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glennj3cub · 01-10-2016, 06:16 PM

Well I am again overwhelmed by the input of expertise, it is all so welcome!
So much information I wrote it all down so I don't get wrapped up and forget something.
Actually I thought I fixed it yesterday, found a large vacuum hose from the right valve cover to the air breather was not plugged in. But today I found it was not better.
The tachometer does seem to be involved with the problem, then it may be one or all of the above as it does not take the gas well, skips sputters and even coughs while driving down the interstate, then things smoothed out very well. So it seemed sporadic at times.
I bought plugs this evening, so will just plan on getting wires tomorrow too.
But first off, I am going out tonight and check the wires in the dark and look for any sparks flashing around.
So you say it is electronic ignition. I know I did not see any coil anyplace.
Also I need to find that fuel filter in line. This is a 1987 Holiday Rambler 32 foot. To save my a lot of crawling underneath. About where would I find it? Also, I assume there is a screen filter at the carb itself?
Pertaining to the vacuum. It has a good vacuum with a gauge in dash. Seems it runs about 20 lbs while driving, maybe less I don't remember. But when I slow to idle, the vacuum goes up a lot.

TQ60 · 01-10-2016, 06:37 PM

Vacuum reads in inches mercury and 20 while cruising is great.

If the distributor cap is about 5 or 6 inches in diameter and no wire in the center the coil is in the top of the cap.

Be careful as that unit is capable of 60 to 80 KV so it will reach out and grab you if you are wiggling a plug wire while engine running.

You can get a spray bottle and fill it with water and while engine is idling gently spray water on everything that looks like anything but a bolt.

If a vacuum leak the engine will change.

Same for plug wires and a leaky wire may cause a stumble.

The hose from air cleaner to valve cover is the inlet side of the PCV system.

When it stumbles what does the vacuum gage do?

A lack of spark due to bad wires is great cruise and maybe acceleration but no power.

Power requires more fuel that requires more spark and leaky wires or high resistance wires limit the spark.

In teenage years we had a F100 with the 300 six and it passed smog and ran great but first trip over the grapevine and the big rigs were passing us while camping on their horns!

We were cruising 60 tp 70 MPH just fine with the 55 limit.

In LA we changed the wires and no problem at all...made a believer in me regarding proper tuneup.

glennj3cub · 01-10-2016, 07:09 PM

Great, I have only information now.
First off, no sparks anyplace in the dark with the engine cover off. I did see something unusual regarding a spark. Inside of the carburetor between the 4 barrel leaf, I saw a regular spark arking from the carb to that leaf. After jiggling the breather that stopped, so something was shorting someplace.
Now to describe what I have, the wires are High energy suppression Cables. The distributor says Delco Remy, it has a blue bottom with a black top. It has wires coming from the left top from a Tach Bat, and wires coming from the bottom front going to that Tach bat plug. It certainly did not crank up when I unplugged those wires.
Looks like the top black part holds the wires in place on the distributor and has a snap on top.
Was really running rough tonight, tachometer all over the place.
Vacuum was 15 lowest and around 20 at high idle. Put her in gear, gave a little gas while holding the brake and the vacuum went down below 10, it would not take the gas and wanted to choke down.
I would sure like to pull the distributor and take a look inside of that.
Also want to locate if there is a screen filter at the carb?
I probably need to replace all of those small 5/32 hoses, they are cracking where plugged in and rub off black on my hands.
Looks like a lot to do and takes a lot to remove the entire breather but must be done!

Still trying to figure out why the cruse control don't work while I am in there!

Deano56 · 01-10-2016, 07:34 PM

Quote:

Originally Posted by glennj3cub

Great, I have only information now.
First off, no sparks anyplace in the dark with the engine cover off. I did see something unusual regarding a spark. Inside of the carburetor between the 4 barrel leaf, I saw a regular spark arking from the carb to that leaf. After jiggling the breather that stopped, so something was shorting someplace.
Now to describe what I have, the wires are High energy suppression Cables. The distributor says Delco Remy, it has a blue bottom with a black top. It has wires coming from the left top from a Tach Bat, and wires coming from the bottom front going to that Tach bat plug. It certainly did not crank up when I unplugged those wires.
Looks like the top black part holds the wires in place on the distributor and has a snap on top.
Was really running rough tonight, tachometer all over the place.
Vacuum was 15 lowest and around 20 at high idle. Put her in gear, gave a little gas while holding the brake and the vacuum went down below 10, it would not take the gas and wanted to choke down.
I would sure like to pull the distributor and take a look inside of that.
Also want to locate if there is a screen filter at the carb?
I probably need to replace all of those small 5/32 hoses, they are cracking where plugged in and rub off black on my hands.
Looks like a lot to do and takes a lot to remove the entire breather but must be done!

Still trying to figure out why the cruse control don't work while I am in there!

you really need to start at a general tune up, cap and rotor, plugs and wires, 110 bucks should do it. That sparking at the carb really needs to be solved, maybe first of all. Trace that wire, there has to be a bare wire touching.

TQ60 · 01-10-2016, 09:18 PM

You may have a thermo quad with an insulator under it.

Electric choke may be shorting to carb so unplug it and see if sparking tops.

This is top priority as spark and gas equals boom...

Get a manual tomorrow as you need it badly.

It will explain everything.

