My 4.3 has 150k and has always started in the first click. About a week ago it started needing to be cranked for 4 to 10 seconds before it will start and it runs rough for a few seconds after starting. I have not done any tests yet and was looking for some pointers on what should be checked and if there is any order to the testing.

 

Start with a fuel leakdown test. You can find instructions on the last post of this thread https://blazerforum.com/forum/2nd-ge...art-now-75761/

 

ROCKP2: Thanks for the quick response.

I rented a fuel tester from Autozone. What a great store. They took a deposit of $150 but upon return I get a full refund. FREE works for me.

Round 1: I attached the pressure gauge to the fuel rail. On the 99 4.3V it sits just forward an to the right of the distributor cap.
Engine cold. Turn ignition without starting. Pressure jumped instantly to 54 lbs. Start engine, good quick start and pressure at 54. Turn off ignition, pressure jumped to 62 lbs and then back to 54.

Just to see if results I turned ignition off and on three times. Each time the pressure was good and the engine started quickly. This was not consistant with original problem of "hard starting".

However!
Rechecked gauge after 10 minutes and it had dropped to 22 lbs.

Round 2: Turned ignition without starting. Pressure jumped to 54. Engine took several revolutions before starting very rough and then leveled out. Turned off ignition, pressure jumped and leveled as it did in round 1.

Same results each time I did this series of start/stop.

Can I rule out a fuel pressure problem?
Many Thanks!
BG

 

Bill,
Apologize for just seeing your results. Haven't been at my puter for the last couple of days. Based off what I have learned on this forum...No you cannot rule out a fuel pressure problem. It sound like you have a problem. When you turn the key On (don't start engine) the lowest it can be is 60lbs while the fuel pump is running. Once the fuel pump shuts itself off the pressure must remain no lower than 55lbs for ten minutes. Below is another link. On the third page, Captain Hook goes into some more detail as far as checking the fuel pump itself, etc. I have learned this procedure from just reading the forums. Look for posts from Captain Hook. He is constantly addressing this problem and knows these vehicles inside and out. I know you state yours starts fine in the cold, but the below thread gets into addressing fuel pressure...cold or warm.

https://blazerforum.com/forum/2nd-ge...rt-cold-75428/