A friends 2000 chevy pickup with a small V8 (not sure which one ) has to be spun over a long time (like 30 seconds or more) on a cold morning when the temp is below 40 degrees..it has had a new fuel pump and temp sensor installed,the pump was showing low oressure and was original so he replaced it--the temp sensor he just swapped another known good one , and this has not fixed the problem,it did the same thing still...
It will fire right up if its over 45 degrees or so..once it does start and is driven,it will fire up all day long instantly..all the fuel lines have been checked for any leaks and none are present,some were replaced also..if its cold the next morning,it will refuse to start unless he keeps cranking it either a long time or repeatedly..then it'll finally start and run ragged for a few seconds,then smooths out and runs fine..
The other day he even tried taking the computer off and brought it in the house overnight and installed it quckly just to see if it would start any faster,and it did not..he had a few other vehicles have faulty ECM's that did this so he figured he'd try that..no luck..
I'm not well versed in later trucks EFI systems or computers,all I could tell him was maybe it has some other sensor like an air temp sensor thats not working?..someone said there is a "priming" curcuit in the fuel pump that might not be working right--you can hear the fuel pump come on when you turn on the ignition as normal though..no codes show up on his scanner either...
Anyone have any clues?..I dont!..I told him if it had a carb I could probably fix it..
It will fire right up if its over 45 degrees or so..once it does start and is driven,it will fire up all day long instantly..all the fuel lines have been checked for any leaks and none are present,some were replaced also..if its cold the next morning,it will refuse to start unless he keeps cranking it either a long time or repeatedly..then it'll finally start and run ragged for a few seconds,then smooths out and runs fine..
The other day he even tried taking the computer off and brought it in the house overnight and installed it quckly just to see if it would start any faster,and it did not..he had a few other vehicles have faulty ECM's that did this so he figured he'd try that..no luck..
I'm not well versed in later trucks EFI systems or computers,all I could tell him was maybe it has some other sensor like an air temp sensor thats not working?..someone said there is a "priming" curcuit in the fuel pump that might not be working right--you can hear the fuel pump come on when you turn on the ignition as normal though..no codes show up on his scanner either...
Anyone have any clues?..I dont!..I told him if it had a carb I could probably fix it..
