1st time buyer. 454 ignition/fuel system info needed.

Started by rcaircraftnut, December 27, 2010, 02:07 AM

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rcaircraftnut

Im looking at buying an 82 RV. The sellers dont know much about it as it belonged to family. So far I know it will cost me $500 to buy it, and its around 30 feet long. From discription I believe it to be a class A. The deal is this, it was driven in and parked, and now wont start. It has had this issue since shortly after being parked, and has been parked now for about 5 months. I am a pretty good mechanic but know almost nothing bout RVs. Besides fuel filters and ground connections what should I look for? Are there any systems that would shut down the engine in the case of a problem? Like fuel or ignition cutoffs. Oil pressure cutoffs ect. I have to drive 2 and a 1/2 hours to go get it, and I want to get it going without spending a week learning new systems the hard way, lol. Thanks in advance as Im sure Ill need lots of help geting the old girl back up and livable. I have to move into it by Feb 1st as thats when I lose the house.

GWINGER

Try to fire it using starting fluid. If it fires check for fuel.
Bad pump, blocked filters ( one in the fuel inlet and one may be on the frame rail), cracked fuel hoses.
If it don't fire check ign. On the early HEI systems the
rotor would go bad and leave you stranded. Check for voltage to the coil and  check the module. The repair manual for 1-ton Chevy trucks will be all that you need to troubleshoot the issue. Good Luck.
J

LJ-TJ

Morning Mate, Ya need two things to get her running. 1) fuel 2) spark. Now most if not all these old girls are built on a 1 ton truck frame so there's nothing special about them they just happen to have house body on them. I think the first thing I'd do is check and make sure I have a strong battery (12 to 14 Volts) . Second thing I would do is pull the coil wire and turn it over to be sure I had spark at the coil. If you don't have spark at the coil chances are you got a bad coil. If I had spark at the coil I would then pull a pug and make sure I had spark at the pug. No spark at the plug probably a bad rotor or points or distributor cap. Got spark at the pug good deal. So we're getting spark.
Now I'd take the air filter off and look down the carb and pump it to see if I was getting fuel to the carb. If it wasn't getting any fuel I'd undo the fuel line at the fuel pump that goes from the fuel tank to the fuel pump to see if I was getting any fuel from the fuel tank to the fuel pump. If not then you may have a plugged fuel line (fuel filter) between the fuel tank and the fuel pump. If your getting fuel from the tank to the pump then the next thing I'd do is re attach the fuel line from the tank to the fuel pump and undo the fuel line from the fuel pump to the carb. I would then turn the engine over to see if the fuel pump was pumping fuel. If not then chances are that the fuel pump is gone and you'll need to replace it. If it's pumping fuel but your not getting any fuel to the carb then you probably have a restriction in the fuel line between the fuel pump and the carb an in-line fuel filter that's plugged or there may be a fuel filter in the carb that needs replacing or cleaning. If you have SPARK and Fuel she should start. If you plan on using a starter fluid(ether) be real careful you can ruin an engine real quick with that stuff.  Hm? Be sure to let us know how you make out.

Oz

So, basically, you need to get a rig running that's been sitting for a long time.

As the old saying goes, "An ounce of prevention saves a pound of repair."  Or, something like that.

There's a lot of things to look at, both to hopefully prevent a breakdown and for the safety of you and others.

Read this Member Article on preparing a Motorhome for use, written by Lefty Rice:
http://www.classicwinnebagos.com/forum/index.php?topic=3976.0
1969 D22, 2 x 1974 D24 Indians, 1977 27' Itasca

RV Mech Tech

In addition to the above posts and the member article by Lefty Rice, there are a few other things you can check for -

A) electrical/ignition - an 82 454 has an HEI electronic ignition and there is info in the member area and resource library for these systems including wiring diagrams for the distributor system - if the problem is no spark at the plugs check for the following -
     1)  make sure you have full voltage at the large red wire gong into the distributor cap/coil assembly - the power for this wire is controlled by the ignition switch and any less than 12 volts will cause problems - the wire has a plastic connector with a fragile tab on it so be carefull when removing it
     2)  G.M. HEI ignition coils sit inside the distributor cap (internal coil) and there is no coil wire from the cap to an externally mounted coil as on some Ford and Mopar engines of those years - you can pull the coil cover off of the cap and remove the coil - it will have two or three short  wires with blade type terminals (one of them is the power feed from that red wire) and check to make sure that they are not broken - the coil transfers its charge into the distributor into the rotor at the bottom of the coil through a small spring and carbon brush piece and that button touches the blade of the rotor underneath - if a lower quality cap or rotor parts are used there may be a "burn through" in the cap (under the coil) or the rotor itself may be burned and shorted out (to the mechanical advance weights under the rotor) so check for this - the higher quality cap and rotors prevented this - this will stop the discharge from the coil from reaching the rotor and will cut off the spark to the plugs 
     3) by 1982, most G.M. vehicles did have an oil pressure cut off switch that prevented the ignition system from working if the oil pressure decreased or shut off altogether - it will be located at the back of the intake manifold (usually in a brass ' T ' fitting and pipe mounted in the engine  block) or above the oil filter mounting pad (usually on a Chevy big block) - check the wire connector to make sure it is not defective or covered in oil from a leaking o.p. switch 

