Fuel and Ignition Fuel Pumps and Systems, Ignition and Spark Systems

Dead cylinders after another rebuild

Thread Tools
 
Search this Thread
 
Old Mar 1, 2022 | 07:49 PM
  #1  
Cory Camomile's Avatar
Thread Starter
Registered User
 
Joined: Mar 2019
Posts: 20
From: Salt Lake City Utah
Dead cylinders after another rebuild

More info since signature kept telling me it’s to long
Comp cams valves springs lifters
truck flow 7.20 push rods with trick flow guide plates
fuel pressure 44psi all new NGK 3951 gapped .038
pulled them trying to figure out why we can’t idle and #5 looked as if it has never fired and #2 looks if it’s fired about 20% of the time so been sending Solomon multiple logs trying to track this ghost down but he is at a point of his tune should have me running and I can’t even take it off the jackstands


Recent things I’ve tried are new icm, coil, plug wires msd super conductor checked for resistance 38 ohms to 110 ohms, new plugs again and the exact same #5 and #2 were soaked with fuel but sparkling clean like the car never fired once the two videos are cylinder 5 and 2 old plugs grounded out and me turning motor over with injector fuse pulled and they both spark also I shot some header temps with it gun and I’m 300-550 degrees Fahrenheit on 1,3,5,then 7 was 140 f then #2 4 6 8 are colder than the coolant

please help





Last edited by Cory Camomile; Mar 2, 2022 at 03:20 AM. Reason: adding photos
Old Mar 1, 2022 | 08:07 PM
  #2  
Cory Camomile's Avatar
Thread Starter
Registered User
 
Joined: Mar 2019
Posts: 20
From: Salt Lake City Utah
Re: Dead cylinders after another rebuild

I’ll have to add the attachments when I get home on my laptop
Old Mar 1, 2022 | 10:01 PM
  #3  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,098
From: Hell was full so they sent me to NJ
Re: Dead cylinders after another rebuild

Try swapping #2 (or #5) injector with another cylinder. See if the misfire problem follows the injector.

Additionally, have you checked the fuel pressure to see if an injector or two may be leaking bad enough to flood the cylinders. Attach fuel pressure test gauge, turn key to “run” (not “start”), observe fuel pressure at the instant the pump shuts off (should be at least 40 PSI), watch how fast the pressure drops..

In my PM response I suggested checking for a full 12+ volts, key on, on the pink wire in each injector harness clip. Also check resistance of the injectors (should be 12.5 ohms per AUS).

I'm not familiar with AUS injectors. How did you come to select that brand?

Have you checked the plug wire order at the Opti? Hard to cross 2 and 5, but stranger things have happened.

http://shbox.com/1/opti.jpg
Old Mar 7, 2022 | 09:08 AM
  #4  
Cory Camomile's Avatar
Thread Starter
Registered User
 
Joined: Mar 2019
Posts: 20
From: Salt Lake City Utah
Re: Dead cylinders after another rebuild

well after beating my head against a wall for weeks now i finally think i have it narrowed down to a rookie mistake of valve adjustment sent an inspection camera into the plug holes and had open valves on 2 and 5 all the time. will be adjusting all the valves again and putting everything back together in the next day or two hopefully!!!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
RealDealZ28
LT1 Based Engine Tech
13
May 3, 2021 10:04 AM
95maroboi
Forced Induction
3
Mar 19, 2010 11:23 AM
godspeed1976
LT1 Based Engine Tech
13
Oct 13, 2008 09:27 PM
RedIrocZ-28
3rd Gen / L98 Engine Tech
2
Sep 2, 2004 03:11 PM
97TA-WS6-Con
Pacific
17
Mar 23, 2003 09:59 PM




All times are GMT -5. The time now is 09:49 PM.