Ok so we've had the car on the dyno tuning for pump gas and run into what seems to be an electrical problem. The car completley loses igniton for a moment on wot, it has done it at various rpm from 5000-8000 each time. The car doesnt stall it feels like its hitting a boost cut.. I can free rev up to 8k and also drive the car at light loads up to 7k with no problems. We have swapped out a spare CAS and a spare MSD DIS 2 but no luck. Tomorrow i will check power and earth to everything but it seems weird that it will only cut at high load. I dont think this is a vibration or loose wire as the car runs fine, all other times it is very smooth, no probs.

Any tips guys?
Cheers

 

So... is it tuned?

Are you logging this with evoscan or something?

 

it has a Haltech ECU (old E6K), looking at the data log doesnt show anything abnormal. The tune was getting close, just dialing in the afr's and timing then the problem started, we got a few clean pulls to 9k beforehand. Any suggestions would be helpfull at this stage.

 

post a log of the pull with these items being logged:

http://www.mellontuning.com/process.html

 

thanks mellon, but i have no way of loading the log onto this PC, the ecu can only log when the laptop is connected and it doesn't have windows based software (dos) i told you its an older ecu So far we tried a different cas, coil pack and msd as i had access to them so thought its worth a try.

 

you may be hitting boost cut, wanted to verify it by looking at the log

 

As a weird tangent here,

How old are those plugs your running and what kind of gap? People often will run into spark blow out with old plugs and wider gaps when the boost reaches a certain point.

 

No its not a boost cut, thats one of the first things we checked. Strange thing is the car seems to be getting progressivley worse, when on the dyno it would get some clean pulls to 9K then started cutting out around 7k, now it wont even make 15psi before cutting.

the plugs that were in it have done about 1000miles running the engine in, i swapped them last nite to a new set of BR7ES and no difference. plug gap is .75mm
what else could this be?

 

plug gap is .75mm

 

try .55mm gap, that's too much.

 

thanks mellon, it ended up being the leads. pretty strange as you would think if a lead was dodgy it wouldnt be cutting ignition to every cyl, had the leads tested they seem ok but putting an older set on the car fixed the problem. Go figure.

Now ive got another problem, my static igntion timing is changing by iteself! here's the thread https://www.evolutionm.net/forums/ev...ml#post7065876

 

that's great, I'm glad you got it sorted out

 

when you say its the leads what do you mean what do i need to swap out

 

So I know this post is pretty old and I know the original post is even older, but I’m hoping for help with the same issue. My evo will rev up fine sitting in one spot, but you put a load on it and it will just cut ignition for a split second. Almost like loosing boost or fuel but looking at the tuning software fuel and boost are fine it just shows a quick loss of ignition. I’ve replaced the CDI plugs and coils and hasn’t fixed a thing. I put the stock coils back on ( stock coils came off another high HP evo that runs great) and nothing, still does the same thing, it’s pretty sporadic, some times it will run great with no issues and other times it will do it at an RPM Range from 4500-7000.

Any input would be greatly appreciated!!

 

Have you figured it out ? Mine does the exact same thing..it just one day decided lt was going to start this ..it will damn near put your chest in the steering wheel when the "cutt" happens. Logging shows a sudden drop in timing with the cutt off..its infuriating)