LLY: Injector Numero 7

lts1ow

Needs moar PAH!
May 14, 2012
1,598
0
36
NJ
CTS monitor says its floating +/- 8.4 compared to the rest at under +/-3, that combined with a small hit in fuel mileage leads me to think its on its way out.

Not planning on going larger than stock so what is the best OEM replacement injector these days and is it crazy to only replace one?
 

Toxic

Member
Dec 30, 2015
55
1
8
30
Mansfield, OH
Check it tomorrow. Mine is 5+ one day then 1 the next. Same injector for me also. I bought a replacement from LDS and in 3 months it was consistently over 4 in park, Got it replaced under warranty and now this one seems to be slowly working its way back up. In the spring I'm gonna do a return rate test as I think its another injector that's causing it. Not once have I had any symptoms though that it was bad other than a high balance rate.
 

lts1ow

Needs moar PAH!
May 14, 2012
1,598
0
36
NJ
I have been checking it rather often, doesn't get any better. Wish I could attribute the MPG hit to winter fuel but IDK if thats to much of a stretch. Other than balance rate, nothing is out of ordinary.
 

SickLL7Crenshaw

Billy The Kid
Mar 10, 2013
1,088
34
48
31
Mexico
CTS monitor says its floating +/- 8.4 compared to the rest at under +/-3, that combined with a small hit in fuel mileage leads me to think its on its way out.

Not planning on going larger than stock so what is the best OEM replacement injector these days and is it crazy to only replace one?

Have you tried ice picking that injector connector? Or considered upgrading to the 90 degree connector? If you know it's not the connector then there are several people that sale stock Bosch reman LLY injectors. LDS sales them just north of $300. It's up to you whether you wanna replace all 8. If there all in spec the only other thing is I'd recommend you checking the return rates before spending the coin on 7 more.
 

lts1ow

Needs moar PAH!
May 14, 2012
1,598
0
36
NJ
AFAIK, I thought the ice pick trick only worked if you were having misfire and code thrown issues, not balance rate issues?
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,610
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Mid Michigan
Its an LLY and #7. Have you checked the wiring from the FICM to it yet?

EDIT: didnt read far enough forward. Someone beat me to it.
 

lts1ow

Needs moar PAH!
May 14, 2012
1,598
0
36
NJ
I plan on examining the number seven harness and attempting to ice pick it this weekend but again, wouldn't that show a more defined failure mode and not just high balance rates? (Not that I wouldn't love spending the $100 on a harness fix versus a new injector :D)
 

lts1ow

Needs moar PAH!
May 14, 2012
1,598
0
36
NJ
Just to toss in, FICM connector C1, pin 3 to pins 61/62 should be a circuit correct? (with injector being in the center of the two points)
 

Burn Down

Hotrodder
Sep 14, 2008
7,092
28
48
Boise Idaho
Matt,
loose connections can cause all kinds of issues and not pop codes. I would definitely re-route the harness (give it some slack so it's not pulling on the connectors as hard) on 2 and 7 and ice pick all of them... Make sure you put a protector on that harness at the ficm as well.
 

mechman3

no such thing as too fast
Jan 7, 2015
181
2
18
Saratoga Springs, Utah
Matt,
loose connections can cause all kinds of issues and not pop codes. I would definitely re-route the harness (give it some slack so it's not pulling on the connectors as hard) on 2 and 7 and ice pick all of them... Make sure you put a protector on that harness at the ficm as well.
not to hijack this thread but I am having issues my number 7 inject(code P0207 and P2146) When the codes come up, no rhyme or consistency, the injectors make noise. If I shut the truck off and restart it after a couple of minutes the codes are there but no issues. Then the CEL goes out as well. Where is the FICM and what do I check in the wiring harness? It does have the new connector on it for that injector.
 

Burn Down

Hotrodder
Sep 14, 2008
7,092
28
48
Boise Idaho
not to hijack this thread but I am having issues my number 7 inject(code P0207 and P2146) When the codes come up, no rhyme or consistency, the injectors make noise. If I shut the truck off and restart it after a couple of minutes the codes are there but no issues. Then the CEL goes out as well. Where is the FICM and what do I check in the wiring harness? It does have the new connector on it for that injector.

The ficm is the silver box on the right front valve cover of the engine.

Have you pulled the connector on 7? Verified it’s plugged in tight and the connector lock is engaged in the injector?

Also ck the wiring harness at the top of the ficm. The bracket that gm ties the harness to likes to rub the harness and short shit out.
 

mechman3

no such thing as too fast
Jan 7, 2015
181
2
18
Saratoga Springs, Utah
the ficm is the silver box on the right front valve cover of the engine.

Have you pulled the connector on 7? Verified it’s plugged in tight and the connector lock is engaged in the injector?

Also ck the wiring harness at the top of the ficm. The bracket that gm ties the harness to likes to rub the harness and short shit out.

thank you