Engine Miss When Climbing Hill

mensoft · December 26, 2013

Hi AL Experts ,

Please give me a quick answer why this can be happen ?

my car running all smooth without no issue at all. but now from few days when it climbing a hill engine is missing . even if its in first gear and accelerate.

why this can be ? its only if car have to climb a hill .

Car is Lancer A72 (1976) .

Davy · December 26, 2013

Could be several reasons IMO... If the miss is sharp, it could be due to an ignition fault, Check the following components:

- Distributor - check and clean the contact points and rotor, check capacitor

- Spark plugs - check if they need to be replaced or clean

- High tension leads (plug wires) - Clean wire insulation and check for damage. Run the engine and check if each lead works as it should.

If all of the above does not solve the issue, we can move on to the fuel system (check fuel filter and pump).

MasterDon · December 26, 2013

Yes check fuel lines and pump.Most probably a faulty pump that can't handle the extra load when going uphill because of an air leak.Change the diaphragm if possible or the whole unit.

Or it could be something very simple.My Magnette started to misfire in a similar manner when going uphill...turned out the ignition coil wire was losing contact in an incline.

mensoft · December 26, 2013

On 12/26/2013 at 9:35 AM, MasterDon said:
Yes check fuel lines and pump.Most probably a faulty pump that can't handle the extra load when going uphill because of an air leak.Change the diaphragm if possible or the whole unit.
Or it could be something very simple.My Magnette started to misfire in a similar manner when going uphill...turned out the ignition coil wire was losing contact in an incline.

Hi Don.

Some yours back i had to change the ignition coil .

now its not a original wet coil. its a dry ignition coil (brand call new era) looks like this.

When i purchase as they told its not stop working like dry coil when it get heat. any way I think this coil is in good working condition.

I would like to try the first option. can try DIY on this ? how to locate the fuel pump ?

MasterDon · December 26, 2013

On 12/26/2013 at 11:19 AM, mensoft said:
Hi Don.
Some yours back i had to change the ignition coil .

now its not a original wet coil. its a dry ignition coil (brand call new era) looks like this.

When i purchase as they told its not stop working like dry coil when it get heat. any way I think this coil is in good working condition.

I would like to try the first option. can try DIY on this ? how to locate the fuel pump ?

Your ignition coil itself should be OK.I have a couple of cars converted to dry electronic coils aswell and they rarely go bad.What I meant was the big wire coming out of the coil.Check if it comes loose when in an incline.

Don't go straight for the pump.Check the basics first like loose wires and contacts.Try taking a mechanic on a trial run on a hilly road and see what he thinks.You can also ask him to jack up the whole front of the car and moniter the fuel pressure.If it drops then it's definitely the pump.I'm not sure wether these old lancers came with mechanical or electric fuel pumps but eitherway it should be somewhere in the engine bay or at the rear close to the fuel tank.follow the 'fuel in' line from the carb and you should find it.

Davy · December 26, 2013

The 4G33 engine comes with a sealed mechanical pump and it's located just next to the distributor. The fuel pump has a linkage to the valve body, touching the camshaft and pumps fuel as the camshaft turns. So it cannot be repaired and will have to be replaced as a whole unit if proven to be faulty. The original pump looks like this (appearance could be slightly different):

Like I mentioned before, if the miss is sharp (sudden jerk), then it's likely that the fault is with the ignition system, if it's soft (gradual loss of power and then picking back up), then you might be looking at a fuel system fault. Just observe what kind of miss it is and start looking into the respective area.

mensoft · December 26, 2013

Hi Done and Davy,

Thanks you both for the info. I too did a Google for the fuel pump. davy. yes your correct its looks like this.

Exactly this

I can locate the item also my engine is G11B.

So is it possible to repair the pump or replace it ? are these new pump available to buy from spare part shop or rare ? matching for my engine.

can i just remove the pump and replace myself or is it a big job ? is there any timing has to mach when it fix back if i remove the pump ?

if you could share a YouTube link related to this will be much helpful

Edited December 26, 2013 by mensoft

mensoft · December 26, 2013

On 12/26/2013 at 3:10 PM, Davy said:
The 4G33 engine comes with a sealed mechanical pump and it's located just next to the distributor. The fuel pump has a linkage to the valve body, touching the camshaft and pumps fuel as the camshaft turns. So it cannot be repaired and will have to be replaced as a whole unit if proven to be faulty. The original pump looks like this (appearance could be slightly different):

Like I mentioned before, if the miss is sharp (sudden jerk), then it's likely that the fault is with the ignition system, if it's soft (gradual loss of power and then picking back up), then you might be looking at a fuel system fault. Just observe what kind of miss it is and start looking into the respective area.

