Car doesn't start and then after cooled down, starts
 

So go into store, come back out, car isn't starting.


Turns over, acts like it isn't getting fuel (starts up, gets to about 500rpms and then dies).

I call a tow truck to get it home and right as the tow truck comes, car starts right up and works fine. Car drives fine all the way home. Had my buddy check fuel pressure from the fuel pump and its great.

Heres some thoughts I had... tach signal comes from the coils correct? Well when my car gets really warm (<200 clt) after driving around for a bit, the tach dies. Just doesn't work. This has only happened since turbo'ing the car. Could heat coming off the mani & turbo be cooking something inside? What else would cause this?

¿que?

Are you running a MS?

yeah, put your mods in your sig newb. :p

cranking enrichment is probably incorrect when it's warm.

Are you on the stock ecu?!

Whoops, megasquirt 94/95


And guess what, the car cranks fine when warm, sometimes. Hence why I am feeling it isn't actual ms cranking settings. I'll attach my msq anyways.

tune your clt-based air density correction table. under advanced set it for AIT corrections.

I dont understand completely, can you expound on this a bit? Namely I can see the settings, but I dont understand what I would modify for what. What settings do you use?

My car did the same thing today, I go into a bar, come out drunk. Car doesn't start. I wait about 20 min, car still isn't starting. Tow truck takes me home (free via AAA).

I get home and for shits and giggles, I try to start. Car starts immediately. I drive it around a bit. Turn it off and it wont turn on again. Fucking hell project cars are a headache.

p.s. teach me how to tune my clt based density bit.

Coil pack or CAS.

/thread.

Pat I think you're wrong on this one.


Your car is heatsoaking and you're not correcting for it. You need to add fuel with your AIT-based air density corrections table (which is completely zeroed out on your msq). do a quick search, this is a heavily covered topic.

I didn't even look at his msq. So yeah if he's got some corrections that are wrong, fix em. But if it flat out refuses to fire when hot that's a leaky coil in some form or fashion, be it the coil pack or the CAS. If he had a timing light he could check for spark when this happens. Also could datalog it or just look in megatune to see if he's getting a RPM reading when the event happens.

Alright, thanks guys.

This makes sense because weather has been particularly warm. However today, the car was literally refusing to fire at all and this is after the car had sat for quite a while.

Was this after it ran for a while? Where's your AIT sensor and what were your AITs?

pm scott your email so he can send you an example MSQ file for to to look at for settings
i would help but i lost all my shit when my HD died

or i could just post this:

This was after the car had been sitting for <2hrs.

IAT is just bellow tb. I didnt have my laptop to take a datalog/look at AITs. I will do this tomorrow so I can check it out.

It just doesn't make sense to me why under the same circumstances it will start sometimes and sometimes not. Literally the same circumstances/coolant temps/ambient temps.

I'll try imputing similar values to yours B.

Tell-tale signs of a leaky coil. They go open when they get hot, usually right after shutdown, and they usually go back to working at some point when they're cooling down. Always works when cold though. Will test fine when cold because the problem only happens when it's hot. Anyways, try brain's settings but if it's still fucked, find out if MS sees RPM when this happens. If it does, coilpack.

Thanks man.

I need a few classes on DIY vehicle diagnosis. I suck at this.