Help! LT1 hard starting

[Towu4free]

well....tomorrow itll be going back for diagnoses ...ive had many people tell me that the coolant temp sensor will make funny things happen...but i dont believe it would have anything to do with the fuel pressure... im thinking next would be the fuel pressure regulator...im not sure if i mentioned this before but when its in gear sitting at a stop light or what have you it seems to feel rough like maybe its missing but i honestly can not tell im so anxious to fix this problem hopefully by the end of the week all will be well!! thanks for all your help

 

[John Robinson]

New idea

Nobody has suggested checking the throttle position sensor. It is an easy check and it could possible be the problem you are having. There are several posts about it that you can search for. Good Luck and keep us informed.

 

[Robertwav1]

My hard starting problem was the FPR. Take a wiff of vacuum source and see if you smell any residual fuel...you shouldn't, if you do, suspect the fuel pressure regulator...diaphragm leaks in time.

 

[gmjunkie]

well....tomorrow itll be going back for diagnoses ...ive had many people tell me that the coolant temp sensor will make funny things happen...but i dont believe it would have anything to do with the fuel pressure... im thinking next would be the fuel pressure regulator...im not sure if i mentioned this before but when its in gear sitting at a stop light or what have you it seems to feel rough like maybe its missing but i honestly can not tell im so anxious to fix this problem hopefully by the end of the week all will be well!! thanks for all your help

Well,You better believe that,THAT temp sensor in the water pump will cause weird things to happen!! It will make them Start Hard Cold,It will Make them START HARD Warm!! Just depends which part of it is bad!! It will make them Rich or it can cause them to run Lean!! It can cause them to run right part of the time, and run like SH*T part of the time!!

Just depending on whats happening,it could effect the fuel pressure regulator and it's operation!!

P.S. I'm no Electronics or Mechanical Engineer,But I have stayed at the "Holiday Inn Express" on several occasions!!

 

[Towu4free]

thanks for the help once again.. im searching as we speak on the TPS.. and one of your posts stated something about smelling fuel...when the car starts u can smell raw fuel and its coming out of the exhaust.....it goes in today for diagnoses....one more thing to throw out there...this morning i got in it and for the heck of it i turned the key on let the pressure build up and without mashing the pedal to the floor tried to start it...it started but when it did catch it seemed as if it went from 2-4-8 cylinders running...(rough to normal) idle....thank you all for your help its driving me insane!

 

[Towu4free]

Well NEW NEWS! i had it tested again today i have perfect fuel pressure at the rail but it drops off very fast...if i cycle the key on and off 7 times it will start right up...its bleeding off somewhere but i just cant find it...i suspect the fuel pump pulsator...either its bad or loose even? anyone know anything about those? thanks

 

[Towu4free]

Can i bypass the fuel pump pulsator? or no