MS3X on CA18det high rpm/boost problem

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Flavius424
MS/Extra Newbie
Posts: 4
Joined: Sun Aug 31, 2014 1:29 pm

MS3X on CA18det high rpm/boost problem

Post by Flavius424 »

Hello !

I'm new on the megasquirt community, I have done a new setup on my CA18det S13 on MS3 + MS3X last year.
I have some issues since I have installed the MS on this engine and no answer for the moment...
I'm From France, sorry, my english is not perfect...

First, the setup :

CA18det fully forged 1853cm²
270° 10.25mm intake and exhaust cam
Holset HE341 turbo
1600cc injectors
Denso/toyota COP
36-1 trigger wheel on cam with hall sensor
homemade mil-spec harness
E85 fuel

The engine run good in many situations but I have a problem on boost and high rpm.
When I run WOT, the engine run good until I go to approx 6000 rpm (depend of the gear, and of the time on full boost), and the engine start to misfire a lot, like running on 2 or 3 cylinder, no combustion, AFR go to 18+ (ultra lean), no power and the rpm and boost go down.

You can see a screenshot of a datalog of the problem :

Image

After doing some calculation, My fuel pump (350l/h) will be a probable cause, I have upgraded to 2x 350l/h in-line and 2x An6 hose to the fuel rail.
But nothing changed...
The pressure on the fuel pressure regulator is OK, no variation on boost (If you see the log, the fuel pressure on the log is out one pump, no on the regulator, some variation, but I think is because of the long harness extension).
The logs of the hall sensor are ok.
I have tried a lot of spark plug, with different gaps( 0.4mm to 0.8mm), no change.
The coils are new, is it possible that one have a defect and cause this problem ?

Now I don't know where to look to found the solution of this problem...
You can see my tune and log file on attachment.

Thanks a lot !
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: MS3X on CA18det high rpm/boost problem

Post by Matt Cramer »

What's your fuel pressure doing at this point?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Flavius424
MS/Extra Newbie
Posts: 4
Joined: Sun Aug 31, 2014 1:29 pm

Re: MS3X on CA18det high rpm/boost problem

Post by Flavius424 »

The Fuel pressure at the fuel rail is doing the same thing as the boost pressure. (I have see that on some previous log, now the sensor is just after one of the too fuel pump : )

After the fuel pump :

Image

(Yellow, on the first graph)
The pressure is not stable but it was worst with just one pump... and the harness between the ECU and the sensor is extended a lot to put the sensor after the pump, like 7/8 meters... it possibly doing perturbation on the reading...
But no change of the problem with too pump... and too AN6 hose to the rail...
Flavius424
MS/Extra Newbie
Posts: 4
Joined: Sun Aug 31, 2014 1:29 pm

Re: MS3X on CA18det high rpm/boost problem

Post by Flavius424 »

Suite of the tests !

I have tested the voltage at the coil entry, motor running in static, idle to 8000rpm, no move of the tension, stable 14 to 14.2v depending of the coil.
after, I have fixed my multimeter to the windscreen to see the tension on driving, the voltage drop to 12.7v at WOT and 1.5b, I think it's OK.

And I have do some videos :

https://www.youtube.com/watch?v=g-XlXnu ... e=youtu.be

The fist, in 2nd gear, burning the tires... hitting one time the rev limiter, and no power, spark cut or others... with drop of rpm

The second :

https://www.youtube.com/watch?v=LMGA7Bs ... e=youtu.be

I do some tests in 3st gear and the first in second gear, at middle throttle, but have the problem too...
At 1min25, I put WOT on 3st gear, spark cut too, you can see the AFR in my AEM gauge or on my dashboard (gauge on the bottom left of the rpm gauge, flash red when it hit 18+ AFR)
At 1min 40 I put full load and I release for 2/3 time and recovery directly at WOT, it Works 1/2 second and it cuts again, every time.
At 1min50, on 4st gear half load, but it hit 1.5b of boost and cut too...
Same at 2min,
the last shot, I'm on 3st gear, little throttle (a little too early and it also cut because I hit 1.5b) then after I release a lot to take a little positive boost and the motor run good and take his rpms ;)

Thanks for your help !
Cheers,
Flavien
Flavius424
MS/Extra Newbie
Posts: 4
Joined: Sun Aug 31, 2014 1:29 pm

Re: MS3X on CA18det high rpm/boost problem

Post by Flavius424 »

Up... Help...

Yesterday, same problem but at all load... even at idle.
The engine don't run at idle, stall after 3/4 seconds...

Image

The log when I mapped the car yesterday, the engine stall... AFR at 18+ with very low load, impossible to drive...

Thanks you !!
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