B)  if the problem is fuel related  and you have already done the regular checks then look for the following additional things-
     1) if the RV has an auxiliary gas tank the fuel crossover switch may be defective and preventing the fuel from reaching the engine - if you have fuel injection (1982 trucks usually had throttle body injection) you may have separate electrical fuel pumps mounted inside the fuel tanks ( this was used usually  for duel fuel fleet vehicles )  or an externally mounted electric fuel pump ( or mechanical pump) drawing fuel through the crossover switch and whatever tank was selected (this is most commonly found on RV's) - the GMC motorhomes had a similar setup and considering the age of the RV's these crossover switches can stick between two positions and cut off the fuel - you may also have an additional mechanical pump mounted on the engine - there is info in the resource library for these systems   
     2) keep in mind also that prev owners may have added  additional cutoff switches, fuel filters and who knows what so check for the obvious first -  considering  the situation for this RV I would make sure you have enough tools and some supplies since you have to travel a distance to get to it- extra wire, connectors, a set of spark plugs, some starting fluid ( use as little as possible of this stuff as you can damage the engine internally - two or three short shots is all you need if you are testing for a fuel problem ) , some  1/2" and 3/8"  fuel line and clamps, a fire extinguisher,  a small can to catch fuel in,  a multimeter, a good trouble light, and a good set of  wrenches and sockets are the minimal you will need - if you do have fuel injection you can watch the injectors as you are cranking over the engine - they should spray fuel into the throat of the  TBI body ( in pulses) as you would check if you have a carburetor - and remember always wear safety goggles when checking fuel systems - I have seen more than one mechanic get a fuel bath when doing this

- I hope this gives you additional things to look for - good luck and let us know what you find !   :)ThmbUp

LJ-TJ


GWINGER


DaveVA78Chieftain

Download the Chevy/GM P-30 Service and Maintenace Manual from the Members section.  It lots of useful information especially for the P30 fuel system.
Based on that document:
1. GM did not start installing a fuel cutoff feature on the P30 chassis until 84 or so.  That was in conjunction with a seperate electric fuel pump.  It used the oil pressure switch to control a fuel pump relay circuit.  GM did provide information on how to install that system on a earlier model chassis.
2. They did not start TBI on the 454 based P30 chassis until 90.  The quadrajet carb was used before TBI.

Dave
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HandyDan

In those years it was quite common to have a dual fuel option such as what is on my MH for gasoline and propane.  There is a gasoline fuel shutoff valve right next to the carb that is in the closed position when no electricity is supplied to it.  It does go bad in time or wires get loose, corroded, chewed on, or whatever.  It is a cylindrical stainless steel object about an inch in diameter.  If it isn't getting electricity, you can crank all day long and nothing will happen. 
1984 Holiday Rambler
1997 Newmar Kountry Star

rcaircraftnut

I thank you all for your help. I was not asking what to do to troubleshoot the system, but rather if there were any fuel or ignition cutoff systems I needed to look out for. Thanks HandyDan and the others who respooonded with the answer about the oil pressure cutoff. I am hoping to be getting this RV this week I just sold my 68 Plymouth VIP and now I just need to complete the engine swap in my S10 so I can go get the old girl. Ill let you all know what I find.

rcaircraftnut

Looked at it today. Not in anywhere near as good cond as it was described. Im going to see a 72 Starcraft 24 ft tommorow. $500 asking and it runs.

Oz

Well, I suppose that ends this topic.  I'll mark it solved.
1969 D22, 2 x 1974 D24 Indians, 1977 27' Itasca

GWINGER

Quote from: rcaircraftnut on January 05, 2011, 09:29 PM
Looked at it today. Not in anywhere near as good cond as it was described. Im going to see a 72 Starcraft 24 ft tommorow. $500 asking and it runs.
Let us know how the Starcraft works out.
J