JDM k20A misfire as soon as boost hits. PLEASE HELP!!

K-Series Programmable ECU installation questions / support issues
Post Reply
welen78
Posts: 8
Joined: Fri Mar 29, 2013 10:23 pm

JDM k20A misfire as soon as boost hits. PLEASE HELP!!

Post by welen78 »

I am trying to help a guy and tune his car and the car is a Ariel Atom with a jdm engine and a prc ecu that is fitted with a kpro.
Detch werks 1300cc injectors
e85
precision turbo, I think it is a 58mm
intercooler
wastegate and bov. non recirculated
hondata 4 bar map sensor
prc hondata ecu
return style fuel system
k-manager 3,2,4
37820-PRC-023
2070-403583

As soon as boost hits and the load is over 1000 mbar in any gear, rpm, or tps the engine starts to misfire. It sounds just as if the engine is only working on 3 cylinders at that time. I hear it very well on the dynopack but it is not very clear on the road. The higher the gear on the road the easyer I hear it. On the dyno I´m in 4th gear.
I have looked the cam angle in 10deg in the camangle map and is only working on the low speed cam and set vtec high to 6000rpm and is only reving under that. I have tried setting ignition timeing to anything between 10 to 25 degrees in the area that this accur. I have done a compression test and it was fine.
I have tried a known working set of coilpacks.
I have tryed new sparkplugs.
I have tried starting from different base maps but has the same problem.
I have tried to erase the ecu and upload the calibration again and no luck. Still the same problem.
Sence it is a prc ecu I have unchecked the "VTEC oil pressure switch enabled"
I dont get any error cods


I cant find anything bad in the logs ether.

The guy that built this turbo kit had the stock lambda between the turbo and the head on the "long runner" turbo manifold and it doesnt read the same as the dyno lambda so I have just not payed attension to the stock lambda values in the logs very mutch.

I have noticed that when I am online with the ecu and datalogs. Not record. There are flashes happening in the mapcells randomly. Also in the data logs it logs the MAP signal but the graf is a stright line at the top. Klicking at the area I get a MAP value but not a curve.

I keep going through the parameters but cant find if I have done something wrong. The calibration is still just a rough base map. The log attached is from driveing from the dyno and home.



PLEASE HELP!!
Attachments
bost truble log.kdl
(5.16 MiB) Downloaded 130 times
Dag 3 forts 10 deg 3500 fuel.kal
(101.5 KiB) Downloaded 128 times
User avatar
Hondata
Site Admin
Posts: 10434
Joined: Thu Aug 15, 2002 12:13 pm
Location: Torrance, CA
Contact:

Re: JDM k20A misfire as soon as boost hits. PLEASE HELP!!

Post by Hondata »

I think the o2 is going to die if it is before the turbo. What are the spark plug gaps?

Why is it not running in closed loop? VTEC at 7000 rpm? Only 10 degrees cam angle? Stock injector dead times?

The AF goes super rich in places - 11.5:1 at light throttle, 11.4:1 at idle. The injector overrun cutoff is not working either.

I would start with a new calibration and import the fuel & ignition tables. Set the injector dead times, then tune the fuel. Also consider that the o2 sensor may be mis-reading since it is close to the head.
Hondata
welen78
Posts: 8
Joined: Fri Mar 29, 2013 10:23 pm

Re: JDM k20A misfire as soon as boost hits. PLEASE HELP!!

Post by welen78 »

Thanks for the reply.

The turbo system is built on a long runner NA header.. Like putting a turbo at the end of a 4-1 NA header. The lambda is pretty far from the head but it sees a lot of heat and is probebly damaged. The dyno lambda shows a leaner value.

I turned closed loop off for tuning and because I dont trust the stock lambda is working properly. It has probebly been there for some time and I am suprised it works at all.

I have not gapet the new plugs but the old ones it had, had been gaped severly and the engine had the same problem.. I can messure later though. I dont think the spark plug gap is a problem sence the problem is consistant at any rpm that can be loaded over 1000mbar. From about 2-2500rpm to 5000-6000 rpm. Vtec is set high because I want to do the low cam only first. The plugs are NGK BCPR7ES. I will try gapping them to about 0,025" and see what happens.

The map posted is a tune I have began with only and is trying alot of stuff in to see if I can solve the problem. So I have done the 0 deg fuel map and began on the 10deg fuel map for low cam. I dont want to continiue tuning until I have solved the problem. Otherwise I might have to do everything all over again if the cure effects the hole tune.

I have tried both disable and enable the "fuel overrun cutoff deley" but the problem is the same. I took the dead times from a DW1000 injector calibration I found in the vault if I remember correctly. I did not know those were the stock ones though. I will find them out and use them later. The dead times should not be the issue here though I think.

I have disabled the knock sensor and the stock knock control logic and put all the knock tables values to zero. I will try the knock values from one of the base turbo calibrations and see if those has anything to do with this even though I disabled the functions under knock/TPS parmeters.

I have tried alot of differant base maps but I have the same problem. I will do it again though and try anotherone.

I pulled the plugs a few days back and number 1 (closest to the camchain) I think showed lean and the number three plug was not as much but simular. The number four and two looked normal.

I borrowed a set of 440cc injectors and will try those also.

I´ll get back with the results.
welen78
Posts: 8
Joined: Fri Mar 29, 2013 10:23 pm

Re: JDM k20A misfire as soon as boost hits. PLEASE HELP!!

Post by welen78 »

Can I use both PRA and PRB calibrations for my PRC hondata ecu as long as I disable the vtec oil pressure switch under vtec parameters??

Or does it has to be prc/prd based calibrations?.. Cant find any of those...
User avatar
Spunkster
Site Admin
Posts: 22741
Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata

Re: JDM k20A misfire as soon as boost hits. PLEASE HELP!!

Post by Spunkster »

You should use a PRB based calibrations for a PRC ECU. PRA does not have a wideband and may cause you some issues.
welen78
Posts: 8
Joined: Fri Mar 29, 2013 10:23 pm

Re: JDM k20A misfire as soon as boost hits. PLEASE HELP!!

Post by welen78 »

I tryed the rev hard turbo map in the k manager software and had the same problem. I tryed the dw1300 deadtimes and the problem was still there. I then borrowed a set of 440cc injectors and changed out the DW 1300cc injectors and the problem was gone. I will switch back and see if the problems comes back when I put them in again in a week or so when I have more time.. In the mean time I will probebly order a set of ID 1000cc injectors.. I think that would be enough for 450hp on e85.. I will calculate on it later to see if it will work...

Thanks for taking the time to help me out.. I will get back when I have Everything comfirmed and tuned..
welen78
Posts: 8
Joined: Fri Mar 29, 2013 10:23 pm

Re: JDM k20A misfire as soon as boost hits. PLEASE HELP!!

Post by welen78 »

Sorry I forgot to get back here.

After I tried the 440cc injectors the problem was totaly gone. I ordered the bran new ID 1300 with stainless internals that should work perfectly with e85.

It took a while to get them here to Sweden but after I got them I tuned the car on a dynapack and the result was 396whp and 310ft/lbs of tourqe on 15psi of boost on a 58mm ballbearing precision turbo. The ID´s was a Dream to tune. The exhaust backpressure started to open the wastegate on anything more than 15psi and the owner was sattisfied with the power it made so I stoped there.

This Ariel atom has almost 1hp/kg and is a absolute missile! Doesn´t spin very much ether since it´s so light..
Post Reply