help diagnose these symptoms

[NickDawson]

Hey folks,

I've been tinkering on my own quite a bit and learning as I go. The truck is running but there are a few things that make me suspect something is not quite as it should be:



High revs when started and choked - some may recall my idle problem, after cleaning the fuel lines and carb jets, my solution was to increase the mixture screw. I've since backed it off a bit, but its still revving high (by ear), if I lean it any more, it stalls at idl
Soft brakes- they are still effective, but softer than they were a few weeks ago. At a stop light my foot slowly creeps towards the floor. One pump fixes that
Puttering sound when letting off the gas - particularly in low speed/ high torque situations like shifting from 1st into 2nd and 2nd into 3rd. Letting off triggers a rapid two or three "puffft" sounds from the exhaust
Reduction in gas mileage - I haven't filled up yet to do the calculation, but its noticeably burning a lot of gas

So my uneducated guess is some kind of vacuum problem. I've been studying the vacuum gauge on my dash and determined that its probably worthless... it idles on the low end of idle, and dips to "drive" when I accelerate, and "decelerate" when I take my foot off the gas...
But wouldn't a vacuum problem be a proper DX for my break and idle issues?

I felt around the line between the master cylinder to were it meets a metal pipe (i'm sure there are more appropriate terms) I didn't feel any leeks - so what is the right way to trouble shoot vacuum? Do I just yank every hose and replace it? Seems cheap and easy enough. Do I need a vacuum gauge of some kind?

I have not pulled plugs to see if it is in fact running rich. We have a family event this weekend to which I would really like to drive the Rover. I'm worried that once I pull a plug it may never run again. Is there any trick to that?

As always, thanks in advance.

[LRMAN]

This sounds a lot like too rich a mixture. Check the plugs. They are very easy to get out and in again.

The brakes sound scary. I would not drive this truck until you get this fixed. Could be bad brake cylinder, bad seals on master.

[Dino]

High Revs at Start- Could probably mean your carb should be cleaned

[robert wood]

The early NADA SIII had a very wierd distributor that actually retarded the spark at higher vacuum. This was something to do with emission control but IMHO did nothing but make the motor run poorly. Take a look at your distributor and if the diaphragm assembly points forward towards the radiator buy yourself a new distributor with the diaphragm pointing towards the firewall. My personal favorite type is the Ducillier one.

If the distributor has been replaced with one as described above check that the advance/retard is actually working. You can do this by sucking on the tube and seeing if there is movement within the distributor.

If all is well with the distributor and you still get some popping when running downhill the timing may be a bit too far advanced.

Ray

[NickDawson]

Thanks guys

I'd continue to lean it out, but it stalls.

I'll check the plugs and distributor tonight - its not a NADA truck (UK import with a new-to-it 2.5L motor)

[Sputnicker]

I don't think your symptoms are all related to the same root cause.

Fast idle is probably too much choke (you only need enough to idle smoothly and not stall) and/or poor adjustment of the choke cable/linkage.

I doubt that you have a vacuum leak, but you can check by sticking a hose in your ear (no, this is not intended as an insult) and probing with the other end of the hose. You will hear a loud sucking sound when you get close to a vacuum leak.

The brake issue is serious and you should address it immediately. There is another recent thread on this. Look for leaks at all of the wheels and if you don't find anything, it is your master cylinder. A vacuum leak would give you less power assist from the servo (i.i. you need to stomp harder on the pedal) , but if it's going to the floor, you have a hydraulic leak.

My guess on the exhaust noise is either an exhaust leak or too rich a mixture. What you are hearing is unburned fuel igniting after it enters the exhaust system.

By the way, the mixture adjustment on the carburetor only works for the idle circuit. The mixture at speed is controlled by jets and is not adjustable (without changing jets). A rich mixture can also be caused by a carburetor fault like a leaky needle and seat or float level too high. An old-school, low-tech way to check mixture at speed is to get the engine nice and warm (make sure the choke is off), run at speed for a while (mile or two), turn the engine off (don't let it idle), coast to a stop (in a safe place) and pull the spark plugs. If they are fuzzy and black, or slightly damp and black, it is too rich. Optimal mixture is a very light brown, or no noticeable deposits on newer plugs.

Good luck.

[NickDawson]

I don't think your symptoms are all related to the same root cause.

Fast idle is probably too much choke (you only need enough to idle smoothly and not stall) and/or poor adjustment of the choke cable/linkage.

