Hello everyone!
So we recently purchased a killer 1985 Monitor RV, based on the E350 Cutaway, Carbureted 460, 38,000 miles on the clock.
It occurs to me that, although I own a shop and built my first car from scratch ('76 Vega, 400sb, "Pre internet", haha), I have become quite dependant on OBD and FI tuning methods, as my main specialty has been later model BMW for many years now.
Of course my first steps have been to go through and replace all the most common elements, plugs, wires, cap, rotor, filters, fluids, etc.
We are about to take a 7k mile road trip, in this RV, in about 10 days.

Upon driving the rig, it starts up and feels pretty smooth, but I am questioning my own perception of how much power this thing should have.
I've noticed the kick down doesn't operate but I'm not particularly concerned about that feature until I can address everything else.

I plan on pulling the plugs and seeing if there is any indication of strange firing conditions, as well as checking conductivity on all the the lead wires.
It was a "kit" type set of wires and I considered the fact that one or more could possibly be not operating at full capacity, causing me to notice/hear/feel what seems like power lacking.

I've also noticed that there appears to be no inline fuel filter on this setup...is that typical?

So ultimately what I am asking is if anyone has any particular tips/suggestions for me and this particular power plant.
It occurs to me that I am so out of touch with Carbureted engines that although my theoretical engine comprehension is great, I'm crossing the logic when diagnosing things by "feel", right now.

Thanks in advance for tolerating what I am sure sounds like the most pedestrian requests.

I'm certainly not asking anyone to hold my hand, lol, just possibly some confirmation!

 

One thing to keep in mind is that 1985 was very near the end of the carbureted era. That poor calibrated leak box atop the intake manifold? It was severely taxed to meet emissions standards, typically at the expense of power output.

Kit plug wires? Never been much of a fan of them. They just don’t seem to last. I much prefer a factory-made set. You can check continuity of the conductors, but that isn’t what usually fails. The more common failure is a breakdown in the insulation’s capability. You need a megohmeter ($$$) to properly check the insulation strength. I’ve never bothered, and just replace them if there’s any doubt.

Fuel filter? Not positive about the 460, but think there’s a filter that screws into the carb inlet. That’s how my 351W is configured.

 

I absolutely agree with the kit plug wires.
It was apparently all my supplier had on hand from a "good" manufacturer.
Far more trouble than it was worth, very time consuming, and the potential problems far outweigh any possible advantages.
I think you are very correct in suggesting using something factory, I am going to go ahead and do that.

I also considered just replacing the carb instead of messing with it. That may be an option before we leave.

Also, I will get rid of all the EGR stuff, although I don't know if that will be before or after this trip.

Thanks for the input.

 

With any type of plug wires, you have to handle them very carefully. It's very easy to break the center conductor, it is nothing but a nylon rope with some sort of graphite in it. If you have to pull the wires off the plugs later on to do some work, I have found that grabbing the boot and pulling on it and twisting at the same time is the best solution to get them off.

You should have a filter screwed directly into the carb fuel inlet. Follow the line from that and you might run across a funny looking can with 3 line connections to it. That is the orifice for the fuel return, you most likely have electric fuel pumps in the tanks with a return line that sends a portion of the fuel back to the tank. This fights vapor lock problems, especially when you are fully loaded and crawling up a mountain somewhere. This is the system (if you have it) that is going to give the most trouble. Dirty rotten ethanol fuel fouls the pumps in the tanks. And then you have a relay and a oil pressure switch that runs the pumps that can fail after so many years.

If it runs good, I would not touch any of the emissions on top of the engine.

 

Poor performance can be caused by a vacuum leak or clogged carburetor/failed power valve--How bout a carburetor rebuild ? The rubber and cardboard components decay in as little as a few years. Gas turns to varnish and dingleberries clog orifices. Gaskets dry out and leak vacuum into engine, leaning it out.

Takes a few hours to disassemble, clean, and screw back together with new parts.

Try bumping the timing up as far as it will go without pinging. You can do this by hooking a vacuum gauge to manifold vacuum and turning distributor until you reach maximum vac reading and then lowering it back by a couple Hg. Also, overall manifold vacuum will tell you if you're engine is in tune. You should see above 17 Hg. Hopefully in 20's.

Also, new plugs with a good sized gap can help.( .040)

You might want to reconnect the kick-down lever to the throttle bracket on carburetor, maybe that will show you some more "power". Should take 5 minutes and an e-clip.
Of all engines, I'd say by '85 the 460 on a motorhome was probably the least R***d by emissions standards. I'd bet all you have is EGR and ported distributor advanced controlled by coolant temp switch. Carb might be calibrated lean. Nothing you can do about camshaft profile or compression.

Finally... should I buy an 09 e90 328i with 94k or am I asking for punishment?

