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Anyone using xtau on a tpi'ed 350?

Posted: Fri May 23, 2008 9:20 am
by jimchristiansen
I wondering if my stalling at cold start could be cured by using the xtau options?

Is anyone here using it on their chevy 350?

I'm using a lumpyish cam in my 350, stock 350 injectors, ms2 2.88, contolled iac (mostly working I think :)

Thanks, Jim

Re: Anyone using xtau on a tpi'ed 350?

Posted: Sat May 24, 2008 7:13 am
by jimchristiansen
Reading the manual- it's all Greek to me :yeah!:

Re: Anyone using xtau on a tpi'ed 350?

Posted: Sat May 24, 2008 3:00 pm
by grippo
X-tau as it is presently implemented is only for acceleration/ deceleration, it can not be used for warmup - do not try. Even if it were, it is much more difficult to understand than normal warmup. However there are all sorts of things to try to get warmup to work.

If it stalls, is it immediately after you are finished cranking. If so then increase or decrease the After start enrichment depending on whether you smell raw fuel or not, or if the plugs are wet or not. If it runs ok for a while then stalls, look at the coolant temperature at which it stalls and increase or decrease the enrichment at that point. If it just needs a little more throttle to keep going, decrease the idle air steps at that temperature. Make sure your timing with a timing light matches the gauge in MT. Then try a little more/ less advance. There is nothing complicated about this, but you have to understand engine basics.

Re: Anyone using xtau on a tpi'ed 350?

Posted: Sat May 24, 2008 3:25 pm
by jimchristiansen
Thank you for the advice, Al.

My engine stalls after running for 10 seconds or so. I have been changing the IAC steps but hadn't considered changing the enrichment at a given coolant temp. I had just turned the xtau off after not finding that the default setup didn't seem to make any useful improvement to my troubles (although I think it may have contributed to my first flooded engine!) just before picking up your reply.

I'll give your suggestion of changing the enrichment at a given coolant temp a go. I'm getting pretty close to posting another Megasquirt Success! :yeah!:

Thanks again, Jim