The brake issue is serious and you should address it immediately. There is another recent thread on this. Look for leaks at all of the wheels and if you don't find anything, it is your master cylinder. A vacuum leak would give you less power assist from the servo (i.i. you need to stomp harder on the pedal) , but if it's going to the floor, you have a hydraulic leak.

My guess on the exhaust noise is either an exhaust leak or too rich a mixture. What you are hearing is unburned fuel igniting after it enters the exhaust system.

Good luck.

Thanks Sputnicker
I'll admit, I was hoping they were related. All the the issues with the truck started on the same day.

I'll continue to work on the idle adjustment - but I'm guessing that was not that appropriate fix for my stalling problem. I suspect the jets are correct since it ran for 4 weeks with no problem.

Interestingly, the choke control used to pull all the way out, where I could see the cable - in the last week its been much tighter and more effective and my cold start light is working again.... regardless, having already tinkered with the idle mixture setting I'm guessing that it has something to do with this.

As for the breaks - I've kept my eye out for leaks - nothing around the wheels - would I see it without taking tires off?

Here's my usual question: how complicated is break work/ master cylinder? I'm constantly worried about getting into a project and rendering it undriveable

again, someone remind me this is what I signed up for and again please leave out the part about UK imports

[LRMAN]

Brake work is not complicated. A simple pump pressurizes the lines that in turn expands a hydraulic cylinder pushing brake shoes against a machined drum.

You could easily have a faulty flexible brake line. I have seen symptoms similar to yours from that. It could also be a bad brake cylinder or master cylinder. If one part of the brake system is failing then other parts are going to soon also. Don't risk your life on some basic parts.

Don't try to fix what you have. Replace all wheel cylinders, All flexible brake lines, all pads and either a new or well rebuilt master cylinder. Having the drums turned or replaced is a good idea. Flush everything and then fill and bleed. I think you will notice a difference.

If anything I have said seems complicated you may be better off trusting this to someone more experienced.

[bmohan55]

Nick, I just did all my brakes, it wasn't that hard and very educational. Replaced the Master cylinder and two wheel cylinder, turned the drums (replaced one) and new pads. Our hosts have a great "how to" in their tech section on brakes. Check the rubber lines too.
Go with a new master cylinder if needed as it's very difficult to rebuild one correctly.

[NickDawson]

Does replacing the master cylinder require replacing the servo too?
The rest seems like a stomachable price and after reading the green bible last night an approachable project (although I'm still fairly unsure about draining and bleeding the system)

I'm also not 100% sure there is a leak ... I drove around last night and put them to the test... 30mph to a dead stop = worked fine several times...
foot on the break on a hill for several minutes = truck never moved, but my foot did very slowly creep down... Although I guess in the end its sill to try and talk myself out of something that could be a safety issue.

Took it in for Va state inspection last night, secret thought is that having someone else drive it might help confirm the diagnosis. I asked them to pull all 4 wheels while on the rack, regretting that I won't be there to see it, but for $20 its worth my time to check each one in the 100 degree heat wave we are having. Of course, this assumes that they would have a clue what they are looking at.

I'll keep everyone posted - thanks for the tips.

The idle problem is still lingering, but as near as I can tell, its only manifestation is poor gas mileage

[bmohan55]

I did not need to do the servo. As I understand it IF the MS has leaked for a long time then the brake fluid may have degraded the diaphram in the servo. Mine still sealed well.

I too was very unsure of doing this job as I'm as green as you but believe me, take your time, do one brake at a time (so you could look at the other to see how it goes back together) and you'll be fine. No more than a six-pack job!

[rbonnett]

I'll just second about the brakes. I just finished redoing mine. New MC, 1 new WC, new shoes on the front, had all 4 drums turned.

The only part that was a headache for me was bleeding the system. I finally gave in and borrowed a power bleeder - which made even that pretty much a snap. I was lucky that the lines were farily new, so I didn't have corrosion and seizing for what I had to disconnect.

Get good instructions, the GB is good. I also found the Hayne's Restoration helpful - nice step-by-step with pictures. There was also a post here with a very clear write-up - maybe someone can post the link to that.

Things I learned:
- Don't assume the shoes and springs are correct now. Between them, mine had jsut about every possible thing wrong, switched shoes, misconnected springs, one WC with one rubber boot in crumbs. Check what you see against the manuals.
- Use one intact wheel as a reference as you do the others - assuming you have one :). By the time you get back around to it you'll know what you're doing.
- Bench bleed the master cylinder
- Be methodical and take your time. I found it all mechanically simple but got in my own way at times trying to shortcut getting the new springs and shoes on.


