Help me figure out what this problem is before i burn my soarer!!

[-=DV=-]

ok guys ive recently been having this problem and both myself and my mechanic are at our wits end with it. so ill give the full details.

Car is running on a big single, was making 420rwhp for a while then i lunched my old 1j. so we built a new one, while i was at it i sourced a set of 440cc injectors and a few other bits and pieces. built a really strong 1j and stuck it in with the new 440cc injectors. drove it around for 2000ks to break in the new motor then took it back into the workshop to retune it for a bit more power.

we added an extra inline fuel pump to help things out and stuck a rrfpr on also. we Managed to squeeze around 480 rwhp out of it (estimate, dyno known to be outputting around 15% low for some reason...manufacturer wont support the dyno) without ignition timing adjustments and it was running great. When i took it home i drove about 2kms and it just started cutting ignition for a few seconds here and there. Initially under load or boost, but it got very bad very quick. to the point that I couldnt even pull out of an intersection without it cutting ignition and fuel and then dieing.

It seemed to be related to throttle input (as soon as i gave it any throttle whatsover it would just cut spark) so we replaced the tps and still had exactly the same problem. since then we have done various testing on and off the dyno and replaced the following trying to find the cause of it

ignitor
coils
plugs (several times. tried gapped to .7,.6 and even .5...no difference)
map sensor
tps
soarer ecu
emanage ultimate
crank angle sensor

The few times we have taken it on the road we have found the following

1. when its cold it runs great and makes more power than you could imagine with no problem
2. as it reaches operating temperature it starts cutting fuel and ignition for a second or so as you see boost or excess load
3. as it gets warmer still it will start cutting fuel and ignition completely randomly, with any throttle input or sometimes even just idling it will cut fuel and spark and die. then it wont spark as you are trying to fire it up.
4. if you let it sit and cool down the symptoms will downgrade and it will become drivable again.
5. if you let it cool completely then it will run like a champ and make super power again until it starts to warm up.

on the dyno we have noted that there is no problem with fuel pressure when this is happening.

does anybody have any idea whatsoever as we are completely at a loss we are going to try new cam angle sensors this week, although we dont want to go to all that effort if its not going to be the cause, we are prettymuch at the point that we dont know where to go from here.

[StuC]

Sounds like cam or crank sensor to me. They always shat themeslves when hot on the benzes. Put a scope on it before you pyll it out and check the signal line when cold. It will degrade and skip asit gets hotter if its at fault

[big_zop]

Firstly, I wanted to check you are running the Emanage as a piggyback with the standard ECU and if so, how are the sensors shared or cut in the case of fuel/ign/etc?

As a suggestion, I would look at the knock sensors and also the temperature compensation tables in the Emanage because while you say it cuts with the use of the throttle, it is also dependant on engine temp.

[-=DV=-]

thanks for the replies.

Stu we have replaced the crank angle sensor...and we have checked that the signal from the cam angle sensors is consistant and good.

Big Zop it is running piggybacked onto the standard ecu. The sensor signals are spliced or intercepted as the emanage manual states. Knock sensor is something we will look at when we get a chance. We will also have a look at the temp compensation tables as you suggested.

If its of any help, we took a series of logs from the emanage yesterday as trust had asked for some. I can email those to you if your keen to take a look.

[Cuzzo]

Are the coil packs split or cracked?

[-=DV=-]

cuzzo my original ones had been in the past but had been repaired. The ones I replaced them with are perfectly fine and came straight off a 400hp cressida with no issues.


I forgot to add, yesterday when we were playing around with it. It was playing up even when it was cold. So whatever is causing it is degrading. Hopefully soon it will stop all together then it will be easy to figure out lol.

[thechuckster]

fwiw: get rid of the Rising Rate regulator and put something like a SARD on it that doesn't do rising rate. RR is a PITA to tune around - plus some of the regulators that do it (malpassi somes to mind) are absolute shite.

[Cuzzo]

have you checked the factory ecu for leaking caps?

[-=DV=-]

the old ecu did have leaky caps, they were replaced about 3 months ago. I didnt bother checking the ecu that I replaced it to test with though. It does the same with both ecu's regardless.

[JP]

so the ECU isn't logging any fault codes?

[Duk]

Are you using the Greddy MAP sensor and using that as the load sensor input for mapping and clamping the output of the factory MAP sensor so it doesn't hit, eh hem, 'fuel cut' ?

[-=DV=-]

JP the ecu is logging no fault codes whatsoever.

Duk I am using the stock toyota map sensor for input and I am clamping the output so it doesnt hit fuel cut. On the old engine it ran fine with the output clamped at 4v....To try and figure out this problem I have even tried setting the clamp as low as 1v and no difference.

[RAAAH23]

have you tried burning it? or even threatening it with some sort of fire? lol >.>

[-=DV=-]

I have tried asking it nicely

I have tried requesting its cooperation in a calm but stern voice, warning it of the consequences of fire if it wont cooperate

I have tried straight out threatening it

I have tried yelling at it.

I have even tried fetching a jerry can of fuel and a lighter and placing it on the ground next to it before asking it to play nice and proceeding to try to work out the problem.

It doesnt seem phased by the threat of fire or being parted out, or crushed, or even donated to a wreckery. And it knows damnwell its being too difficult to even be a paddock basher at the moment.....It seems to really have me by the short and curlys

[greg]

i had a similar problem with my wifes vectra , tried everything changed cam and crank sensors as it was logging faults.nothing worked and the problem was intermittant everything checked out and vehicle went fine untill it started to miss and then stop,ten minutes later it would start and run perfectly.it finally cooperated and showed up when we had a meter on it .the internal regulator was faulty and would go haywire and alternate charge rate from 9volts through to16 which caused the ecu to throw up non existing faults untill it gave up and shut down .dealers said they had not had any similar problems but the distributor of the regulators was out of stock and had back orders mostly from holden dealers.
i wish you luck, these things are bloody annoying.
cheers greg