I have a wierd starting issue with my turbo d16. when it's cold out under 50 degrees outside temp the car starts no problem and runs perfect,but when it's over 50 degrees outside temp i turn the key to on and the cel stays on the car will crank over run for a sec and die. I replaced the main relay thinking it was that but no change. I got the car in trade so I don't know much of what is done to it but as far as electronics i know of is neptune rtp/p28 ecu obd2-obd1 harness,gm 3 bar map sensor,aem wideband. I can't find the plug to jump to get the codes either.

 

anyone?

 

u check fuel pressure?