Author Topic: Just can't get it to start.... (now running)  (Read 12196 times)

Offline se7ensport

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Just can't get it to start.... (now running)
« on: August 25, 2008, 04:02:53 pm »
Hi guys

Been trying to get TB's running on pinto for a while without success.
I'm running GSXR750 tbs (4 x 240cc (this may not be correct, they are from a K4 2004, I'm trying to confirm without much success)) on a tuned pinto 2.0, I've been using the VEMS for ignition only with bike carbs and it worked really well.

Spark map is fine as I ran on carbs for ages (restarted it on carbs earlier to test and it fired straight up), I just can't get it to start and would appreciate if someone could review my settings.

It's close to trying to start but as soon as the starter motor is off it dies immediately.



my file is here http://www.box.net/shared/ipadnkqzsu



Cheers

Alex ;D
« Last Edit: September 05, 2008, 08:19:25 pm by se7ensport »

Offline rob@vems.co.uk

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Re: Just can't get it to start....
« Reply #1 on: August 25, 2008, 04:32:02 pm »
I'm betting that you're flooding it... My rules of thumb are:
cold start at Req_fuel if your firing all banks while cranking (Injection Settings bottom box)
Or cold start = 2.4* req_fuel and warm = 0.75 * req_fuel if running on alternate.

If it catches then dies then you're wanting to increase your afterstart enrichment AND/OR your cold start enrichment.

Set your Inj open time and effective ramp up time to 0, your batt fac might need to be closer to 650 or above, and the afterstart duration should be up over 1500.

As with all things your plugs will tell you the truth - pull them and check the state, I'm betting they're wet

Offline se7ensport

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Re: Just can't get it to start....
« Reply #2 on: August 25, 2008, 04:39:24 pm »
thanks Rob, just pulled plugs & they are dripping!

Will change settings & see what happens.

Offline se7ensport

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Re: Just can't get it to start....
« Reply #3 on: August 25, 2008, 06:51:56 pm »
Still no joy in getting it to start, it's close, but just not happening, I've put a clip on youtube:

http://www.youtube.com/watch?v=XC3cko3RYB0

my file is here: http://www.box.net/shared/9x1db4ct6a




Got the battery on charge again as it's taken a bit of a hammering today, any suggestions on changes to get it going appreciated.

Cheers

Alex

ps still trying to confirm exact flow rate of injectors.


Offline rob@vems.co.uk

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Re: Just can't get it to start....
« Reply #4 on: August 25, 2008, 07:22:42 pm »
I've just had the same happen with mine today, it started fine this morning, this afternoon it was rubbish.
Once you've flooded the engine as badly as that you have to pull the plugs and let the engine vent itself - as well as giving the plugs a good clean.

If you open the throttle more than 50% you get a fuel cut, start cranking the car with the throttle open, then occasionally let off to get the cranking injection happening, this gets fuel into the engine in a controlled amount e.g. if you want half the fuel, pulse the throttle so its open 50% of the time.

Offline gunni

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Re: Just can't get it to start....
« Reply #5 on: August 26, 2008, 01:40:14 am »
What are the injectors part numbers.

do you have a log of the cranking and attempting to start?

I´ll bet they are bigger then 240´s

Offline se7ensport

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Re: Just can't get it to start....
« Reply #6 on: August 26, 2008, 12:56:13 pm »
Hi Gunni

The injectors are from a 2004 K4 GSXR 750, they are orange and the part number on the side of them is 25003ZG, I haven't been able to confirm flow rate on them.


I don't have a log of attempted starting, will take one next time i have a play with it which will now be Wednesday evening.


Cheers

Alex

Offline se7ensport

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Re: Just can't get it to start....
« Reply #7 on: August 30, 2008, 03:46:37 pm »
GETTING THERE :)

got it to run for a short while (i did cheat a bit and got it up to temp on carbs then swapped it over).

It keeps dying after 30 sec or so, i've uploaded the datalog & my settings, as I'm sure it's rich by smell & plugs but it doesn't seem to make it on to the VE table, I think its just running on the priming & crank info....

http://www.box.net/shared/81xq9bna9k

http://www.box.net/shared/30ouhylifc

It must be something simple now, any clues?


ps if i touch the throttle it kills it quicker.

pps I recalculated required fuel as I've upped the fuel pressure as I wasn't confident they'd flow enough, in doing it I halfed the value for the basic settings and doubed the VE Table so that I'd have better control.