Replace hoses and do the tune up but get a manual so you get it done correctly.

twinboat · 01-11-2016, 06:16 AM

Haven't been following this thread, but if you have sparks in the carburator throttle plates, you could be grounding the engine thru the throttle cable.

Take a battery jumper cable and run it from the engine block to the chassis.

Does your negative battery cable have the small wire from it, hooked to a ground point ?

MotorPro · 01-11-2016, 08:05 AM

They don't put thermoquads on Chevrolets.

LETMGROW · 01-11-2016, 08:36 AM

Don't bother looking for an in line fuel filter on the frame. This is only on fuel injected engine models.
Your engine will have a filter in the carburetor. NAPA# 3052. Remove the fuel line then unscrew the filter housing. Be careful not to lose the spring behind the filter. It has to be there for the filter to operate correctly. There is also a clear plastic gasket attached to the filter housing which can get out of place when removing the filter. Be sure this is in place before screwing the filter housing back into the carb. You want to be sure you screw the filter housing straight into the carb. These are easy to cross thread and strip. You should be able to screw the housing in several threads by hand if it is in position properly.
I use a couple wraps of teflon tape on the fuel line threads before screwing the line back into the filter housing.
The filter housing and line should be snug but not overly tight. Again the filter housing is easy to strip the threads on.
Start the engine with the air cleaner off and check carefully for leaks.
I would change the distributor cap and rotor, plugs and plug wires. If you change the cap you will have to remove the coil from inside the cap and install it in the new cap. The two wires from the coil will push out from the bottom of the cap. There is also a wire or strap which goes from under the coil to the center of the opening where the coil wires go in. DO NOT leave this out. The cap will have a button and insulator which must be properly placed in the cap. The new cap will come with these parts. Use them.
Lynn

George Schweikle · 01-11-2016, 08:40 AM

glenn,

As others have said the engine problem is likely electrical, but it would still be good to change the fuel filter. It is approximately half way between the gas tank and engine - on the passenger side at or near the upper part of the frame rail.

When driving our old Winnebago with cruise control engaged, the cruise would add more throttle when climbing a slight hill and the engine would cough or miss. When this happened, I knew it was time to change the filter.

Quote:

Originally Posted by glennj3cub

...Also I need to find that fuel filter in line. This is a 1987 Holiday Rambler 32 foot. To save my a lot of crawling underneath. About where would I find it? Also, I assume there is a screen filter at the carb itself?....

38Chevy454 · 01-11-2016, 08:49 AM

You have what is called the HEI (High Energy Ignition) system. The coil is in center of the cap. There are four screws on the side of the cap that you turn 90 degrees, and then remove the clip for the batt and tach electrical connections, and the cap should come off. Get *good* quality new cap and rotor, ones with brass terminals. This is not an area to cheap out. Remove and replace is simple, the rotor just lifts off after a couple screws are loose, same with the coil in center of the cap. The new parts will help you see. There is probably a hold-down piece for the spark plug wires on the cap, just remove it and save for reinstall later. Once you replace the cap and rotor, then put new again good quality wires on in same order and location as the old cap. Put new spark plugs at the same time, and keeping them in order is a good diea to see if one (or more) cylinder looks different than the rest. Once all back together you have now done the ignition side tune-up.

It is possible the tach could be causing your issues, but my guess is the ignition tune-up will clear up all of your problems.

George Schweikle · 01-11-2016, 09:19 AM

Respectfully not correct. My 1983 Winnebago Chieftain, GM P-30 series chassis, had an in-line fuel filter located on the passenger side frame rail and I'm assuming the original poster has a similar filter on his 1987 P-30 chassis.

Quote:

Originally Posted by LETMGROW

Don't bother looking for an in line fuel filter on the frame. This is only on fuel injected engine models...

LETMGROW · 01-11-2016, 09:43 AM

Quote:

Originally Posted by George Schweikle

Respectfully not correct. My 1983 Winnebago Chieftain, GM P-30 series chassis, had an in-line fuel filter located on the passenger side frame rail and I'm assuming the original poster has a similar filter on his 1987 P-30 chassis.

Could be. The diagram I pulled up didn't show an inline filter but there could be one. Won't hurt to look.
Wouldn't be the first mistake I ever made nor the last I'm sure.
Lynn

tomwalt · 01-11-2016, 09:46 AM

Quote:

Originally Posted by glennj3cub

I probably need to replace all of those small 5/32 hoses, they are cracking where plugged in and rub off black on my hands.
Looks like a lot to do and takes a lot to remove the entire breather but must be done!

Still trying to figure out why the cruse control don't work while I am in there!

Good clue here. Something simple/cheap to try - you can cut 1/2 inch or so of the vacuum lines where they plug in and re-attach. The ends are where they usually crack/leak prior to the entire line failing.
Visually check at cable clamps, rubbing spots, close proximity to exhaust/engine heat as best you can. If the vacuum lines are cracked/disintegrating they should be replaced but by trimming the ends you can usually reduce vacuum leaks to see a difference.

38Chevy454 · 01-11-2016, 09:59 AM

Oh yeah, forgot in my other post, that large diam hose that went from valve cover to air cleaner is part of your crankcase ventilation system. The PCV sucks the vapors from inside the engine, and burns them. The supply air for the crankcase comes from the air cleaner hose, the idea being to provide cleaner filtered air. That would not cause any missing, and since yours is intermittent, that really points to ignition as the source.