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MSQ help anyone? Won't start hot.

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Old Aug 17, 2010 | 08:24 AM
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Default MSQ help anyone? Won't start hot.

I have my car starting fine from cold but once switched off and warm I can't get it going again?

It catches but just dies. I've hopefully attached my MSQ if anyone could point out the glaringly obvious that I must have missed.

Thanks
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File Type: msq
2010-08-17_12.38.14.msq (36.3 KB, 155 views)

Last edited by j555pre; Aug 17, 2010 at 08:35 AM.
Old Aug 17, 2010 | 08:37 AM
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Your cranking settings at 160*F ramp right up to 8.0ms compared with your setting at 130*F which is 3.6ms!?

Fix this by trying 2.5ms at 160*F

Also your WUE has a HUGE spike in it at ~130*F adding in 32% more fuel. Try reducing this figure to ~105%.
Old Aug 17, 2010 | 08:48 AM
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Thanks for that.

I've altered those and will try it again and get back to you.
Old Aug 17, 2010 | 10:05 AM
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Still no joy. Attached is a pic of a log I took whilst trying to start it.
Attached Thumbnails MSQ help anyone? Won't start hot.-log1.png  
Old Aug 17, 2010 | 10:35 AM
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What do your plugs look like?
Old Aug 17, 2010 | 10:42 AM
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Sooty, I cleaned them up before I tried the new settings.
Old Aug 17, 2010 | 10:56 AM
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Caveat: I have no experience with MS, but from my experience tuning the Hydra:

I get the sense that your warm-up enrichments are way too rich, and that they are overcompensating for your cranking enrichments when the car is cold. When the car is hot, your warm-up enrichments are not there, and although you will have cranking enrichment, it's not enough. Try unplugging your coolant temp sender before a hot start. If you still have it on the front water neck, it should be easy to get to. If this works, then scale back your warm-up enrichments, and increase cranking enrichment.
Old Aug 17, 2010 | 11:45 AM
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Thanks for the advice. Unhooked the temp sensor but still a no go.

I'll have another look at the settings when its cool and I can get it to run. I'll try and remember to log it running as well.
Old Aug 17, 2010 | 01:21 PM
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Do you think putting the old tan top injectors back in and see if I can get it starting on these? I just wonder if the 420cc's are leaking and flooding?

Clutching at straws I'll try anything!
Old Aug 17, 2010 | 03:50 PM
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Well I just had the car running again and it ran well up to 195 F. Then cut out and wouldn't start. The cars temp gauge was just about on half at this point. Is this about right?

Any more ideas anyone? My MSQ is above in the thread and attached below is a log when the motor cut out. Cheers
Attached Thumbnails MSQ help anyone? Won't start hot.-graph2.png  
Old Aug 17, 2010 | 06:45 PM
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It would help to display the AFR on the log to determine what your fuelling was like when it stalled.
Old Aug 18, 2010 | 01:10 PM
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I'll try and get a log done tonight.
Old Aug 18, 2010 | 03:30 PM
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Ok, car started fine and ran ok. AFR was fairly constant but fairly rich. Then something happened when warm and the car suddenly goes super lean (18+) and stalls. I'm thinking could this be the IAC valve suddenly opening fully and allowing far too much air in? Or is this the temp at which a setting changes? Really at a loss at the moment. Logs attached running to stall first and then trying to start.
Attached Thumbnails MSQ help anyone? Won't start hot.-graph-trying-stall.png   MSQ help anyone? Won't start hot.-graph-trying-start.png  
Old Aug 19, 2010 | 01:13 PM
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So does anyone have any ideas for this? Could it mechanical such as IAC? What if I disconnect it and see what happens? That might be tonights job.
Old Aug 19, 2010 | 03:47 PM
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Ok. I tried it again tonight but with the IAC valve unplugged. SAme thing happened. No idea what to do next.
Old Aug 19, 2010 | 05:52 PM
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upload your msq now that the car starts hot and i'll take a look at it
Old Aug 19, 2010 | 07:37 PM
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I am having the same issue. How do you have your cranking RPM and cranking spark advance set?
Old Aug 20, 2010 | 02:36 AM
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Originally Posted by N3v
upload your msq now that the car starts hot and i'll take a look at it
Thanks but it still doesn't start when hot. Also after warm up it just flicks from AFR 11ish to 18 super lean dies and won't start again.

I'm wondering if its something in my msq or whether its IAC related as it must be getting a whole bunch of air from somewhere or last night whilst asleep I wondered if my fuel tank could be vacuuming and stopping fuel getting through after the car has run a while.

attached is current msq thanks.
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File Type: msq
CurrentTune.msq (36.3 KB, 145 views)
Old Aug 21, 2010 | 01:27 PM
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So I tried it with the idle valve unplugged which should keep it shut but the car wouldn't start at all. Plugged it back in and it ran. Then cut out when hot and wouldn't run again! Grrrrrrrr!
Old Aug 30, 2010 | 05:22 PM
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Ok, changed the fuel filter, no difference. Idle valve disconnected still runs then cuts out. Tank is not vacuuming. So I'm thinking fuel pump or FPR any thoughts or other ideas?

Help!



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