Cylinders 3 and 5 running leaner than the rest. - LS1TECH - Camaro and Firebird Forum Discussion

Notices
Fueling & Injection Fuel Pumps | Injectors | Rails | Regulators | Tanks
Sponsored by:
Sponsored by:

Cylinders 3 and 5 running leaner than the rest.

 
Old 12-30-2018, 04:17 PM
  #1  
Launching!
Thread Starter
iTrader: (26)
 
98Zheadsncam's Avatar
 
Join Date: Jun 2011
Location: Colorado
Posts: 248
Default Cylinders 3 and 5 running leaner than the rest.

So, I've recently discovered an odd issue. I pulled the B8EFS spark plugs out the other day because I'm mostly street driving the car and figured I'd run BR7EF's as I can't run crazy boost on the street anyway. At any rate, I discovered that all the plugs EXCEPT cylinders 3 and 5 looked like they were running too rich. By this, I mean the insulator tips all the way to the tip of the electrode are dark. Cylinders 3 and 5 looked good...white insulator as far as I can see without cutting the plug. I swapped coils...no difference. On the logs, everything looks fine. No super rich areas of the VE. Motor runs great under boost...no issues there. I'm seeing this same pattern with the BR7's as well.

All the plug wires look fine...no burnt areas. Intake is a Vic. Jr.

Any ideas will be greatly appreciated.

Thanks guys.
98Zheadsncam is offline  
Old 12-30-2018, 06:43 PM
  #2  
TECH Senior Member
 
Join Date: Jun 2016
Location: Central Cal.
Posts: 9,362
Default

Clogged/dirty 3 and 5 injectors....
G Atsma is online now  
Old 12-30-2018, 06:52 PM
  #3  
TECH Fanatic
iTrader: (1)
 
Che70velle's Avatar
 
Join Date: Jan 2012
Location: Dawsonville Ga.
Posts: 1,897
Default

Originally Posted by G Atsma View Post
Clogged/dirty 3 and 5 injectors....
Agreed. Send your injectors off for a flow test and cleaning. And maybe do a compression/leak down test on the engine.
Che70velle is offline  
Old 12-30-2018, 09:51 PM
  #4  
TECH Junkie
iTrader: (40)
 
00pooterSS's Avatar
 
Join Date: Mar 2008
Location: Dallas
Posts: 3,325
Default

Did you measure the temps of the manifold/header primaries to see if those two are hotter?

You could also swap injectors 3&5 with 1&7 and see if the issue follows the injectors.

Could possible me a difference in compression or heat in those cylinders if the above doesn't show up anything.

But I would take it easy until you get it sorted, in case it has dirty injectors. Don't want it to pop while you're trying to figure it out.
00pooterSS is online now  
Old 12-31-2018, 06:49 AM
  #5  
Launching!
Thread Starter
iTrader: (26)
 
98Zheadsncam's Avatar
 
Join Date: Jun 2011
Location: Colorado
Posts: 248
Default

I'm running E85....been doing so for the past 4 years. The car sits most of the time...only 1500 miles on the motor since it was built back in 2015.

I need to get batteries for my temp gun. That's a good idea.

I'll probably just pull the injectors and have them cleaned.


Thanks guys.
98Zheadsncam is offline  
Old 01-02-2019, 08:35 PM
  #6  
TECH Senior Member
iTrader: (37)
 
LilJayV10's Avatar
 
Join Date: Apr 2007
Location: Evansville,IN
Posts: 7,000
Default

E85 and sitting most the time will cause lots of fuel system issues.
LilJayV10 is offline  
Old 01-03-2019, 07:08 AM
  #7  
Launching!
Thread Starter
iTrader: (26)
 
98Zheadsncam's Avatar
 
Join Date: Jun 2011
Location: Colorado
Posts: 248
Default

Just wanted to post an update. I pulled the injectors on Tuesday. Definitely found the problem.

Before.

After a dunk in some 87.


They're being cleaned today...I should have them back tomorrow. I'll be making a pump gas tune for the car.
98Zheadsncam is offline  
Old 01-03-2019, 10:00 AM
  #8  
TECH Senior Member
iTrader: (37)
 
LilJayV10's Avatar
 
Join Date: Apr 2007
Location: Evansville,IN
Posts: 7,000
Default

check your fuel filters..............
LilJayV10 is offline  
Old 01-03-2019, 10:11 AM
  #9  
Staging Lane
 
AUS Injection's Avatar
 
Join Date: Aug 2018
Posts: 85
Default

Don't let your motor sit that long without running! especially running E85 or meth
AUS Injection is online now  
Old 01-03-2019, 08:11 PM
  #10  
TECH Junkie
iTrader: (40)
 
00pooterSS's Avatar
 
Join Date: Mar 2008
Location: Dallas
Posts: 3,325
Default

Yuck that's pretty bad.

I had no idea e85 did that. Learned me something new.
00pooterSS is online now  
Old 01-03-2019, 08:35 PM
  #11  
TECH Senior Member
 
Join Date: Jun 2016
Location: Central Cal.
Posts: 9,362
Default

Originally Posted by 00pooterSS View Post
Yuck that's pretty bad.

I had no idea e85 did that. Learned me something new.
Yo, THAT is some NASTY crud! No wonder it was lean on those holes....
G Atsma is online now  
Old 01-04-2019, 05:47 AM
  #12  
Launching!
Thread Starter
iTrader: (26)
 
98Zheadsncam's Avatar
 
Join Date: Jun 2011
Location: Colorado
Posts: 248
Default

Originally Posted by AUS Injection View Post
Don't let your motor sit that long without running! especially running E85 or meth
I drive the car every other week. I figured that would be adequate.