On 12/26/2013 at 1:12 PM, MasterDon said:
Your ignition coil itself should be OK.I have a couple of cars converted to dry electronic coils aswell and they rarely go bad.What I meant was the big wire coming out of the coil.Check if it comes loose when in an incline.
Don't go straight for the pump.Check the basics first like loose wires and contacts.Try taking a mechanic on a trial run on a hilly road and see what he thinks.You can also ask him to jack up the whole front of the car and moniter the fuel pressure.If it drops then it's definitely the pump.I'm not sure wether these old lancers came with mechanical or electric fuel pumps but eitherway it should be somewhere in the engine bay or at the rear close to the fuel tank.follow the 'fuel in' line from the carb and you should find it.

Hi Don and Davy,

Thanks you both for the info. I too did a Google for the fuel pump. davy. yes your correct its looks like this.

Exactly like this

I can locate the item also my engine is G11B.

So is it possible to repair the pump or replace it ? are these new pump available to buy from spare part shop or rare ? matching for my engine.

can i just remove the pump and replace myself or is it a big job ? is there any timing has to mach when it fix back if i remove the pump ?

if you could share a YouTube link related to this will be much helpful

Edited December 26, 2013 by mensoft

Davy · December 28, 2013

Cannot repair the pump. I repeat, cannot repair the pump. It has to be replaced as a whole unit as I have mentioned above.

Yes, these pumps are available recon or brand new at Panchikawatte. A brand new one cost me about Rs. 3500 back in 2010.

About installation: Yes, you can just take out the old pump and fix the new one. Go through pages 44 - 49 of the fuel system workshop manual (Download it from here). Removal and installation steps are clearly illustrated in the manual.

It looks like you are certain that the miss is due to a failing fuel pump, did you perform the other, (much simpler) checks before going ahead and opting to replace the fuel pump? If I were you, I'd leave the fuel pump for later and check up on them first. Just my 2 cents.

EAP · December 28, 2013

On 12/26/2013 at 3:32 PM, mensoft said:
Hi Don and Davy,
Thanks you both for the info. I too did a Google for the fuel pump. davy. yes your correct its looks like this.

Exactly like this

I can locate the item also my engine is G11B.

So is it possible to repair the pump or replace it ? are these new pump available to buy from spare part shop or rare ? matching for my engine.

can i just remove the pump and replace myself or is it a big job ? is there any timing has to mach when it fix back if i remove the pump ?

if you could share a YouTube link related to this will be much helpful

Hi Mensoft

Please refer to Ebay item number 130889093805. I believe its NEW and the same Pump you are looking for? and selling price is £23. Got a friend who is in the UK and I wouldn't mind asking him to help you to send it to SL.

Let me know

mensoft · December 30, 2013

On 12/28/2013 at 5:26 AM, Davy said:
Cannot repair the pump. I repeat, cannot repair the pump. It has to be replaced as a whole unit as I have mentioned above.
Yes, these pumps are available recon or brand new at Panchikawatte. A brand new one cost me about Rs. 3500 back in 2010.

About installation: Yes, you can just take out the old pump and fix the new one. Go through pages 44 - 49 of the fuel system workshop manual (Download it from here). Removal and installation steps are clearly illustrated in the manual.

It looks like you are certain that the miss is due to a failing fuel pump, did you perform the other, (much simpler) checks before going ahead and opting to replace the fuel pump? If I were you, I'd leave the fuel pump for later and check up on them first. Just my 2 cents.

Hi Davy ,

Thanks for your advice. i just did few diagnosis my self . i replace each vacuum lines in the carb and fuel lines with new hose and fix hose clips to the each fuel line ends . so now i'm damn sure there is no leaks .but the original lines are black and i replace all them with clear hose so now when engine start i notice there are air bubbles in fuel line after it pass the air filter.

so i remove the direct line to the fuel pump and connect it to the another fuel supply avoiding the filter. (just to a petrol in a bottle without filter) even though i can see the fuel pump inline suck the fuel with bubbles and it pass to the carb also with air bubbles and the return line to the tank also goes with air bubbles.

here i have attach simple diagram to better idea . red marked lines having air bubbles.

So what this mean ? is it normal ? can air bubbles in the fuel line ? is it common ? or fuel pump is faulty ?

also if the pump is faulty is it possible to replace this with electronic air pump or need to find the original pump ?

Edited December 30, 2013 by mensoft

mensoft · December 30, 2013

On 12/28/2013 at 9:07 AM, EAP said:

Hi Mensoft

Please refer to Ebay item number 130889093805. I believe its NEW and the same Pump you are looking for? and selling price is £23. Got a friend who is in the UK and I wouldn't mind asking him to help you to send it to SL.

Let me know

EAP .

thanks for the help. if the pump is faulty im just thinking is it possible to relapse simply with an electronic fuel pump.

if it's not possible ill have a look at the local market also and give u an update .