 

How many miles have you driven since the purchase? I'm wondering if you've had any heat-related fuel issues, i.e. the ubiquitous "vapor lock". It would seem the E-series engine compartment could get pretty toasty due to the tight confines, combined with the engine working hard pulling all that weight.

For fuel issues, you may find this thread of interest. I did some research about a year ago, looking into how octane rating affects the fuel's ability to tolerate high underhood temperatures:

https://www.ford-trucks.com/forums/1...g-and-you.html

To summarize Proust (bonus points if you get the reference), years ago higher octane fuel was more resistant to heat problems. Way back when, if you were experiencing vapor lock symptoms, switching to a higher octane fuel was often enough to mitigate the problem. But with modern fuel chemistry, it's just the opposite. Higher octane fuel today is actually more susceptible to heat-related issues. I was following the old advice, and running a mid-grade octane during the summer months, when my truck is working the hardest hauling a slide-in camper. The old advice is no longer current. More long-winded details in the thread linked above. Basically, run a quality brand of fuel in the lowest octane your engine will tolerate without pinging.

 

I took my 83 F-250 out of mothballs after a 30 year rest with 57k on the clock. Really LACKING POWER for a 460, after doing all the usual things to get the cob webs out and running - I took the SMOG crap off since antique plates don't need it. Made a HUGE difference... Don't forget the RUBBER - hoses and belts...

 

Wow that's a lot of info, thank you.
I was really expecting to find fuel filter in line on the frame rail and didn't find one but I'm sure that I did see the three orphus unit you were talking about.
The plug wires I put on where the type you put together yourself and I was pretty sure that somewhere in that system there was something that wasn't working properly.
I got a new set of plug wires today that were pre-made and, although they were some more basic lead wires, I feel it really remedied some of the issue.
I pulled all of the plugs and I noticed the one four cylinder for may have been pinched in the doghouse a bit and that plug was definitely wet.
Although that seemed to make a huge difference I don't know for sure yet.
this was the first measured tank of fuel that I had gone through and although only a portion of that was highway miles oh, my estimated mileage of 5.8 miles per gallon was far less than the advertised average of around 10 miles per gallon.
We've got a little less than a week before we leave now and, I feel that an engine that only has 38,000 miles on it, should only have something fuel-related causing it to have such low mileage.
honestly I check the tire pressure for the first time today and even though they're rated at 80 psi Max, none of them were over 55 and one of them was as low as 40 so, that will make some difference in itself.
Given that it doesn't seem like it's running as perfectly as I feel it should, I think I might still delve into taking off the EGR aspects just to simplify everything.

Oh man, I'm trying to multi quote everything right now on my phone because I left my laptop at the shop but, I can certainly give you expanded knowledge on the E90 purchase, but I think I need to be able to look back and reference better at what I'm saying to be accurate. Long story short, they're fantastic.
In my opinion the worst thing to work on are 90s domestics.
with BMW, everything seems so intuitive and, any issue that can arise can typically be addressed before there's a problem.
I replaced all the spark plug with in gk's, I don't remember exactly which one offhand, but I did check the gap on all of them.
The new, off-the-shelf, plug wires seemed to so far, make a world of difference.
I considered rebuilding the carburetor but, considering we're going to do seven thousand miles, I've also consider the fact that I can get a new carburetor off the shelf, wholesale, and that will offset the cost in fuel savings and time spent messing with it.
I love to tinker and I love to learn new things but at this point we're less than a week away from leaving on this huge trip and I'm a bit concerned that everything isn't as perfect as I would like it to be.
I will make a note to specifically revisit this about the E90 though.
Thank you very much for your input.

I know Proust but, how is octane related to cholera ?? Lol.
This is particularly interesting because, I am a huge proponent of high-octane in pretty much any vehicle because in my experience it's been that this is also a higher grade / purity of fuel so that even if the engine doesn't necessarily benefit from the octane it will benefit from the purity in long-term maintenance aspects.
This kind of turns that mode of thinking on its ear, and demands looking at quality from A supplier as supposed to just defaulting to the fact that typically, in theory, the most expensive one is the best one.

actually, feeling this vehicle up is the first time I've used anything other than premium in more years than I know.
I'm really interested in the logic behind that but just from what you've said it does make sense and I feel better about putting mid-grade in, going only by thinking that the lower octane in itself would be fine in that the higher levels of purity are going to be less of an issue with the more fundamentally simple power plant.

I look forward to reading more into the link tomorrow.



That sounds like exactly what I'm dealing with. I know it's a heavy chassis, I'm not sure what it weighs of hand but I just feel like this giant motor should feel more responsive.
when I first decided to buy it one of the biggest things was the fact that it only had 38 k.
my thoughts were, with such low mileage, mechanically it should be sound no matter what.
I didn't initially take into consideration the fact that it has been run with ethanol gas, stored with ethanol gas, and the fact that a carburetor sitting and not running, is going to pose issues of its own.
last week I was thinking I wasn't necessarily going to pull all that off because, if it were running properly, I was going to let a sleeping dog lie.
At this point, I've got about six days, and I think eliminating the EGR / admissions materials will be time well spent.





