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Author Topic: Slight throttle cut high rpm  (Read 24333 times)
nyet
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« Reply #30 on: November 14, 2014, 10:33:12 AM »

How does the ignition timing look to you? Are those oscillations acceptable in your opinion?

No. Definitely not good IMO

I think some kind of noise is being picked up and ending up in your load signal... which is odd, since load is basically MAF/RPM, and both your MAF and RPM look good.

Perhaps there is some filtering of both that I dont know of in ME that the load calc doesn't get.

You mentioned before unplugging your MAF made it go away, I suspect a bad ground or wiring to the MAF, or a dying sensor?
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spacey3
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« Reply #31 on: November 14, 2014, 12:59:35 PM »

Thanks for your thoughts Nyet.

Hmm, the car in general runs pretty well, but there is this 'hiccup' issue.

The wires should be good, I went over everything like that yesterday. Also cleaned the maf but nothing changed so it's not simply dirty.

Fingers crossed it's a silly bad earth or something. I've also got another ecu in the garage so if I don't find anything up with the earths I'll try that too.
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nyet
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« Reply #32 on: November 14, 2014, 01:43:18 PM »

Hmm, the car in general runs pretty well, but there is this 'hiccup' issue.

I have to be honest, at first I thought you were being overly paranoid, but I have to say I think it would be a good idea to get to the bottom of this... Forget for a moment about the throttle and ignition swings.. having your actual load move around like that a lot is not a good thing for ME7....

Not to scare you or anything, but I think it is worth trying to fix.
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« Reply #33 on: November 14, 2014, 02:56:07 PM »

Forget for a moment about the throttle and ignition swings.. having your actual load move around like that a lot is not a good thing for ME7....

I think that will most likely be the root cause of the throttle/ignition oscillations, hmmm. Got a busy weekend coming up I feel!
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nyet
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« Reply #34 on: November 14, 2014, 03:07:05 PM »

Shot in the dark: can you log your ambient pressure?

Also, do you have a spare ECU you can try?
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spacey3
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« Reply #35 on: November 14, 2014, 03:19:41 PM »

Shot in the dark: can you log your ambient pressure?

Also, do you have a spare ECU you can try?

Sure, I'll be able to take the car for some runs tomorrow day so will grab it then. Is there anything else I should add to look at in particular?

Which one is ambient pressure? pu_w or pus_w?

Also yes I do have another ECU spare, so I'll give that one a bash also. Rules it out if nothing else.
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spacey3
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« Reply #36 on: November 15, 2014, 07:39:32 AM »

Ok so been fiddling with the car today, checked all MAF, MAP and earth wires, all look good.

Here's another log with all of the throttle sensors and ambient pressure.

Nothing's changing so I'm going to get my spare ECU fitted now and see what it does then.
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spacey3
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« Reply #37 on: November 15, 2014, 08:55:43 AM »

Here's a log from the other ecu, it's in standard form, but there's still some throttle intervention up top.

It's looking like a hardware issue somewhere I think, maybe time for a new MAF.
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spacey3
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« Reply #38 on: November 17, 2014, 08:36:27 AM »

Picking up a new MAF tonight, at £100 I'm hoping it'll be resolved after that!

My max MAF readings are ~200/210 so I'm thinking it maybe under reading a little anyway (signs of a dying sensor). Most of the guys with similar mods to me are seeing circa 220.

Will update later.
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ddillenger
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« Reply #39 on: November 17, 2014, 04:10:30 PM »

Picking up a new MAF tonight, at £100 I'm hoping it'll be resolved after that!

My max MAF readings are ~200/210 so I'm thinking it maybe under reading a little anyway (signs of a dying sensor). Most of the guys with similar mods to me are seeing circa 220.

Will update later.

0 percent WGDC.
17psi boost at redline.

What's going on there?
Ignition angle looks normal to me (for a slow car with a shitload of samples).
Your AFR on the other hand......What's going on there?

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spacey3
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« Reply #40 on: November 17, 2014, 05:55:17 PM »

Well the MAF has made a large difference, general throttle response is much better, but my boost has moved to lower than requested (previously it was a little more), also I saw very minimal throttle oscillations.

0 percent WGDC.
17psi boost at redline.

What's going on there?
[/quote}

Hmm... I think you've downloaded the standard ecu file log... I would have thought it's going way over due to the hardware mods.


Ignition angle looks normal to me (for a slow car with a shitload of samples).
Your AFR on the other hand......What's going on there?



Thanks for the compliment...

The AFR is in the low 12's, no good in your opinion? Or are you referring to oscillations?
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ddillenger
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« Reply #41 on: November 17, 2014, 06:02:20 PM »

I was looking at your standard ecu log.
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spacey3
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« Reply #42 on: November 21, 2014, 03:03:41 AM »

For anyone interested, changing the MAF has solved this, it must have been dying as my max g/s readings went up from ~200 to 210, oddly my actual boost moved around a lot so I've had to re-adjust for it but the car is running much better in itself. The throttle response has change dramatically at part load.

I still have some very slight reduced requested throttle angle sometimes but this is ~6.5k rpm and is ~1/2% max so I don't think this is anything to worry about really, it's almost at the limiter up there and will hardly ever be driven that high so will just keep an eye on it.

Thanks to all who helped out on this one!
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