MasterDon · December 30, 2013

Those mechanical pumps are very reliable and I see no point in converting to an electric unit.

Once again Ï think you should get a mechanic's opinion.Find out for sure why you car is misfiring.These half assed self diagnosis stuff seldom work.

And BTW those clear type hoses are an accident waiting to happen,even the braided ones...Replace with purpose made fuel lines immediately.

Edited December 30, 2013 by MasterDon

MV-5 · December 30, 2013

@mensoft,

How did you make sure that the misfire is not related to ignition path(wires , plugs etc....)?

mensoft · December 30, 2013

On 12/30/2013 at 2:27 PM, MasterDon said:
Those mechanical pumps are very reliable and I see no point in converting to an electric unit.
Once again Ï think you should get a mechanic's opinion.Find out for sure why you car is misfiring.These half assed self diagnosis stuff seldom work.

And BTW those clear type hoses are an accident waiting to happen,even the braided ones...Replace with purpose made fuel lines immediately.

Hi Don,

Thanx for the info. pump is able to suck and take the fuel even intake line is empty . but once it take and push to the carb it goes with bubbles . its not very little much considerable amount of some time big bubbles. i was thinking about electrical pump since this is older model and if its not available to find.

any way ill take the car to machanic but i just want to find out myself b4 go to bass.

is it natural that air bubbles pumps to the carburetor and the return line ?

mensoft · December 30, 2013

On 12/30/2013 at 2:47 PM, MV-5 said:
@mensoft,
How did you make sure that the misfire is not related to ignition path(wires , plugs etc....)?

I Accept most of the time misfire are due to ignition and electrical issues. but i have resonantly changed platinum set ,condenser and park plugs. but wires and distributor are old.

when the car is in flight road or park even if i fully rev the engine there is no misfire. this issue only if i try to climb the hill road. and its not actually misfire its miss like going to stop YES sometimes it stops. so in the same way if i start the car engine is running fine . if i again try to go upwards this happens.

MV-5 · December 30, 2013

On 12/30/2013 at 4:30 PM, mensoft said:
I Accept most of the time misfire are due to ignition and electrical issues. but i have resonantly changed platinum set ,condenser and park plugs. but wires and distributor are old.
when the car is in flight road or park even if i fully rev the engine there is no misfire. this issue only if i try to climb the hill road. and its not actually misfire its miss like going to stop YES sometimes it stops. so in the same way if i start the car engine is running fine . if i again try to go upwards this happens.

Yeah, you are the one who has experienced this misfire. then i hope that you are right. if it is a random ignition misfire, then it will miss few random power strokes. but if it is related to fuel path, then it will miss few(or more) consecutive power strokes.

then based on observations i think that this is not an ignition (electrical) misfire. at least it is not a "RANDOM" ignition misfire.

Edited December 30, 2013 by MV-5

Rumesh88 · December 31, 2013

On 12/30/2013 at 4:21 PM, mensoft said:
is it natural that air bubbles pumps to the carburetor and the return line ?

Initially you may see some air bubbles trapped inside the pipes , pump and the filter coming up as you start the engine. Now th you have a clear pipe for inlet see if there are tiny bubbles appearing on the line as your engine is revved up (if you can bend the clear inlet pipe to form a knee you may see the tiny bubbles gathering to form a big one). If you suspect fuel starvation at the carb then observe the carb reservoir level just after your car stalls while going uphill. It may be slightly below the half-mark because of the inclined position but not more than 2-3 mm below. In fact the reservoir of this type of carbs are positioned facing the front of the car to make sure that more fuel is delivered into the venturi when the car is inclined upward.

BTW did you measure the resistance of your plug wires? If they are of carbon fibre type then you would get readings of approximately between 3k Ohms to 20k Ohms from the shortest wire to the longest.

Davy · December 31, 2013

[Removed part of my answer as Rumesh88's reply just popped up and it had pretty much the same thing I wanted to say about it being normal to have a few small (soda bubble sized) air bubbles in the system as soon as the engine is started.]

If the line to the fuel pump does not have any bubbles, the only explanation that I can think of is a small leak in the diaphram of the pump which is pulling air through the breather line of the pump. You can check if the breather hose is oily or if fuel is leaking out of the breather line immediately after the engine is stopped.

MasterDon is right, mechanical fuel pumps rarely fail and they are much reliable than having a electric pump. The only part which I did not replace on my Lancer A72 after the overhaul was the fuel pump. I bought a replacement but returned it because the original had good pressure although it had been pumping for over 30 years. I too suggest you do the same if yours is faulty.

Now that you have clear pipes, you can easily check if there is a problem with the fuel system by taking the car to an incline and checking if everything works as it does on flat ground.

mensoft · January 7, 2014

Hi All AL Experts .

