Go Back   iRV2 Forums > iRV2.com COMMUNITY FORUMS > Vintage RV's
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-09-2013, 04:12 PM   #43
Senior Member
 
monkey's Avatar
 
Join Date: Sep 2011
Location: Arkansas
Posts: 2,250
Quote:
Originally Posted by Bilito View Post
I know a good test is when all the cylinders are with 10% of each other, but what should a good test show as average?
What year is this 460 ?? I'll look, but I'm sure you can search it as far as PSI. And yes, if they are all within 10%, then look elsewhere for the problem... From what you have explained, sounds like a burnt/leaking valve, but compression test should tell that... As far as valves, when you do the compression test, if you hear air leaking from the intake(carb), then it's an intake valve. Exhaust hissing of course is an exhast valve. (more common) Either way, IF thats it, a totally valve job is coming. I think you have covered all the other problem areas...
__________________

__________________
Monkey, pilot of a Great Dane hauler,
2015 Silverado 2500 Duramax/Alison 4x4 CrewCab 2016 Cougar 28SGS
1ST CAV
monkey 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 06-10-2013, 10:39 AM   #44
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by monkey View Post
What year is this 460 ?? I'll look, but I'm sure you can search it as far as PSI. And yes, if they are all within 10%, then look elsewhere for the problem... From what you have explained, sounds like a burnt/leaking valve, but compression test should tell that... As far as valves, when you do the compression test, if you hear air leaking from the intake(carb), then it's an intake valve. Exhaust hissing of course is an exhast valve. (more common) Either way, IF thats it, a totally valve job is coming. I think you have covered all the other problem areas...
I know how to do all the tests, (ex pilot/mech), just find it difficult to get in there and do them, plus today is the first day without rain,(so far) I hate to have to crawl under there to get at the plugs with the wet ground, and skeeters. I was hoping it would be something easy like a bad wire, vac leak or a cracked cap. Rebuilding the carb will be a bear just to get it out, I have all that emissions crap all over the place and to get at the plugs I have to crawl up in the wheel wells.
This is a big motor, when I turn the front ac on it does not even notice, no drop in rpm or anything it just starts to run, if I put it in gear at idle it moves the RV right along
__________________

__________________
Bilito is offline   Reply With Quote
Old 06-10-2013, 05:00 PM   #45
Senior Member
 
monkey's Avatar
 
Join Date: Sep 2011
Location: Arkansas
Posts: 2,250
Quote:
Originally Posted by Bilito View Post
I know how to do all the tests, (ex pilot/mech), just find it difficult to get in there and do them, plus today is the first day without rain,(so far) I hate to have to crawl under there to get at the plugs with the wet ground, and skeeters. I was hoping it would be something easy like a bad wire, vac leak or a cracked cap. Rebuilding the carb will be a bear just to get it out, I have all that emissions crap all over the place and to get at the plugs I have to crawl up in the wheel wells.
This is a big motor, when I turn the front ac on it does not even notice, no drop in rpm or anything it just starts to run, if I put it in gear at idle it moves the RV right along
I totally understand ... I was an A&P mech,, twin engine turbo props, built many a Mopar hotrod , but it took me a week to change plugs on our 350 chevy... Geez, what a PAIN to get to everything, then they had been in there so long, the threads were carboned up where they wouldn't come out. Most you couldn't even see,,,, just feel.. It would be nice to have a big block, so we could tow her little car, but you can't beat 12-13 mpg... Guess it's a trade off, till we upgrade... Keep us informed... Monkey
__________________
Monkey, pilot of a Great Dane hauler,
2015 Silverado 2500 Duramax/Alison 4x4 CrewCab 2016 Cougar 28SGS
1ST CAV
monkey is offline   Reply With Quote
Old 06-11-2013, 11:10 AM   #46
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by monkey View Post
I totally understand ... I was an A&P mech,, twin engine turbo props, built many a Mopar hotrod , but it took me a week to change plugs on our 350 chevy... Geez, what a PAIN to get to everything, then they had been in there so long, the threads were carboned up where they wouldn't come out. Most you couldn't even see,,,, just feel.. It would be nice to have a big block, so we could tow her little car, but you can't beat 12-13 mpg... Guess it's a trade off, till we upgrade... Keep us informed... Monkey
Flew the early Bandits, Casa 212, C-441 My fav were the C402C and the DC -3, changed many a jug on both, at least we could get at and see what we were working on
__________________
Bilito is offline   Reply With Quote
Old 06-12-2013, 12:12 PM   #47
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Bilito View Post
No I have not done a compression test, guess when the ground dries out and we can get under there I can pull the plugs one at a time and screw in the compression tester at that time.
Wow what an experience, took about two hours to pull plugs 6 7 and 8 and test the compression, on the left side of the motor they are all but impossible to get at

