GM Truck Club Forum banner

1 - 2 of 2 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1
I just wanted to post this fix,

I have a 5.7 it was sitting for a while, couple of years maybe, and the poppets were certainly gummy.
It was hesitating off the line and would sometimes back fire. Lean codes on both banks and rich exhaust at idle.

I replaced the TPS - it was mossy and falling apart
I upgraded from SCPI to the MFI injectors- poppets are junk anyway but mine were a mess from sitting so long.

SUPER SMOOTH - huge difference, Worth every penny and it's a 2 hour job, so not that bad!

I have had these poppets in many other trucks but I put a huge amount of mileage on my trucks or put a lot of gas through them, so they never gave me problems.

I've been told if they sit they can become problematic, they stick... too much gas on idle-Rich and too little on WOT-lean
I guess they stay open too much when idling and just the opposite they won't open enough on WOT so I was getting a rich fuel smell on idle and a lean code on both banks after a highway run and The hesitation popping and backfiring.

The big question!!!

Do the new injectors require the same fuel pressure and will this help resolve the B.S. with the fuel pumps?
 

·
Registered
Joined
·
7,979 Posts
Yes they take the same pressure and no it wont repair the problems with the pumps since alot of the issues with the pumps is a poor design and the wiring is to small.
 
1 - 2 of 2 Posts
Top