Go Back   iRV2 Forums > THE CHASSIS CLUB FORUMS > Workhorse and Chevrolet Chassis Motorhome Forum
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 01-12-2014, 11:49 AM   #1
Senior Member
 
deputydog's Avatar
 
Workhorse Chassis Owner
Join Date: Mar 2008
Location: Gainesville FL
Posts: 210
Anybody pulled the fuel rail and injectors on 8.1L?

Has anybody out there pulled their fuel rail and injectors on the 8.1L vortec?

I'm about to that point but can't decide to do it or take it to a GM dealer and let them do it. It's pretty accessible through the dog house and it's only 4 bolts I think but there are some wires that I can't tell for sure if the rail can be raised high enough to get the injectors out without messing with a bunch of wiring.

I've got a under-load miss and so far have: cleaned the MAF and replace the air filter, cleaned the throttle body, replaced the fuel filter, tested all the plug wires (Taylor 409's) with ohm meter - all about 360 ohms, replaced plugs (AC Delco gapped at .060) and checked fuel rail pressure (steady at 64 psi at idle up to 2000 rpm) and cleaned the fuel rail at 55 psi with 50% sea foam/50% 90 octane non-ethanol fuel) - 16 oz. total mixture (did this twice) and then once with 25% Techron and 75% fuel and cleaned intake with 1/2 can of Seafoam through the throttle body.

I guess my intake was relatively clean because there was little to no smoke while injecting the spray Seafoam and immediately after when I test drove it aggressively to blow out any carbon.

It ran and idled fine for the first 5 minutes or so after I did the fuel rail and intake cleaning but then started missing at idle. I kept on driving to see if maybe a plug was fouled and it might burn off but it got progressively worse as the drive went on and was skipping pretty badly under load and acceleration was poor with the miss toward the end of about a 30 mile drive.

I can't decide if it might be a coil breaking down under heat and or moisture (originally started as a skip early in AM when there was a lot of moisture on the motor from cool temps and high humidity) or an injector that might have a clogged filter and possibly the rail cleaning moved the particles around in the injector and made it worse.

My scanner does show any miss-fire codes and the MIL light does not come on and there are no saved codes.

I think the dealers have a lot better scanners that can show pending codes and miss-fires that mine does not which is why I am thinking about going to them.

For the 8.1 to supposedly be a bullet-proof motor that passed the marine tests, mine has had more than it's share of issues in the 13,000 miles that I have put on it. When it runs right it is great, but I'm loosing confidence in it and that's no good if you want to take a trip and relax and instead you are worrying about what will crap out next.

Thoughts and comments are appreciated and if you know of a good dealer in Gainesville Florida let me know.
__________________

__________________
Deputydog
2005 34' Allegro Bay W22/8.1L
Tiffin Coach Owner's Forum Member
deputydog is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 01-12-2014, 12:01 PM   #2
Registered User
 
Join Date: Mar 2013
Posts: 1,919
Before anything I would replace the wires with a good set of AC Delco ones. Checking plug wire resistance can detect a problem but in most cases the wire insulation breaks down and you will get coil voltage arcing to ground. A coil would also be suspect as it may not be able to handle the higher resistance incurred from high cylinder pressures while driving under a load.
__________________

jamesrxx951 is offline   Reply With Quote
Old 01-12-2014, 12:08 PM   #3
Senior Member
 
Join Date: May 2005
Posts: 443
I like your coil breakdown thought, as that will often show up as a heavy load miss that degrades to a miss at low or no load. I would spray a liberal amount of WD 40 on the coils, let it sit 30 minutes and then road test. If the coil break-down is external the WD40 will temporarily help it to run much better.Keep us posted.
__________________
04 Southwind 37C W22

DIY Rear Panhard Rod
exrench is offline   Reply With Quote
Old 01-12-2014, 12:12 PM   #4
Registered User
 
Join Date: Mar 2013
Posts: 1,919
In the past I have sprayed a light mist of water on coils and plug wires. This can help with finding an arcing coil or wire. It would be nice if the OP had access to a misfire monitor program like the Ford diagnostic tools have. You can swap a wire or coil to see if the misfire changes cylinders. This helps a lot to find an ignition fault or in very rare cases an injector issue.
jamesrxx951 is offline   Reply With Quote
Old 01-12-2014, 12:19 PM   #5
Senior Member
 
Ford Super Duty Owner
Join Date: Jan 2011
Location: Lowell, Arkansas
Posts: 5,281
As I was reading your post I thought and wondered if James was checking the treads. Yep he was and is answer is about as I thought. When you check resistance that's OK but the wires are not under load. Your ignition system is capable of producing a lot more voltage than it needs to get the spark to jump at the gap. Under operation the conditions change inside the combustion chamber and there are times when more voltage is needed to overcome all the resistance so the coil will put out as needed to get the job done. When the insulation is compromised by age and moisture the resistance becomes lower. The voltage that did get to a plug under easier conditions now goes to ground down an easier path and you have a stumble/miss.