You'll do fine. And you'll get to laugh when your friends complain about the price of a brake job :)

[NickDawson]

Update:
Got a 2nd opinion from a local shop. They have an older guy who had not seen a Rover, but knew carborated engines inside and out... was worth the DX help for $30 (and a failed state inspection).

Master Cylinder is toast - he pulled the tires and I did get a look, new wheel cylinders and the lines look relitivly new too. I know this group favors replacing entire systems, but I'd like to start with the cylinder and see where that gets me for a few months.

Some have mentioned a "bench bleed" of the cylinder - can anyone elaborate? I'd prefer not to bleed the entire system if it can be avoided.

Carb - his guess is a stuck float. Some of you suggested that as well, so it will be my next place to tinker. While I'm waiting on the MC to arrive, I'll take the carb off and see what I can discover. Anyone want the box of left over parts when I'm done?

Exhaust leak - some may recal an early thread where I mentioned a little bit of coolant right under the thermostat housing. I'm hopeful that its just a gasket (is there one) under the thermostat, but I guess it could be the head gasket too... its an inspection issue so I have to get it fixed but I'm really not pleased at the prospect off a blown head gasket. Going to start with the thermostat.

He also saw two leaks while up on the lift - one from the xfer case (thinking its actually overfill from the spedo cable) and the rear diff... I had not seen that one myself. Whats the best way to approach a leaky diff?

Thats about it... guess I know what I have in front of me. Any tips on any of the above operations?

edited to add: ordered the MC and some gaskets today from Steve at RN - got some awesome advice on bench bleeding. He also recommended bleeding the entire system. I've moved past anger, through trepidation and into excited acceptance... this might actually be fun?

[rbonnett]

I summary: bench bleeding is making a closed circuit from the outlets of the MC back to the reservoir. Then cycling the MC to run fluid through until no more air returns up the line to the reservoir. If you Google bench bleeding you can find any number of detailed explanations and videos.
The classic method is to clamp the MC in a vise on your workbench and use a large screwdriver or similar to work the piston in the MC. I did mine mounted in place and used the brake pedal to do it, which worked.
You'll want to bleed the brake system regardless, some air is going to sneak into the lines anyway. Bench bleding the MC will make it quicker, easier and more reliable than not.

[NickDawson]

Well, enter concern...
I ordered the Series III dual circuit MC, but now that I (think) I know what I am looking at I only see one break line
http://farm3.static.flickr.com/2574/3816274700_4c07f67270.jpg (http://www.flickr.com/photos/nickdawson/3816274700/sizes/o/)
Plus that resovior doesnt look a thing like this one that I ordered (from work when I didn't have the truck to look at):

http://www.roversnorth.com/store/images/Product/medium/PLC454.JPG
http://www.roversnorth.com/store/p-4758-master-cyl-88-dual-power-series-iia-iii.aspx

In looking at the store - is this the one I need to order? http://www.roversnorth.com/store/p-2448-master-cyl-early-cv-type-series-iia-iii.aspx

Did someone use the series III 109 MC in my frankenrover? Or were single circuits the norm for UK spec IIIs?

I see where the break line goes into a T ... are there fittings and more piping I can buy to make it into a dual circuit? Is there anything else involved in that?

While I'm wallowing in it - another reason it failed state inspection was for an exhaust leak... assuming I have to get at the gaskets on the manifold, it looks like these bolts are almost welded on from heat and that the exhaust pipes are rusted around the edges. ... what does that mean? New manifold take offs? (detail if you click the pic)

http://farm4.static.flickr.com/3539/3816274746_b3bdbb5ceb_m.jpg (http://www.flickr.com/photos/nickdawson/3816274746/sizes/o/)

[rbonnett]

Wow. I would have thought a '73 would have dual circuits. I assume it was a UK difference, cuz I can't imagine anyone converting from dual to single circuit. Looks like that is the MC you want to exchange for. The big difference for you is just one circuit out of the MC to bleed on the bench.
People do convert from the older single to dual circuit systems - never done it. Maybe someone else can provide some detials of that. One big diff is a valve fitting that cuts out one circuit if it loses pressure.

[LaneRover]

See what ya get from listening to me! Sorry if I helped lead ya down the wrong path!

To convert to a dual system You need to separate the front brakes from the rear. The factory did this on the right side on the frame near the oil filter (if my memory serves me correctly) There is a part that does that and its name escapes me. You'll also have to run an additional line from the brake dual MC to that splitter thingy. I believe you can leave the rest of the system alone.

Brent

[Sputnicker]

I'm also very surprised to see a single-circuit master on a car of that vintage. Dual circuits have been required in the US since 1968 and I thought most other countries had also adopted them by then (the Swedes were the first to use them). It may be some kind of kluge by a previous owner.

The single-circuit master that you provided the link for is definitely not correct - note that the 2-bolt flange is 90 degrees different (vertical instead of horizontal) and will not bolt up to the servo. I guess your only alternatives are to try to find a replacement for what you have (start calling suppliers, or looking at British web-sites), or converting to a dual system, which will be a pain, but the parts are available and it will be a safer vehicle when you're done. There's also the risk that it may not pass a safety inspection (by a very observant inspector) in some states with single-circuit brakes.

On the exhaust, if it's leaking at the manifold, you have no choice but to start unbolting things and having a look. Use some penetrating fluid, bend back the rusty lock tabs and go for it. The cast iron on the manifold is very thick, so they can be quite rusty on the outside and still work perfectly. If there aren't any cracks or other defects, it should be fine. When you order the manifold gasket, you may want to also get the flange gasket for the bottom (just in case) and new nuts, bolts/studs and washers. You are likely to break and/or mangle a few.

Good luck.

[SafeAirOne]

Count those lines first! My 1973 UK-spec 109 also has the single circuit master cylinder--the exact same one you pictured. I won't mention the copper brake line used throughout the entire system...

Sputnicker is right, you need to make sure you get the single-circuit MC with horizontal mounting tabs (where it fastens to the brake booster (servo). I've replaced my MC in the past so the MC is certainly available, though I can't recall where I got mine. I'm willing to bet that our hosts have them--Just describe it accurately to them.

[NickDawson]

Count those lines first! My 1973 UK-spec 109 also has the single circuit master cylinder--the exact same one you pictured. I won't mention the copper brake line used throughout the entire system...


The green bible clearly shows single and dual systems. So I'm guessing it was either vintage or country specific. I'm in a debate between conversion and just replacing with another single... as the issues pile up I have visions of my truck not running for a year... I'd kinda like to just get it fixed.

Sputnicker thanks for the info on the exhaust... My number one order of business is getting the breaks working and the carb tuned, but its clear that I'll have to do something about the leak before it will pass inspection, not trilled about it, but glad to know that the parts might be salvageable.
______________
edited to add:
Guess who is going to a dual circuit break system? Our awesome hosts are helping by making some lines and as always Steve has made the conversion sound easy :D

The plan is to run a new line to the back junction from the new master. Then I'll run a short piece of new line from the MC down to a 3 way junction that splits the existing front front lines.
It actually does sound easy enough.


In case anyone else ever runs into this - apparently there was a factor option for the early III 88s where you could order a power assisted single circuit break system. Not sure why someone would chose that over the dual system, but there it is. That MC is not something that RN stocks.

[SafeAirOne]

edited to add:
The plan is to run a new line to the back junction from the new master. Then I'll run a short piece of new line from the MC down to a 3 way junction that splits the existing front front lines.
It actually does sound easy enough.

Easy and much safer. Good choice.

[kevkon]

Definitely bleed the whole system, I'd recommend contacting http://speedbleeder.zoovy.com/ to see if their speed bleeders are available for the rover. Definitely makes brake bleeding a snap with one person.
Have you confirmed that the ignition and cam timing is correct?

[NickDawson]

Definitely bleed the whole system, I'd recommend contacting http://speedbleeder.zoovy.com/ to see if their speed bleeders are available for the rover. Definitely makes brake bleeding a snap with one person.
Have you confirmed that the ignition and cam timing is correct?

Those speed bleeders look very slick. Still not sure I fully understand the entire process enough to warrant adding something new, I plan to enlist the wife to make it a 2 person job. She can pump the breaks and I'll look for bubble free fluid.

As for timing - no, I haven't had a chance to think about that. All signs point to the carb at this point, I'm going to take it off tonight and make sure the float isn't stuck.

