psi of boost.


[Modified by quick108, 12:21 PM 7/16/2002]

 

A day after I put the plugs in, they're fouled again!

What could it be? O2 sensors? Ignition???

It runs fine up to 0.5psi of boost again... sigh... this is aggrivating...

 

If you are driving around, I am sure the spark is there. You, most likely, need to take fuel out of your map. What is your Air Fuel Ratio?


[Modified by quick108, 12:23 PM 7/16/2002]

 

I'm driving around on the stock computer.

I can't get the AEM EMS to start, so I can't even take fuel out or check A/F! That's why it's so frustrating for me!

I'm going to pull the plugs again to check... sigh...

 

Did you try downloading AEM's base calibration?

 

Yes, I've contacted AEM and they've guided me thru everything... no worky!

But the bigger problem now is just getting my car to run properly on the STOCK ECU, let alone the EMS!

There has to be something electronically wrong.

Now I'm suspecting all that raw fuel damaged the O2 sensors...

Plugs are way black, as are the tops of the pistons.

Another CEL: 71--Misfire in cyl. 1!

 

This might be a long shot but you might have fried your ignitor. These Hitachi units are notorius for going out for no apparent reason.

 

Hopefully not... it's a $170 chip!
Interestingly enough, I have the TEC distributor, not a Hitachi unit...

I took my multimeter to the chip and it checked out ok... This just odd!

 

Did you reset the ecu?

 

it would automatically

 

Yes, I reset the ECU... it's been out of the car quite a few times!

I read my auto shop textbook some more tonight... Methinks it's the coil... In the EMS forum on AEM's website, the AEM support rep suggested that I ground the spark plug wire boot against the valve cover to see if I had spark.

It wasn't until today that I realized that of course there was no spark--that's a 2-3" gap that the spark has to jump! The coil must have one helluva time trying to build that kind of voltage to jump that gap, and in doing so, must have damaged it. Incidentally, I tried doing that with the stock ECU in place--it wouldn't bridge that gap either.

My textbook indicated that when doing a compression test, it's always necessary to ground out the spark, else the coil would be damaged. Reasoning behind this is when the spark goes from the primary resistance to the secondary resistance, under circumstances where the spark has a tough time finding a ground (e.g.: trying to bridge a 3" gap), the voltage spikes enough to bypass the secondary resistance altogether and goes right to the exit coil. In bypassing the secondary resistance, the high-voltage spark damages this less dense resistance.

When testing a coil using a VOM (multimeter), however, this won't show up. The book indicated that the car would still idle and work under light throttle conditions--exactly my situation! Only when under load would the symptoms such as misfiring would show up--a condition that wouldn't be tested w/ the VOM. And exactly my situation again--this condition shows up only under wide throttle openings.

All said and done... lemme at a new Crane HI-6S ignition and a new eLX-92 coil... I'll show the damn engine what a REAL spark is!