From what I've found online, this gunk is supposedly from driving the car...the gunk forms when the injector drips after shut down, and it bakes in the radiant heat from cylinder. I'm no authority on the matter, though. Are you saying the pump E85 is just dirty?
98Zheadsncam is offline  
Old 01-04-2019, 05:48 AM
  #13  
Launching!
Thread Starter
iTrader: (26)
 
98Zheadsncam's Avatar
 
Join Date: Jun 2011
Location: Colorado
Posts: 248
Default

Originally Posted by G Atsma View Post
Yo, THAT is some NASTY crud! No wonder it was lean on those holes....

Yeah, surprisingly they all looked like that.
98Zheadsncam is offline  
Old 01-04-2019, 10:12 AM
  #14  
Staging Lane
 
AUS Injection's Avatar
 
Join Date: Aug 2018
Posts: 85
Default

Originally Posted by 98Zheadsncam View Post
I drive the car every other week. I figured that would be adequate.

From what I've found online, this gunk is supposedly from driving the car...the gunk forms when the injector drips after shut down, and it bakes in the radiant heat from cylinder. I'm no authority on the matter, though. Are you saying the pump E85 is just dirty?
How many miles do you put on it when you take if for a drive? or do you just drive it around the block
AUS Injection is online now  
Old 01-04-2019, 11:33 AM
  #15  
TECH Addict
 
Join Date: Mar 2013
Posts: 2,617
Default

Originally Posted by 98Zheadsncam View Post
I drive the car every other week. I figured that would be adequate.

From what I've found online, this gunk is supposedly from driving the car...the gunk forms when the injector drips after shut down, and it bakes in the radiant heat from cylinder. I'm no authority on the matter, though. Are you saying the pump E85 is just dirty?
Actually those injectors can be fouled from oil too. The oil from the valve guides and PCV system vaporizes in the intake when the engine heat soaks and bakes onto the injectors. You may find the valve seals are leaking on those cylinders or the valve guides are a little on the loose side OR if you have ported heads the rocker studs are leaking oil into those cylinders. This is very common on ALL engines not just HP stuff.

RockinWs6 is offline  
Old 01-06-2019, 09:05 AM
  #16  
Launching!
Thread Starter
iTrader: (26)
 
98Zheadsncam's Avatar
 
Join Date: Jun 2011
Location: Colorado
Posts: 248
Default

Originally Posted by AUS Injection View Post
How many miles do you put on it when you take if for a drive? or do you just drive it around the block

I have a set route I use when I take the car out. Some city driving, then I jump on the interstate. It's about 15 miles round trip.

Last edited by 98Zheadsncam; 01-06-2019 at 09:10 AM.
98Zheadsncam is offline  
Old 01-06-2019, 09:08 AM
  #17  
Launching!
Thread Starter
iTrader: (26)
 
98Zheadsncam's Avatar
 
Join Date: Jun 2011
Location: Colorado
Posts: 248
Default

Originally Posted by RockinWs6 View Post
Actually those injectors can be fouled from oil too. The oil from the valve guides and PCV system vaporizes in the intake when the engine heat soaks and bakes onto the injectors. You may find the valve seals are leaking on those cylinders or the valve guides are a little on the loose side OR if you have ported heads the rocker studs are leaking oil into those cylinders. This is very common on ALL engines not just HP stuff.
I vent the valve covers to the atmosphere, but the motor does have blow by from the large ring gap. There's also definitely oil getting past the valve stems...I noticed it on decel when the car was on the dyno. Checking the seals and guides probably isn't a bad idea.

Last edited by 98Zheadsncam; 01-06-2019 at 02:14 PM.
98Zheadsncam is offline  
Old 01-07-2019, 09:47 AM
  #18  
Staging Lane
 
Join Date: Sep 2016
Posts: 84
Default

So what's the update on this? Did you get them cleaned? Sorry if I missed the post some where.

If you have large gaps allowing excessive blow-by, consider a running a vacuum. It would really help keep that oil at bay.
Do you get plenty of smoke out of that valve breather?
AndyTA is offline  
Old 01-07-2019, 10:18 AM
  #19  
Staging Lane
 
AUS Injection's Avatar
 
Join Date: Aug 2018
Posts: 85
Default

Originally Posted by 98Zheadsncam View Post
I have a set route I use when I take the car out. Some city driving, then I jump on the interstate. It's about 15 miles round trip.
If you drive 15 miles every other week, it should not clog up on you when using E85. Could possibly be an oil issue? Keep us updated, curious for the end results.
AUS Injection is online now  
Old 01-07-2019, 11:53 AM
  #20  
TECH Regular
 
Join Date: Dec 2017
Location: Bossier City, Louisiana
Posts: 408
Default

Alcohol in the E85 does attract water out of the atmosphere and is why many people won't run E10 in their yard toys - mowers, blowers and chain saws, etc. Yea, I understand the advantages to E85 for boost but I think the idea was to burn it faster with more frequent driving to lessen the moisture problems.

I pay 60-70 cents more per gallon around around here for no ethanol pure gas and its worth every penny when I have to restart things in the spring.

Rick
B52bombardier1 is offline  

Thread Tools
Search this Thread

About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: