Increase throttle... Engines wants to stall?

[RoverForm]

i thought i saw a thread on this topic.

after the trucks warm, and the choke is pushed all the way in, when i press the gas pedal, the engine starts to stall.

the only solution is to have the choke pulled out halfway, high idle, then it doesn't attempt to stall.

thoughts?

[Nium]

Which carb you got? Points been adjusted recently? Year and model of rover?

[siii8873]

could be a vacuum leak

[RoverForm]

'66 IIa 88" 2.25 petrol RHD
solex carb

points def not adjusted recently
started yesterday halfway back from the brickyard hauling half a ton of leveling sand

[Nium]

IMHO I'd say adjust the points and check the timing and see if that helps.

[singingcamel]

My money is on the carb, hence , needing to drive with the choke out.
Check for leak at the base plate of the carb, retorque the base plate and adjust the carb.
I would also adjust the valves and tune it up.
www.singingcamel.com (http://www.singingcamel.com)

[mongoswede]

If the truck needs the choke on to run then thats a classic indication of a vacuum leak or a lean running condition...which could be a bad gasket or a clogged jet or passage. The choke chokes off the air supply to the carb so it gets more fuel....so with the choke on you are richening the fuel mixture.

[daveb]

could be the accelerator pump is not working. with the engine off, look down the carb while somebody pushes the gas pedal to the floor. You should see a stream of fuel shoot down the throat of the carb. If not, either the linkage to the accel pump is bad or the pump diaphragm is shot.



i thought i saw a thread on this topic.

after the trucks warm, and the choke is pushed all the way in, when i press the gas pedal, the engine starts to stall.

the only solution is to have the choke pulled out halfway, high idle, then it doesn't attempt to stall.

thoughts?

[jimrr]

it's usually the carb, floor the gas and the engine gags and will stop without feathing the pedal.

[gudjeon]

I would check for a line blockage, vacuum leak, and accel pump. After that, the fuel pump output. I have seen many seemingly big problems on old motors caused by these.

[NickDawson]

IMHO I'd say adjust the points and check the timing and see if that helps.

Sounds like points and timing to me too.
If they haven't been adjusted in a while, grab a new set and a new condenser too - $15 well spent.

[mongoswede]

in summary: its probably something under the hood (sorry...bonnett) thats causing the problem :D

[Terrys]

I agree with others; sounds like carb. Maybe a bunch of crud in th bottom of the bowl, slowly plugging the main jet. Doesn't sound like accel. pump, though the jet in the accel. pump is tiny (34ICH notorious for plugged accel jet body) Points closing up can mimmick this to some degree, but the choke hint kinda rules points out. Sounds like a 2 Six pack evening in the garage with a few good mechanics to kibbitz. I love a good problem with friends. We may not always fix it that night but we all feel good about it, and everything else too.

[RoverForm]

great input. i appreciate the replies.

today i went out and removed the timing cover on the fly wheel and the dizzy cover. was going to mess with the timing per page 32 in the green bible, but realized i didn't have a 12v test light, nor had enough spare bulbs/bits to make one. saving that for another day... what brand/type of test light do you all use for timing? the GB shows just a simple bulb with two wires?

i did start the beast up, let it run with the choke 1/2 way out for a good ten minutes to get warm, then pushed the choke in and hit the gas. no sputter, no attempt to stall.

i didn't have time to take her around the block and test under vehicle load... but i did have a look in the carb and the inner intake is completely black. perhaps it's time for a tune up?

but why didn't it try and stall today when i hit the gas?

[gudjeon]

I use an el cheapo multi-meter set on Ohms to do the work of a test light.:thumb-up:

[jimrr]

I hope that's a miss print that u pulled the timeing cover!!!!!!
set the float level, the points, fuel filter and a serious check for vacume leaks and it'll prob run fine.

[mongoswede]

but why didn't it try and stall today when i hit the gas?

perhaps you have junk in your carb that is floating around and blocking a passage and then unblocking. doesn't take much to clog a jet.

[Nium]

The low tension lead is probably bad and you jiggled it when removing the distributor cap allowing it to make a more solid connection for now. Before troubleshooting fuel issues make sure the low tension lead is sound, the points are adjusted properly, the timing is set correctly, the distributor cap is in good condition, the rotor is in good shape, the sparkplug wires are in good shape, and the sparkplugs are in good condition. Set the points before checking timing. Poor spark easily leads to poor running. Ignition components fail before carbs go out of adjustment.

Make sure the low tension lead is in good condition.

If the ignition is sound go after fuel delivery system as the culprit, never the other way round. My $0.02

[Terrys]

the only solution is to have the choke pulled out halfway, high idle, then it doesn't attempt to stall.


How does pulling the choke out fix a bad low tension lead?

[mongoswede]

How does pulling the choke out fix a bad low tension lead?

Weeeelllllll. A lean mixture is harder to ignite...but id say that's a stretch

[RoverForm]

How does pulling the choke out fix a bad low tension lead?
no idea. and i'm not saying i fixed anything. just that, pulling the choke out a bit prevented me from having to feather the gas, and got me home without having the landy stall out in the left hand turn lane.


I hope that's a miss print that u pulled the timeing cover!!!!!!
i probably just used the wrong jargon. i'm not up to speed on all the proper names of components. i removed the cover on the right side of the flywheel that exposes the 6 and 3 degree timing markers.


I use an el cheapo multi-meter set on Ohms to do the work of a test light.:thumb-up:
can you explain this process?

[jac04]

I hope that's a miss print that u pulled the timeing cover!!!!!!
It's a required step to set the timing on the old IIAs. You need to know where the flywheel is. Remember that not everyone has a pointer and marks on the crank pulley.

[Terrys]

no idea. and i'm not saying i fixed anything. just that, pulling the choke out a bit prevented me from having to feather the gas, and got me home without having the landy stall out in the left hand turn lane.
My 'question' wasn't directed towards you RoverForm, but to Nium. You gave a hint sufficient to make me believe your issue is carb related, not primarily an ign. issue. If you had a partially plugged main jet, you're essentially starving for fuel by going lean. Pulling out your choke enrichened the mixture. If your low tension lead were faulty you would get a bucking like flicking your key on and off rapidly, and while point gap has alot to do with how well an engine will accelerate, your choke comment has me leaning more towards the carb as opposed to the distributor.

[Nium]

RoverForm,
After adjusting point gap it doesn't hurt to check timing but it's not always necessary to adjust the timing, if you are getting spark knock on acceleration then the timing is to advanced and should be adjusted.

To check static timing I use a standard 12V test light available at any auto parts store. The method I like because it doesn't require having the ignition switch in the on position.


disconnect the external low tension lead from the internal distributor low tension lead (the wire from the coil to the distributor disconnect at distributor)
attach the alligator clip of the test light to the spade connector of the distributor low tension lead and have the dizzy cap off
place the needle of the test light in the non-grounded side of the battery so it's sticking straight up from the battery making the light easy to see from the crank handle when at the front of the rig
rotate the engine with the crank handle or big wrench on the crank pulley nut or by pulling on the fan belt (it's easier if you remove the spark plugs but I usually don't) until the rotor is almost pointing at cylinder #1 position. The test light should be on because the points are closed.
Slowly rotate the engine until the test light just goes out. The points are now open. Check the timing marks. For most it seems 6 BTDC works the best. With modern fuels the recommendations of the Green Bible may not be accurate anymore. If you're running 87 octane or lower 6 BTDC is a good place to start.
Static timing is a starting point. Get the engine running and you can fine tune the timing by adjusting it by ear. Then go back and check where it runs the best by the static timing method and make a note of where the timing marks are for future reference.
To use a mutlimeter attach it the same way as the test lamp



resistance setting (ohms). No resistance reading (or very low resistance) and points closed. Infinte resistance reading points open
DC voltage setting. Reading of battery voltage points closed. Reading of no voltage points open.



TerryS,

The things that led me to suggest the low tension lead as a possible suspect



That the rover in question is a 1966 which means the distributor is probably a Lucas 25D4 which is notorious, in my experience, for the low tension lead breaking.
The title of the thread "Increase throttle...Engine wants to stall". The conductor of the lead will break inside the insulation causing the lead to open when the accelerator is depressed and the distributor advances. Then the engine stalls the accelerator is lifted the distributor stops advancing and the wire is unsquished because the distributor stops advancing the spark and continuity of the lead is reestablished. Thus mimicking fuel starvation.
The second line of OP "after the trucks warm, and the choke is pushed all the way in, when i press the gas pedal, the engine starts to stall". Same symptom as title.
As for the need to choke it and keep a high idle led me to suggest to look at the points being out of adjustment and not opening enough to cause sufficient spark and that just enough current was passing through the break in the low tension lead to keep a weak spark going.
Post #4 by RoverForm the statement "started yesterday halfway back from the brickyard hauling half a ton of leveling sand" broken low tension lead issues for me have always happened all of a sudden out of the blue.
Post #14 by RoverForm where the statment that the truck ran well again after nothing more was done then removing the distributor cap, timing mark cover on the flywheel, and (I assume) the air cleaner. Would seem to point at the distributor as the culprit because in removing the distributor cover the external low tension lead of the distributor was probably shifted causing the, internal to the distributor, low tension lead to shift enough to seem to cause the issue to go away. Till it gets flexed enough to cause the break in the wire to open again.
That it's a Solex carb on the rig so it's not gonna be a Zenith warp issue. I haven't worked with Solex carbs but I believe I've heard their reliable and don't recollect they're prone to warping at the base where they bolt to the manifold.

I've torn apart carbs, removed fuel filters, checked the pick up tube in the gas tank while completely ignoring the ignition system to finally realize it was the low tension lead causing all sorts of symptoms. Now I will always check the ignition system is in good working order before I look at any of the fuel delivery system.

I am not trying to say it can't be something else just that the ignition system is easy to verify as being in good working order and is easily accessible because all the parts of the ignition are consumable and designed to be replaced.

And after that marathon post it'll probably just be water in the gas or RoverForm has a different dizzy then the 25D4, and please if anyone feels what I wrote is in error I don't claim to know anything and would rather someone that has a different idea or insight help out RoverForm and provide me the opportunity to learn more. My feathers don't get ruffled and I don't care if you call me a knuckle dragging monkey that couldn't find the end of a stick. Heck I don't even know who Emily Post is.:thumb-up:

Cheers!

Picture of alleged culprit Low Tension Lead of the Lucas 25D4 distributor
http://farm3.static.flickr.com/2486/4108068104_0f4f0a8f88_m.jpg

[Terrys]

I don't disagree with anything you've said, and have found the internal lead has failed on lots of (brit) cars; not just LRs. Also the internal breaker plate ground wire breaks. That said, I still prefer the 25D to the 45D.
However, the reason I look to the carb as the culprit (or, if you prefer, look away from the low tension lead theory) is that Rover Form stated that with the choke partially out, the problem goes away. If it were a broken lead, the problem would still exist, because the advance unit is still functioning, even at a high idle. My only recollections of Solex issues were on Porsche work and I don't remember anything noteworthy on Landies. The Zenith Warpage issue is more related to the late ones, as the early ones don't seem to have ever suffered. I'm growing to hate the 34ICH Weber less as I fuss with them more. The Carter YA and YB are still my favorites and Rochesters are always good, provided they don't need rebuilding. Carb Doctor hoarded all the remaining rebuild kits.

[RoverForm]

Ok so I've ben out of town for awhile. Had a trip to Indonesia recently. Unfortunately I only saw two LRs while there.

Anyway, here's the video footage of the current issue I'm having:

Press the gas, engine tries to stall...

http://www.youtube.com/watch?v=hlkyG3EGgH4

[RoverForm]

well this is embarrassing, however, i feel as though i need to lay this issue to rest.

it's been over a year since i first posted on the problem of my engine stalling issue. just wanted to report that it was the valves. 4 and 8 were adjusted properly at .010, but all the rest were too tight, and it was running way too rich.

it is now resolved, she's purring like a kitten as they say, and the idle is clean, soft and smooth.

thanks to everyone who made contributions!

http://farm8.staticflickr.com/7041/6778861754_bcd5cf8d33_z.jpg

[73series88]

glad you were able to fix it
that was an isue for a long time if i remember correctly
purrs like a rover.
aaron