There may be some other issues but first change those wires to eliminate them as a possible source. Yes the engine miss-fire should be caught by the computer.

It seems that you've taken care of a lot of the possible issues. Good job!!!

I've done the same thing with a spray bottle of water. Did it once at night and the engine ignition system looked like a Christmas tree on steroids. By the way that's part of the reason why the industry did away with the spark plug wires and went to the COP system. Secondary insulation breakdown is almost eliminated with no plug wires.

TeJay
__________________
TeJay Auto Instructor/4-yrs USAF/ Liz: RN/ WBGO 2014 Vista 30T/ F-53/CHF/5-Star/Koni * Bella & Izzy * Golden /Cocker mix/ Louie The Cat* All Retired
TeJay is online now   Reply With Quote
Old 01-12-2014, 02:03 PM   #6
Senior Member
 
Arch Hoagland's Avatar
 
Monaco Owners Club
Workhorse Chassis Owner
Join Date: Aug 2002
Location: Clovis, CA, USA
Posts: 6,811
Missing at idle is a bit different...is there any problem under heavy load..accelerating or climbing mountains?

I think I'd take a look at night time and see if there is any arcing.

My limited knowledge of spark plug wires has proved to me to use ONLY wires, and plugs, from the OEM.

I've had problems with after market wires and plugs on a couple different cars.
__________________
2004 Monaco La Palma 36DBD, W22, 8.1, 7.1 MPG
2000 LEXUS RX300 FWD 22MPG 4020 LBS

Don't know where I'm going, spose I'll get there anyway.
Arch Hoagland is offline   Reply With Quote
Old 01-12-2014, 05:14 PM   #7
Senior Member
 
deputydog's Avatar
 
Workhorse Chassis Owner
Join Date: Mar 2008
Location: Gainesville FL
Posts: 210
Issue resolved - I should have known!

Well I finally figured it out. I had done as some of you suggested and looked in the dark for sparking and also listened for that "tick-tick-tick" of a spark to ground but did not have any. Also checked for any vacuum leaks.

I decided as a last ditch effort today to replace all the spark plugs even though the ones in it only have probably 3,000 miles or so. When I got under there to make the change I had difficulty removing two of the plug wires. It took a real effort to get them off the plug. Once they were off both had humps on the plug end (see photos) unlike any of the others so I decided to replace them with a couple of the old OEM wires I took off when I put these super-duper Taylor 409's. Problem solved and it runs like a top now. Just took a 50 mile trip and runs like new.

I had one OEM wire breakdown and spark to ground so I ordered the Taylor 409's because everybody said they were great. From my experience they aren't worth a flip.

I have had two of the Taylors split the plug boot (see photo) and now two more swell up at the plug boot. I cut one open so see what the deal was and as best I can tell there must be arcing where the wire is connected to the plug clip and that melted and swelled up the red part which caused the hump in the plug boot. (see photos).

I'm going to go back to OEM wires and keep these as spares. I sent Taylor a photo of the two split boots and they said they were out of warranty and I would have to buy new ones which I did. Don't think I'll bother calling them this time. Learned my lesson.

I think next time the toilet doesn't work right in my coach I'll just replace all the plug wires and that should fix the problem

Thanks for all the comments - maybe this will help somebody else.
Attached Thumbnails
Click image for larger version

Name:	IMG_3576.JPG
Views:	214
Size:	73.7 KB
ID:	53728   Click image for larger version

Name:	IMG_3578.JPG
Views:	144
Size:	60.0 KB
ID:	53729  

Click image for larger version

Name:	IMG_3579.JPG
Views:	205
Size:	70.9 KB
ID:	53730   Click image for larger version

Name:	IMG_3580.JPG
Views:	151
Size:	59.6 KB
ID:	53731  

__________________
Deputydog
2005 34' Allegro Bay W22/8.1L
Tiffin Coach Owner's Forum Member
deputydog is offline   Reply With Quote
Old 01-12-2014, 05:22 PM   #8
Senior Member
 
Arch Hoagland's Avatar
 
Monaco Owners Club
Workhorse Chassis Owner
Join Date: Aug 2002
Location: Clovis, CA, USA
Posts: 6,811
Thanks for the update...as for the toilet, you'll need to get OEM water.........
__________________
2004 Monaco La Palma 36DBD, W22, 8.1, 7.1 MPG
2000 LEXUS RX300 FWD 22MPG 4020 LBS