Thank you all so much, I did not expect this broad spectrum of replies in such a short perios of time.

I think I'm leaning heavily towards just replacing the carburetor in probably eliminating EGR / admissions, for simplification, at this point.
it would be hard to not justify the carburetor purchase since, the difference between 5.8 and 7 MPG is about 200 gallons, more than enough to pay for a brand new Edelbrock.

I'm a little more comfortable with it now, I was just kind of worried because here I am buying this 34 year old RV and about to drive my family 7000 miles, I had visions of something catastrophic happening on the side of the road, and having to abandon our new house on wheels in order to get back to work!

.

I apologize for any typos or weird sentence structure in advance, I forgot to bring my laptop home tonight and I'm trying to reply to everything on my phone with mostly voice to text because, I'm getting old in my contacts don't work as well on this small screen.

I'll keep you all posted, thanks again, I genuinely appreciate the insight

 

to see the last post as it is not coming up from LB
Dave ----

did not work?

 

Yep, one of the things I had to do was rebuild the carb, and clean out the gas tanks... The Fuel filter on my 460 was about 8 inches in front of the carb, right before it starts to drop down and attach to the fuel line coming up from the tanks.

 

Long time cut away RV owner here. I wouldn’t touch the EGR. At least not 6 days before a big trip.

Biggest gains for me have been in ignition timing.

- I’m running about 10* base advance.
- Check your vacuum advance. Remove the cap, put a vacuum hose on the advance and suck on it to see if the advance mechanism is working properly. You may need to lube the advance to is works freely. If the diaphragm is shot you won’t get any vacuum, you’ll just draw air.
- Give the rotor a little twist to make sure the mechanical advance is free and it return back to zero when you let go if it. You can remove the little felt puck from the top center of the distributor shaft and put a few drops of oil down the center of the shaft to lube the mechanical advance.
- Run straight manifold vacuum to the distributor. Yeah, that’s gonna put you at about 25* total advance at idle but it should be fine. I’ve got a little blue vacuum restrictor in the vac line to the dizzy which just buffers how quickly the vacuum to the dizzy can fluctuate. With manifold vacuum throttle tip-in should be nice and crisp off the line.

Beyond that the next best thing would be to install a “straight up” cam timing set but that’s a pretty involved project. From the factory these things came with the cam retarded 3* (IIRC) and advancing it to 0* or “straight up” will unlock more power.

The problem with removing the EGR on these things is without it you can get pinging under light to moderate acceleration at highway speeds and the EGR also helps with engine cooling.

As for the carb as you push in the gas pedal you’ve start with your primary jets, then the power valve opens up to add more gas, and then the vacuum actuated secondaries come in if your RPMs are high enough. Problems here include blown power valves which will cause an excessively rich idle and poor fuel economy, and gum and varnish in the secondary fuel bowl which renders the secondaries inoperable.

And that’s my .02c.

 

I would not touch the EGR either. Too much risk for pinging. After your trip if you want to strip the entire top of the engine down, put a aftermarket carb on it (It may be easier to also put a aftermarket intake on it with no EGR ports) that could be an option, but will require some experimentation to get it right.

 

Please let the record show that I'm being VERY good and not using this amazing setup to make a cheap joke, even though it would have been very funny.

 

[I am leaning heavily towards just replacing the carb with an Edelbrock 4150. I it makes the difference in 1 mpg over 7000 miles, it will pay for itself.

I think there may have been a fuel filter but someone had the great idea of eliminating it.
I am going to triple check and if I don’t see one, I will add.

Well, no turning back on the EGR/Air Injection delete! :/
Now I’ve just got this mess of vacuum lines to attend to.
So far I haven’t had it on the road with all the elements removed but I do feel the idle is more stable.
That could also be attributed to finally putting some carb cleaner through it.

I really wanted to simplify the set up as much as possible and eliminating the extra pumps and most of the piping seems to be low hanging fruit.
I read about the possibility of pinging, wouldn’t higher octane help with this? Of course, as aforementioned, apparently the lowest octane possible without pinging is an indicator in itself.
I also replaced thermostat with an alternate 180f Motorad.

I’ve read a few things about timing and it seems there’s a lot of incorrect information about the inability to modify. I am assuming this is something with Carb/FI differences?

I also read about going to a “full double roller”, in relation to timing? This would say chain elements to me but it was in relation to the distributor.
I am going to check/adjust the timing as soon as I get back today.
I feel if they are that far off of optimal from the start, it should make a great difference.