« Last Edit: August 30, 2008, 05:02:04 pm by se7ensport »

Offline rob@vems.co.uk

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Re: Just can't get it to start.... (getting closer...)
« Reply #8 on: August 30, 2008, 05:16:48 pm »
Your cold cranking and hot are the same - thats not really the way ahead! 
One way that I've used to find the ideal idle PW is to set the cranking theshold to around 2000rpm
then once the engine is running, adjusting the warm cranking value to get smaller pw values and making a note of where the engine seems happy as it warms up, eventually when you're at normal operating temperature you'll be able to tune by ear for a smooth idle. 
Then you'll have the PW you want at warm idle - with this you'll be able to work out the values down at the bottom left hand corner of the map as a rough estimate is PW is the %age in the current cell of the Req_fuel.  So if your idle PW is 2.1ms you'd be wanting a value of around 38%

Offline se7ensport

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Re: Just can't get it to start.... (getting closer...)
« Reply #9 on: August 30, 2008, 07:29:44 pm »
Thanks Rob, really appreciate the guidance, looking forward to getting it running smoothly.

Agree about the hot & cold cranking, it was purely an interim measure to get it to start, I set them the same and approached it by changing the engine temp by using carbs to warm it up (i was going in circles otherwise without success).


Offline se7ensport

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Re: Just can't get it to start.... (getting closer...)
« Reply #10 on: September 02, 2008, 10:39:28 pm »
Hi

Got the cold cranking set to 5.0, warm crank set to 1.9 on all banks and the threshold set to 2000. I got to these figures after it had been running for a while, this gave me a Lambda of about .90, it will now keep running on cranking so getting there bit by bit.

I followed Robs advice and tried the 1.9 as a % of the Req fuel figure which is 6.0, so I put 33 in the VE Table and it refuses to keep running if i lower the cranking threshold, I also tried variations around the figure of 33 but without success.

The injector settings are Divider 1, Alternate banks from h[0] 3..0 (this should be sequential).

Should the VE figure actually be 4 times as large as the cranking is all cylinders and the injectors are set to sequential?

Looking through my log the Gwarm jumps from 100 to 144 just before it stalls each time, could it be related?

Ran out of time again tonight  >:(
« Last Edit: September 02, 2008, 10:56:07 pm by se7ensport »

Offline rob@vems.co.uk

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Re: Just can't get it to start.... (getting closer...)
« Reply #11 on: September 03, 2008, 11:26:54 am »
What PW was showing on the main screen when you were running with the threshold set to 2000?
When the ECU moves from cranking to running there are two things you need to address - afterstart enrichment and then the warm-up enrichments. These scale the value that is being calculated from the VE table.  So the idea is to gradually reduce the PW from the rich cranking value to the stoichometric idle value in a gradual manner.   I bet you'd see the PW value drop down quickly as the engine stalls.

If its any concillation, I'm still messing around with my cranking and starting, settings and have been for ages.  The easy way was to have the mixture very rich - but that killed warm starting, I'm about 50% of the way there now.

Rob

Offline se7ensport

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Re: Just can't get it to start.... (getting closer...)
« Reply #12 on: September 03, 2008, 04:26:56 pm »
The PW on screen was showing 1.9 when I got the engine up to an operating temp of approx 80 degrees, with lambda mid 0.90’s.

As I’m firing on all banks at cranking and have the injectors set to sequential what value would I want the VE table x req fuel to be, Is it 4 x 1.9?

I’ve looked through my logs and the only value that seems to change prior to stalling is the Gwarm value- I don’t know what this relates to.


Offline rob@vems.co.uk

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Re: Just can't get it to start.... (getting closer...)
« Reply #13 on: September 03, 2008, 09:14:17 pm »
As you're firing on all banks you're injecting 4 times as much so your value sounds right.
Try it on alternate and start increasing the cranking PWs 2ms on the cold for 1ms on the hot, and see when the engine starts to catch, this should give you some real data.

Gwarm is the warm-up enrichment value.

Offline se7ensport

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Re: Just can't get it to start.... (getting closer...)
« Reply #14 on: September 04, 2008, 12:34:37 pm »

Haven't had a chance to get back out and test anything yet, but do have a question regarding warmup enrichment.

Why would my log show the value of enrichment jump from 100 to 144 if the coolant temp is above 71 degrees?

The figure of 144 is the equivalent of approx zero as I'm using 150 @ -6.6 and 140 @ 4.4.