Don't know where I'm going, spose I'll get there anyway.
Arch Hoagland is offline   Reply With Quote
Old 01-13-2014, 06:37 AM   #9
Senior Member
 
mgscott4's Avatar
 
Workhorse Chassis Owner
Join Date: May 2009
Location: Kansas City, MO./Pollock, LA.
Posts: 1,555
Is anybody keeping track? It seems it is either a dirty MAF or bad wires that cause the 8.1 to miss.
__________________
06 Hurricane 34FT WH W20 Chassis 8.1L 132K, Steersafe, Koni Shocks, DIY Trac Bar, Tri-Metric 2025RV Battery Monitor, 4-6V Batteries, Scan Gauge 2, Crossfires, 735W Solar Morningstar MPPT-60, WG T4 In-Motion Sat, XM Radio, 07 Chevy Malibu Maxx Toad, Falcon 2, Brake Buddy, Escapee
mgscott4 is offline   Reply With Quote
Old 01-13-2014, 11:30 AM   #10
Senior Member
 
Arch Hoagland's Avatar
 
Monaco Owners Club
Workhorse Chassis Owner
Join Date: Aug 2002
Location: Clovis, CA, USA
Posts: 6,811
Quote:
Originally Posted by mgscott4 View Post
Is anybody keeping track? It seems it is either a dirty MAF or bad wires that cause the 8.1 to miss.
Yes....see his post #7. Includes some good pictures of the bad after market wires.
__________________
2004 Monaco La Palma 36DBD, W22, 8.1, 7.1 MPG
2000 LEXUS RX300 FWD 22MPG 4020 LBS

Don't know where I'm going, spose I'll get there anyway.
Arch Hoagland is offline   Reply With Quote
Old 01-13-2014, 03:21 PM   #11
Senior Member
 
mgscott4's Avatar
 
Workhorse Chassis Owner
Join Date: May 2009
Location: Kansas City, MO./Pollock, LA.
Posts: 1,555
Arch- what I meant was, I been reading these forums for a couple of years now, and it seems every thread in this Workhorse forum were there is an engine miss it seems that it is either a dirty MAF or bad spark plug wire.
__________________
06 Hurricane 34FT WH W20 Chassis 8.1L 132K, Steersafe, Koni Shocks, DIY Trac Bar, Tri-Metric 2025RV Battery Monitor, 4-6V Batteries, Scan Gauge 2, Crossfires, 735W Solar Morningstar MPPT-60, WG T4 In-Motion Sat, XM Radio, 07 Chevy Malibu Maxx Toad, Falcon 2, Brake Buddy, Escapee
mgscott4 is offline   Reply With Quote
Old 01-13-2014, 04:39 PM   #12
Senior Member
 
Max Hubrich's Avatar


 
Workhorse Chassis Owner
Join Date: Mar 2007
Location: Pikeville, NC
Posts: 1,727
Whew--

Sure beats pulling the fuel rails and injectors and then still having the miss-

An air circulation problem, or lack of cooling air? cooling kit install time ?
__________________
Max H,
2002 Newmar Mountain Aire, 37', 3778, W-22, 8.1 Vortac, Ultra Power upgrade, CAI (cold air intake), Taylor wires, colder plugs, Koni shocks.
Max Hubrich is offline   Reply With Quote
Old 01-13-2014, 07:46 PM   #13
Senior Member
 
Arch Hoagland's Avatar
 
Monaco Owners Club
Workhorse Chassis Owner
Join Date: Aug 2002
Location: Clovis, CA, USA
Posts: 6,811
Quote:
Originally Posted by mgscott4 View Post
Arch- what I meant was, I been reading these forums for a couple of years now, and it seems every thread in this Workhorse forum were there is an engine miss it seems that it is either a dirty MAF or bad spark plug wire.
Got it....you are right...Plugs and Wires.
__________________
2004 Monaco La Palma 36DBD, W22, 8.1, 7.1 MPG
2000 LEXUS RX300 FWD 22MPG 4020 LBS

Don't know where I'm going, spose I'll get there anyway.
Arch Hoagland is offline   Reply With Quote
Old 01-15-2014, 05:53 PM   #14
Senior Member
 
deputydog's Avatar
 
Workhorse Chassis Owner
Join Date: Mar 2008
Location: Gainesville FL
Posts: 210
I have a cooling kit installed - maybe I need to redirect the air - I have it dumping onto the front two cylinders and aimed toward the back ones so it blows on all of them - maybe I need to just aim at the middle or next to back or a bunch of individual nozzles to each - seems like an overkill but I'm sick of wondering when the next miss will take place
__________________

__________________
Deputydog
2005 34' Allegro Bay W22/8.1L
Tiffin Coach Owner's Forum Member
deputydog is offline   Reply With Quote
Reply

Tags
fuel



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Adding ATO or 2cycle to diesel rrray Duramax Engine Forum 24 03-22-2014 11:01 AM
1990 Bounder Diagnostic Port Dilemma thunder47for Ford Motorhome Chassis Forum 51 09-10-2013 12:28 PM

» Featured Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:10 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.