Engine/Tuning Problem...Help me:(
 

All who don’t know, I am running a TecGT Standalone EM.

Well, this has been a little problem and has just now become a pretty big issue. Before I did the rebuild, my engine had an idle issue. Every couple of seconds it would Sputter, but it would catch itself. I didn’t really think much of it because it only did it at idle.

Right after the rebuild it did the exact same thing. But, now (4 days later) it does the same thing at all RPM’s. I would say that the frequency of the “Sputter/Misfire” increases as RPM’s increase. I am unsure if I could consider it or not consider it load based. It does do it more frequently under load, but that is whenever I am a little higher in the RPM range. Tomorrow morning I will rev it in neutral to see how it behaves itself.

Note: I put a Timing Light on it while it was idling and when the event occurs the ignition timing is significantly retarding and then comes back, I’m talking 30-40 degrees ATDC (according to Timing Light). I can’t say what it is doing at any other point, as I am in the car driving.

Things I have done up to this point:

I have checked the Crank Trigger and verified the spacing of the mag sensor
I have updated the Software and Firmware for the Tec
The Wires are new Magnecore 10mm
The Spark Plugs are brand new
I double checked grounds and cleaned them



I’m hoping that somebody can point me in some kind of a direction with this one.

Mike

Could your cas be bad? What year is your car?

If it is pre-1994, switch out AFM with known good one.

Well i thought for sure grounding issue but you said that was covered. Have you specked out your Coils resistance, ignitor. I think bruce was still a little asleep when he told you to try another AFM :rofl: but it is all good. So my money is on the ignition, parts ie coil etc.

Doesn't the TEC use it's own more powerful coil system?

No error codes from the Tec as far as CAS Errors. The car is a 2002. The CAS is from a 94-97. I'm getting a signal from the CAS at the appropriate time (90 Degrees BTDC).

This is a tough one. I called Electromotive and they're thinking about it too. Interesting.

Yeah, It has it's own coil system...which is brand new so I would pitch a fit if something was wrong with them.

The issue is that it runs extremely smooth, except for the sputter/misfire occurance. It's not necessarily random because it happens at similar time intervals.

Well, noticed one more thing that could help with diagnosis.

Whenever it is idling and it goes through this issue the A/F ratio leans out a little, from mid-high 12's to around high 13's and it starts to pop out of the exhaust. Maybe this will help someone...I'm stumped.

I'd consider putting scope on your ign signals. It helped me resolve a misfire where and ecu capacitor was filtering out my trigger signal above 4k.

How/Where could I go about getting a scope to check it out? I've never used one...

Oscopes are expensive as heck. Some mechanic shops have them though because lots of OEM components can be tested to see if they're working right with one. If you know of some good mechanic shops call them up.

I guess I am going to try re-routing all the wires to eliminate any chance of noise interference....:mad:

I can't find access to a scope

EDIT: I moved a few wires around with absolutely no luck. I don't think that it is interference related.

I have also verified that no connections are loose.

Maybe you need to look into shielded wire. You should only need it on the CKP and CMP wires coming from the CAS.

Someone hit him up the side of the head and tell him to read the whole posting next time.:vash:




Oh, wait, that's me.:gay:

Trust me mike, check the resistance and hell maybe you could stop by begi or somewhere similiar, to scope the output. FWIW I had a blaster coil on my nissan that would only short out on hard turns etc. Turns out it was the way i had it mounted and the coil itself not being able to take the G's. The coils on the tech are different but still if the capacatence has changed internally then it will cause you misfires and cutouts. + Like rob said if your signals are getting muddled by the ecu then a scope will most def show that. TV/PC repair shops should maybe have one as well. GL

The Cam and Crank Signal are shielded already:).

I didn't just overlook you:P. What kind of resistances should I expect? I'll have to try to get my hands on a scope somewhere. I think I am going to go to Ric's Shop Monday to test out a known good TecGT, mine has done this since I got mine. But like I said, it just now started doing it at all RPMS, used to just do it at idle. That way I can at least make sure I am not wasting my time with a unit that is acting up.

I dunno on our stock coils we have specs. I would take your multi meter and check the resistance between the 2points on a known good coil, and check the resistance of the external ignitor if there is alot of variance then maybe try to switch them for a sec and see if this helps. If it does then maybe you could switch to the new direct fire system ;) http://www.electromotive-inc.com/products/xdi.html

Well, Making headway...

Whenever I actually disconnected the Cam Angle Sensor the running smoothed out. So, I am going to take it apart and do a visual inspection and clean it up this afternoon.

Problem Resolved, It was the Cam Angle Sensor.