I also changed the adjustment for the kickdown armature yesterday. It seems that it wasn’t engaging, I think, because the throttle wasn’t going far enough back.

In an effort to simplify I ended up pulling all this stuff off.
I do not at the moment have the replacement 1” adapter in, but rather just disabled/removed all the elements.
I’ve yet to drive it down the road like this, yet, fingers crossed I haven’t made things worse!

You sir have far more resolve than I, although I can say that with my excitement of having the house on wheels, the typo isn’t really far off from the truth!

I think you nailed it on the thermo controlled switch. There’s 2 sensors on the thermo housing, each with 3 ports.

I’ve got a modification diagram I believe I found on this forum (google searches are blending together at this point) but I haven’t translated the abbreviations/terminology, so I am still I the dark a bit, with that.

Mainly the blue where it says to connect X to X, with no label, I don’t know what those elements even are??

I have to tell you the E90 is fantastic. Even the base model 328i is a great car.
The BIGGEST issue with them is improper maintenance/**** parts.
The VCG will go out, it happens on every BMW.
The Coolant system MUST be bled properly and it MUST have "Blue" coolant. Pentofrost NF is my choice, the are the actual manufacturer for BMW coolant.
There is a TON of information readily available for repair/maintenance.
EVERYTHING is intuitive as far as repair.
You will absolutely look at things from time to time and think "why the hell would that be there....", but when you figure it out, it's magic, and makes absolute sense.
It's a bit of a learning curve from many other platforms but once you get the "zeitgeist" of it, the comprehension growth is exponential.

Feel free to hit me up with an specific questions about pretty much any BMW, anytime!





At the rear of the engine, I found a burnt-up valve (?) that looks like a replacement for the one above it, going to the carburetor?
The one above it appears to have what I assume should be a vacuum connection on the bottom of it, but not connected, so neither of them are doing whatever they are supposed to do.


BTW, I’ve also read that there are people that may have a use for these air pumps so, if anyone has interest in them I would be happy to ship for only the cost of shipping.

Or, if you are in-between Asheville, NC and Seattle, WA, maybe I can drop them off!





RV ENGINE PHOTOS

 

I am leaning heavily towards just replacing the carb with an Edelbrock 4150. I it makes the difference in 1 mpg over 7000 miles, it will pay for itself.
What did you do about all the lines around the thermostat housing?
I think that 4/6 at least can just be blocked off, as they are no longer used .

It's a lot of stuff in just a small area!

I think there may have been a fuel filter but someone had the great idea of eliminating it.
I am going to triple check and if I don’t see one, I will add.

Well, no turning back on the EGR/Air Injection delete! :/
Now I’ve just got this mess of vacuum lines to attend to.
So far I haven’t had it on the road with all the elements removed but I do feel the idle is more stable.
That could also be attributed to finally putting some carb cleaner through it.

I really wanted to simplify the set up as much as possible and eliminating the extra pumps and most of the piping seems to be low hanging fruit.
I read about the possibility of pinging, wouldn’t higher octane help with this? Of course, as aforementioned, apparently the lowest octane possible without pinging is an indicator in itself.
I also replaced thermostat with an alternate 180f Motorad.

I’ve read a few things about timing and it seems there’s a lot of incorrect information about the inability to modify. I am assuming this is something with Carb/FI differences?

I also read about going to a “full double roller”, in relation to timing? This would say chain elements to me but it was in relation to the distributor.
I am going to check/adjust the timing as soon as I get back today.
I feel if they are that far off of optimal from the start, it should make a great difference.

I also changed the adjustment for the kickdown armature yesterday. It seems that it wasn’t engaging, I think, because the throttle wasn’t going far enough back.

In an effort to simplify I ended up pulling all this stuff off.
I do not at the moment have the replacement 1” adapter in, but rather just disabled/removed all the elements.
I’ve yet to drive it down the road like this, yet, fingers crossed I haven’t made things worse!

You sir have far more resolve than I, although I can say that with my excitement of having the house on wheels, the typo isn’t really far off from the truth!

I think you nailed it on the thermo controlled switch. There’s 2 sensors on the thermo housing, each with 3 ports.

I’ve got a modification diagram I believe I found on this forum (google searches are blending together at this point) but I haven’t translated the abbreviations/terminology, so I am still I the dark a bit, with that.

Mainly the blue where it says to connect X to X, with no label, I don’t know what those elements even are??





At the rear of the engine, I found a burnt-up valve (?) that looks like a replacement for the one above it, going to the carburetor?
The one above it appears to have what I assume should be a vacuum connection on the bottom of it, but not connected, so neither of them are doing whatever they are supposed to do.


BTW, I’ve also read that there are people that may have a use for these air pumps so, if anyone has interest in them I would be happy to ship for only the cost of shipping.

Or, if you are in-between Asheville, NC and Seattle, WA, maybe I can drop them off!