We started with number 8, it had 95 PSI the next two had 120 each, the last one we did was number 6 and the plug was all fouled and covered in black soot, I believe the plug is bad, gotta retest number 8 for compression we might not have had the tester in there good and tight

It is now pouring down rain again, went to the store and bought another plug, I m hoping that was the problem, we still want to test the compression on all the rest of the cylinders,
During the test of plug 7 the starter solenoid stuck and kept cranking the motor, had to run fast to find something to smack it with, hope we did not screw anything up.

Cannot do anything now until it stops raining
__________________
Bilito is offline   Reply With Quote
Old 06-12-2013, 12:36 PM   #48
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Bilito View Post
Wow what an experience, took about two hours to pull plugs 6 7 and 8 and test the compression, on the left side of the motor they are all but impossible to get at

We started with number 8, it had 95 PSI the next two had 120 each, the last one we did was number 6 and the plug was all fouled and covered in black soot, I believe the plug is bad, gotta retest number 8 for compression we might not have had the tester in there good and tight

It is now pouring down rain again, went to the store and bought another plug, I m hoping that was the problem, we still want to test the compression on all the rest of the cylinders,
During the test of plug 7 the starter solenoid stuck and kept cranking the motor, had to run fast to find something to smack it with, hope we did not screw anything up.

Cannot do anything now until it stops raining
here is a plug comparison
Attached Thumbnails
Click image for larger version

Name:	IMG_0467.jpg
Views:	61
Size:	160.4 KB
ID:	40598  
__________________
Bilito is offline   Reply With Quote
Old 06-12-2013, 01:20 PM   #49
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Bilito View Post
here is a plug comparison
Question,
I connected the old and the new plug to my lawnmower and they both sparked about the same. Is it possible a plug can fire out of the motor and not fire under compression??
__________________
Bilito is offline   Reply With Quote
Old 06-12-2013, 05:53 PM   #50
Senior Member
 
monkey's Avatar
 
Join Date: Sep 2011
Location: Arkansas
Posts: 2,250
Quote:
Originally Posted by Bilito View Post
Question,
I connected the old and the new plug to my lawnmower and they both sparked about the same. Is it possible a plug can fire out of the motor and not fire under compression??
Yes it is 'possible' . The higher the compression, the more electrical power it takes to fire the plug. That's one reason high compression engines use high performance ignitions. For sure (as you know) that cylinder/plug is a problem. With new cap/rotor , wires, and compression, then the new plug is about it as far as I can think of.
__________________
Monkey, pilot of a Great Dane hauler,
2015 Silverado 2500 Duramax/Alison 4x4 CrewCab 2016 Cougar 28SGS
1ST CAV
monkey is offline   Reply With Quote
Old 06-12-2013, 07:01 PM   #51
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by monkey View Post
Yes it is 'possible' . The higher the compression, the more electrical power it takes to fire the plug. That's one reason high compression engines use high performance ignitions. For sure (as you know) that cylinder/plug is a problem. With new cap/rotor , wires, and compression, then the new plug is about it as far as I can think of.
between raindrops I installed the new plug in number 6 cyl, made no diff whatsoever, will try to do the rest of the cylinders tomorrow.
I am hoping that low press in number 8 cyl is just lack of use or not screwing the comp tester in tight
__________________
Bilito is offline   Reply With Quote
Old 06-13-2013, 10:56 AM   #52
Senior Member
 
monkey's Avatar
 
Join Date: Sep 2011
Location: Arkansas
Posts: 2,250
Bilito, I fowarded your story along with the plug picture to a good freind who builds race engines and owns a shop,,, for what little info he has on your problem here is his reply....

