Just looking for some advice on a problem that I have run into. I will be merging to get on highway or just doing some pulls and what happens sometimes is weird.

Ill be in full boost and the car at around 5k will like shut off? Just imagine you are in the car doing a pull and when you get to about 5k its like the car cuts fuel and spark the CEL comes on for a sec and the RPM's dive down to 0. The car doesn't shut off or blow any smoke, it's like the engine just cuts off but not really because it does but only for a second .

It doesn't do this all the time and when it does it mostly happens in 4th,5th gears. It has happened a couple times in 3rd.

I am taking it in to my tuner next weekend but wanted to hear some feed back from you guys.

The car is EJ8 LS Swapped and turbo'd, EMS is Hondata S300. I don't know anything about tuning which I feel is probably going to have to be either where I look or how it's tuned may be the problem? It hasn't always done this though so I don't know for sure I could point a finger at the tuning.

 

Sounds like it might be boost spike and you're hitting boost cut. Do you have a boost gauge? Do you notice it going over your tuned boost level when you have this problem?

 

Nope it stays at a solid 9-10psi which is what it was tuned at. And yes I have a boost gauge (AutoMeter Phantom)

 

sounds like ecu resets I would check all your connections. I almost hate to say it but had my hondata randomly resetting with old firmware; however the odds that your running the specific version with the problem is slim. If the ecu looses power for split second, you can data log it too. Other after market ecu's sometimes have verticle red lines or denote a power loss I forget how you tell with the hondata maybe look at the voltage graph. Just saying because hondata seems to be the most common.

 

Sounds like boost cut to me or maybe a main relay issue.

 

Correct me if I'm wrong but if you're running injectors without a resistor box can't it overheat the ECU and kill the injector pulse?

 

itll burn the injector drivers in the ecu. once that happens the transistors need to be replaced. He never mentioned anything about a resistor box so idk where you got that from

 

I am running high impedance injectors, that should only be an issue if I were not.

 

Either way a data log will help determine the cause, boost cut or what ever. What ecu are you running? If its an AEM you know know when it boost cuts, its tends to be violent. Hondata is a bit more gentle its like a stumble. What makes me think a ecu reset is he says his rpms goto zero and gets the check engine light, like when you turn the ignition on. Ecu reset are rare and I bet 90% of these people have never had it happen. I have yet to see an ecu drop your rpm to zero and check engine light when it boost cuts. I wanted to learn about ecu programming and picked up a megasquirt years ago, I installed it in an old ford. It was great learning experience, point being resets are fairly common with the megasquirt.

 

could be something going wrong internally inside you distributor, because your tach gets its reference directly from there. If your tach looses signal then your ecu is probably loosing its signal from the top dead center sensor or cam angle sensor. which means no ignition.

 

Like stated above, could be an ignitor issue in the dizzy.

 

When I have had ignitors go out the tach will be erratic but no check engine light, but who knows possible. I had very little warning till the engine wouldn't fire.

 

It's the lean protection in the s300 wen it's set to cut fuel+ignition if u go leaner than a certain condition it will drop the Rpms to 0 and cut fuel and resume once the condition stops and when ur tune is bad it may even stall the car LoL

 

Yea that's really the only thing it could be

The Hondata reset ecu was a very limited issue to a specific run of boards. like stated earlier it would be highly unlikely he has that version AFAIK Hondata has recalled those ecus and replaced them.

 

My Ecu still does this but my tuning has gotten better so I never have that problem anymore