Having some seriously bad cold start issues! at Wits end!

[Ryan Simmons]

Hi, basically it seems that the longer i leave the car sit , the worse the problem is. If i dont start the car for two weeks, then i am pretty certain it will not start without some serious messing about! Every day leading up to about two weeks -when its at its worse, it progressively gets harder and harder to start.

Anyway. basically, i flick on the ignition and allow the pump to prime. 40psi of fuel pressure is indicated in the rail on a dead head setup. Once prime has finished, i crank the engine. It will turn over and turn over without even a cough sometimes. once i give up turning over it usually backfires quite heavily. Looking at the plugs and they are all saturated with fuel. I then clean up the plugs, burn out the fuel from the bores and try cranking again. This time it will fire up ( but only whilst blipping the throttle) and run on 2~3 cylinders.  Pull the plugs again to find completely black charcoal plugs to the point where they will not spark properly hence the poor running.  Clean up the plugs and bores for a second time, re-install (note engine now has some heat) , turn the key and it fires up perfectly, all cylinders firing and idles fine!

If the car has only been sitting for a day or two, it will generally cough into life after about 8~10 rotations of cranking, however when it does fire the amount of fuel fumes chucked out of the exhaust is crazy it makes my clothes reak and the garage goes black with fuel smoke!

Once it has fired, if i blip the throttle it tends to want to bog down more than rev up. only slow progressive pressing on the throttle will allow it to rev up smoothly. also whilst its still cold, its very jerky to drive. Once the car has reached full running temp, it is smooth as silk and drives like a dream!and further inspection of plugs after a run show they are clean and of correct colour!

It would seem its over fuelling whilst cranking perhaps flooding the engine and causing the plugs not to fire..  But then again it could be the other way -not enough fuel on the pre-crank prime causing a non fire and upon the second cycle -more fuel is added making the mix very very rich?! i really don't know which way around it is!

I believe AFR once i got it started and running on all cyls was around 15~16. and iirc when i blip the throttle it went down to 10. ill have to confirm this tho.

One other thing i find is that when it does finally fire up and idle smoothly, after about 10 seconds it just dies. a quick restart gets it running fine again. this also happens if i start it 24 hours after its last drive, it generally coughs once or twice, springs in to life then dies 10 seconds later unless i keep it revving above 1800 rpm.

Heres some engine specs..

toyota 3s-gte rev3 4-pot 16v 2.14 L stroker

1200cc bosch top feed injectors

Dead head fuel rail setup, aeroquip lines, AN1000 regulator set to base 40psi

Bosch 044 external pump, custom tank pickup.

HTAGt3582r turbo setup.

570bhp( flywheel)/480 lbft.

Engine is mechanically sound.

I have attached the PCL file, please could you have a look and ammend anything you feel that may rectify the issue. Perhaps two maps that i could try one with a richer cold start and one leaner?

I hope you can find the answer to this as its been an issue for a long time now and after 7 years building the car, im starting to really hate it! 

Thanks

Ryan

may2013-pre-cold-start-alterations.pcl

[Simon]

I would try unplugging the injectors. Turn on the key and let pressure build. Crank engine and see if the plugs are wet.

Checking to see if the injectors could be leaking.

Next would be to turn the prime fuel off and see if it fires or if plugs are wet again.

Problem is going to be too much fuel.