[scott]

if you're flushing start with a short hose off the bleeder valve into a quart jar, pump until you've run your resivor dry at least three times for the first (left rear on an 88 lhd) then discard the contents of jar. replace short hose with a long enough one to reach from the bleeder valve to the resi. clip the end of the hose into the resi so that its below the the surface. get a beer. sit behind the wheel and start pumping. pump until you see no more air go through the hose (oh year use clear hose) that runs right past you. repeat for each wheel. depending on how fast you drink you may need to wait a while before testing

[kevkon]

The speed bleeders work well. Basically it's a check valve so you don't have to keep loosening and tightening the bleeder. You would be surprised at how little air in the system is required for there to be excessive pedal movement. Improper brake adjustment will also give you the long pedal travel.
You really should check the timing before any carb adjusting because you may end up getting further away from where you want to be.

[NickDawson]

get a beer.
I like this plan!

Do I need to actually clamp off the other 3 lines, or is simply opening the bleeder valve on one break cylinder at a time sufficient?

[scott]

I like this plan!

Do I need to actually clamp off the other 3 lines, or is simply opening the bleeder valve on one break cylinder at a time sufficient?


leave all bleeder valves closed except one. start with the one furthest from the mc and work towards the closest. use break line legnth not straight line. on my 88 lhd it is lr, rr, lf then rf.

after putting on the clear tube open the valve and leave it open. don't forget to open the beer. after the little air bubbles stop pass'n you by stop pump'n and you can leasurly go and closed the bleeder valve, leave the one end of the tube in the rezi and move the other end to the next valve, hook it up, open the valve, check rezi level, get another beer and go back to pump'n the brake pedal. this works for the clutch too but it's harder to kill a six pack.

[bmohan55]

pm'ed ya

[NickDawson]

File this under the: "hows it work" section rather than "hes just crazy enough to risk his life on something stupid" section...

Could a dual circuit master cylinder be used in a single circut system, by either capping off the 2nd outlet our using a Y fitting?

Also, along the lines of Kevkon's suggestion - whats the best way to check timing? I see $30 timing lights on Amazon... but not sure how that whole ignition system works.
edited to add: just found this awesome post from Jeff on using a timing light
http://www.roversnorth.com/forums/showthread.php?t=6298&highlight=timing+light

Seems like an easy thing to check

[kevkon]

It is easy to check Nick and if you don't want to buy a strobe light you can go to any repair shop and ask them to check it. This will tell you whether the timing is correct, whether the advance is working, and whether there is any indication of a worn timing chain or gears. I'd start here before playing with the carb, especially on an older vehicle.

[NickDawson]

update:
The new MC arrived already bench bleed - suspect someone at our hosts took pity on me... but I repeated the process to learn...
Its installed - the old one was definitely toast. Still waiting on some breaklines from our hosts to complete the job.

I also installed a new thermostat and gasket - fingers crossed thats where the coolant on the block was coming from.

Then I turned my attention to the carb... for the life of me I cannot get the damn thing off the intake...I'm sure with some more time and patience it will come, but I'm going to take Kevkon's advice and check the timing before I do anything else. ... although timing still doesnt answer why the idle problem started after running fine for 4 weeks.

If it comes down to it, I've heard that you can turn an old carb in for a partial exchange on a newly rebuilt one - do our hosts offer that? I'm determined not to "buy my way out" of the problem...but if push comes to shove, I'd rather drive again this summer than tinker for 4 weeks.

[NickDawson]

Fingers crossed that its a timing issue...

I got the carb off and cleaned it every what I could find... if there was a screw, I unscrewed it, if there was a hole, it got sprayed...if there was a valve it got enough cleaner to light up a bonfire.

Admittedly I was surprised that the truck ran again once I put it back together... it might actually be running better, but the cable that connects the throttle linkage to the throttle on the carb seems to be getting stuck a little open. Maybe I cleaned it too much! Anyone know the best way to lubricate that throttle and cable?

Back to timing and Kevkon's point - could inaccurate timing cause my backfire and occasional dieseling? Could timing cause it to run rich (or similar symptoms)?

Still awaiting the break lines from RN - hope they account for the different size orifice on the new MC and the old break lines :D

[kevkon]

Nick, improper valve or ignition timing will cause the combustion sequence to become out of sync. If the spark or ignition occurs too early ( advanced) or too late (retarded) then the fuel mixture will not yield it's optimum potential energy. Also too much advance will cause ignition to occur before the valves are closed causing the backfire. One advantage to using a timing light is that you can observe any fluctuations in the timing which may indicate a vacuum leak or a problem with the timing chain or valve train.
As for the cable lube, I like to use the motorcycle cable lube products such as Tr-Flow.