Flex fuel or gas?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Wylie_Tahoe

Full Access Member
Joined
Nov 5, 2018
Posts
169
Reaction score
154
Have you confirmed a VIN match on at least 2 other locations on the truck? Like dash and door match and dash and frame match, etc?
 
Last edited:

iamdub

Full Access Member
Joined
Apr 23, 2016
Posts
20,712
Reaction score
44,433
Location
Li'l Weezyana
So, if that pump has worked previously, I should be okay with the same as a replacement, right?

That leaves me with my original question. Is there a way to tell, by looking at the engine, if it’s flex or gas? Because I think it has been changed. It’s in too good of shape to be original, I’m thinking.

The engines themselves are all the same and I'm pretty sure the only difference between FF and non-FF are the injectors. I don't think the manifold nor the fuel rails are any different since using FF injectors on a non-FF engine for performance purposes (nitrous, boost, big cam, etc.) is a common swap. The injectors do look different. Their electrical connectors are different as well.

FF injector:

832-11182_01__ra_p.jpg

Gasoline-only injector:

832-11180_01__ra_p.jpg
 

mattbta

Full Access Member
Joined
Jun 19, 2012
Posts
1,037
Reaction score
1,843
Location
Frisco, TX
What year? Does it have an inline fuel filter, underneath the driver door area? At some point in the vintage, only the Flex Fuel motors got serviceable fuel filters.
 

Wylie_Tahoe

Full Access Member
Joined
Nov 5, 2018
Posts
169
Reaction score
154
Based on the VIN the OP posted, its an 03. My 03 F/F has an inline fuel filter canister
 

Fless

Staff member
Super Moderator
Joined
Apr 2, 2017
Posts
10,246
Reaction score
20,306
Location
Elev 5,280
The OE fuel filter will most likely still be there even if the engine was replaced with a non-Flex engine. Doesn't really tell the story. The fuel injectors will.
 

OR VietVet

Multnomah Falls
Supporting Member
Military
Joined
Oct 8, 2014
Posts
19,069
Reaction score
31,172
Location
Willamette Valley
Some here will not agree but I always install a new fuel pump relay when I do an electric pump replacement. It all stems from a story from when I was running shops years ago.
 

Forum statistics

Threads
128,790
Posts
1,805,507
Members
91,773
Latest member
wbhidalgo17
Top