Black coloring can be caused by either a miss fire (Could have a bad wire even new. I would trade the plug wire in question with a different cyld and check it again in a few hundred miles.. OR flooding, but not likely since the other cylds at said to be okay..so needs to find his misfire.. could be sparking to ground AFTER motor gets hot under the hood.. I assume it is a carbrutor motor... hope this helps...
__________________
Monkey, pilot of a Great Dane hauler,
2015 Silverado 2500 Duramax/Alison 4x4 CrewCab 2016 Cougar 28SGS
1ST CAV
monkey is offline   Reply With Quote
Old 06-13-2013, 01:26 PM   #53
Senior Member
 
Dave78Chief's Avatar
 
Join Date: Jun 2009
Posts: 1,513
Bilito - Sorry I have not been around much. You guys look to be on the right track though. Good luck - Dave
__________________
Dave in Virginia
1978 Winnebago Chieftain
Dodge M400 - 440-3
Classic Winnebago Site: http://www.classicwinnebagos.com/forum/index.php
Dave78Chief is offline   Reply With Quote
Old 06-14-2013, 12:17 AM   #54
Senior Member
 
Join Date: Feb 2010
Posts: 4,493
Talking

somewhere it was stated that when the wire was remove the expected "snap" was NOT there while also not being knocked on one's tail.

Proper working late model ign system can generate about 70 to 80 thousand volts, it can climb right up a damp wire and nail you to the hood.

The plug keeps the voltage down to the amount restricted by the spark.

If no pop then the spark is shorting to ground somewhere, the wire could be pinched somewhere or just bad.

Best to remove wire with engine off, place it on an old plug and rest it on the engine someplace, hold the wire and you will discover how well the system really works!
__________________
Tony & Lori
1989 Country Coach Savannah SE
TQ60 is offline   Reply With Quote
Old 06-14-2013, 12:46 AM   #55
Senior Member
 
stink's Avatar
 
Join Date: Apr 2012
Posts: 1,414
I found on the older 460s number 7 and 8 are next to each other in firing order. Suggest separating the plug wires. If the wires run together, they will crossfire. Number 8 compression may be low because of this misfire. Ford big blocks also had an intake manifold leak issue that you can check by spraying the joining surfaces with carb cleaner while the engine idles. When you find the vacuum leak the engine will smooth out. The egr plate under the carb had a habit of burning thru or warping causing vacuum leak there. You may need to remove carb to remove egr plate and inspect.
Disconnecting the thermactor system will do nothing but increase emissions. No hp gains, no mileage gains. If you decide to disconnect the egr you will get severe pinging under load. Hope this helps.
__________________
Dave and Laura & two cats
02 Discovery with Accord toad
retired auto rv tech and teacher, wife rt nurse
stink is offline   Reply With Quote
Old 06-14-2013, 06:58 AM   #56
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Bilito View Post
Got the final three wires and installed them, still seems to have a misfire, If I put my near ther exhaust pipe I can feel the popping, snorting, puffing or what ever you want to call it, it is running real good except for that slike shaking at idle and that popping of the exhaust. Is it possible that a new plug can be bad and not spark?
Note about NAPA service
When I went in, 3rd trip about the 3 wires too short, I was told to return the next day as they would have another set of my wires then. I went back, they had the wires but were reluctant to give me three longer wires saying they would end up with a bad set also the coil wire was wrong with the coil end having the wrong fitting, salesman showed me what he called a hi dollar set and it had the correct coil wire but he refused to give it to me saying if he did he would then have two bad wire sets, he told me to come back tomorrow for the correct wire, I go back the next day he handed me a wire clip and a plug boot and said they would fit if I cut the wires and repaired it myself and then charged me 1.26 for the parts, I was shocked and went home, (6 days back and forth for a set of plug wires was wrong). I was so pissed I got online and wrote to NAPA cust service and told them my story, got a return email saying they would look into it. Yesterday I get a call from the mgr at the napa store apologizing and asking me to come to his store so they can make it all right. Go to the store, meet the manager he apologized and handed me a gift certificate for 50 for my gas, a new complete set of the hi dollar plug wires and the correct coil wire and said this never should have happened and he hoped I would still come to his store, he promised to make all his employees understand that it is the customers that pay the salary and to not let one ever leave dissatisfied.
Now I have to change all the wires again, these new wires are actually much nicer looking wires
__________________

__________________
Bilito is offline   Reply With Quote
Reply

Tags
ford



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


» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 12:45 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.