I have the problem ( utec, rc 550cc injectors and 3.5 bar FPR ), I´m really tired of this issue , and the solution is get a EMS like Haltech , F-con , etc , or reflash the ecu for bigger injectors , or wait a little for the new UP-REV software......
The problem here is the cranking injectors time......

 

Sorry. I am running 550cc DW injectors with the HKS FCon iS. No hot start issues at all with that combo.

 

Bobby at Performance Race Engineering in Portland, OR

http://www.preracing.com/

 

Haltech, HKS 1000 cc injectors, hot starts were never a problem. Starts just like stock - immediately. Cold starts used to take 2 cranks (no gas required), with a little fine tuning, it only takes 1 but the first crank is not quite perfect yet (at about 1-2 seconds it starts to die a little, but then picks back up).

Haven't had a chance to play with it too much but I know there's a cold start enrichment that lets you adjust fuel at specified time intervals after cranking begins (offset % from base fuel table)... It's a little bit of a stab in the dark since you can't get an A/F reading until the O2 sensor warms up (15 seconds for me).

 

Raj, let me know about this stuff The HKS injectors are nice and don't give any problems when dialed in.

A little more prime pulse and cranking injector will make it start immediately. Then add a little fuel from 2-5 seconds after engine start in the 'post-start' fuel table.

 

How would a reflash fix this?? If this is true id send my ecu to uprev again for this!!

 

You need to reflash the ECU for bigger injectors , this would reduce the cranking injector times , and this would solve all that hot starts issues.

 

It's near perfect - not an issue at all. Thanks though - I don't want to waste your time with trivial stuff when you've got really cool stuff coming out that better deserves your attention.

 

+1 never an issue with my Utec and APS injectors on warm/hot starts. Still have the UTEC but now have DW 600 injectors and every now and then I have an issue with warm starts, but not a big deal.

 

So if we reflash the ECU for larger injectors, do we need to retune the utec as well or leave it as is?

 

You will need to change the values in the 0% column ( if you make a reflash for your 550cc injectors , the value would be 0 in that column ), the rest of the map doesn´t need any change , I assume that you are using the speed density mode.........

 

Jeremy at PF is my tuner, so I'll have to have him do it for me. I wish I knew how to do my own tunning. I'll just wait till I upgrade my pulley before I have the reflash and retune.

 

I had Precision 1000cc low imp injectors, V-Pro, NO reflash, and it still started up every single time, no problem.

I miss my car

 

If you end up going through with that you'll have to let me know how it goes. And if all a tuner will have to do is change the 0% column you would be able to do that yourself real easy. I assume you would just have to pull the ecu and send it out to be flashed. I would love to do that but not sure if I'm willing to pay the $400 or whatever it would be.

 

Im willing to pay 300 to 400 just waitin on a response from uprev..

 

Ok, got the flash from uprev.. Hot starts still require mashing the throttle...


I guess ill try the 0 in 0% column of utec..

 

I also have a UTEC with my APS TT kit and it starts really quick, hot or cold. In fact, it starts the same as when I had the Unichip. I'm still running the APS supplied injectors for now.

 

Do you have huge 750cc like me?? What is your fuel map looking like at the 0 column?

 

He says he has stock APS injectors so he wont have startup issues

You need to step up to a real EMS I have 1000cc injectors and cold and hot startups with the Fcon are fine

 

You should get a fcon and all your problems will be resolved!