Simply I would like to say now my carburetor is F _ _ _ EDUP.

The issue was no due to fuel pump. it was not enough petrol goes to engine. to fix the issue had to change the float level in carburetor.

but now i have serious issue. now when i accelerate hell of black some comes out from the silencer. for the all past ages i never had a this kind of a issue and my carb was properly tuned. now all of this thing finished.

I don't mind spending again for a carb repair kit. but i don't want to MAKABAS to touch my carb again.

what this issue can be and how to fix it ?

Rumesh88 · January 7, 2014

Ooops! That's too bad. Where does the float level stand now? Half-mark or well above half-mark? Did you use the same gasket or used a new one? After changing the float level did this baas change idle position and mixture? Whatever it is now your car must be now flying on hills......If so the makabaas has solved your problem after all. (creating another is a different story).

mensoft · January 7, 2014

On 1/7/2014 at 4:16 AM, Rumesh88 said:
Ooops! That's too bad. Where does the float level stand now? Half-mark or well above half-mark? Did you use the same gasket or used a new one? After changing the float level did this baas change idle position and mixture? Whatever it is now your car must be now flying on hills......If so the makabaas has solved your problem after all. (creating another is a different story).

LOL. wt a fly ? it just like Smoke generator. i dint feel to ride it or even to start. looks like pouring petrol.

yes . adjust the mixture that and this all. see this sample picture . (not exactly my one just got from web)

in the middle of the float bowl there is one with sprin

(how this call jet or needle ?) now the fuel level is above that. i think its more than 1/2 .and i brought a new repair kit so all the parts are new. only additional to this is where carburetor fit to the engine with 4 nuts there was a gasket but cannot be used. that newly made with gasket paper. i don't t cause an issue .

Generally what is the correct level have to be ? i would like to give a DIY try Since as i see there is no such a thing just few peaces to fix properly. coz i feel its any way F$*% . so if my DIY not success ill go for a expert.

Finally is this calculator available to buy as new unit ? how much will it cost ?

Edited January 7, 2014 by mensoft

Rumesh88 · January 7, 2014

Admire your DIY spirit. After all it is not a rocket science. I will do my best to see you through the ordeal!!

The float level should be at the middle of the float chamber window. Above the half-mark the mixture will be a bit richer and below a bit leaner. When you remove the top part (air horn) of the carb make sure that the surface is flat (what you can do is to take a small piece of clear flat glass and run over the surface to see if there any warped areas.). Also when you fix the top make sure that you tighten them incrementally in a criss-cross pattern and take care not to over tighten. Hope you have the gaskets for primary and secondary venturi tubes. If you are removing them clean the tiny air passage into the fuel delivery tubes (emulsifying tubes) as well. Also see if your power piston (the spring loaded piston that is at the top middle of the float chamber and attached to the air horn) is not jammed up.

Good luck with your DIY!

mensoft · January 8, 2014

On 1/7/2014 at 9:42 AM, Rumesh88 said:
Admire your DIY spirit. After all it is not a rocket science. I will do my best to see you through the ordeal!!
The float level should be at the middle of the float chamber window. Above the half-mark the mixture will be a bit richer and below a bit leaner. When you remove the top part (air horn) of the carb make sure that the surface is flat (what you can do is to take a small piece of clear flat glass and run over the surface to see if there any warped areas.). Also when you fix the top make sure that you tighten them incrementally in a criss-cross pattern and take care not to over tighten. Hope you have the gaskets for primary and secondary venturi tubes. If you are removing them clean the tiny air passage into the fuel delivery tubes (emulsifying tubes) as well. Also see if your power piston (the spring loaded piston that is at the top middle of the float chamber and attached to the air horn) is not jammed up.

Good luck with your DIY!

Hi Rumesh88,

I started my DIY. and i adjust float level now the smoke comes out is fairly less than early.

I hope that will be fine once clean spark plugs. but the time is the very less i have to spend for this so have to wait till weekend to do the rest. also must run and see sometimes might need to change the gasket coz i open the carb again.

next thing (i cant find the exact picture of my carb)

In bottom of the crab as i marked in yellow there is Y shape connector and its connected as per the picture.

Is that close connector has to be close or where should it connect ?

I doubt this vacuum hose connections.

what is the correct way to connect these . sorry for the i couldn't post the exact images .

Edited January 8, 2014 by mensoft

Rumesh88 · January 9, 2014

To begin with I feel that your idle throttle position could be wrong. This is why I asked if you baas had done a tune up of idle and mixture screws. Now that your fuel level is OK check the plugs, plug wires, vacuum lines (and if possible the ignition timing too) are in proper order and that the throttle cable is slack enough for the idle speed screw to home in. Let the engine come up to working temperature and shutdown. Turn the mixture screw clockwise from its current position all the way using the minimum force (hold the screw drive by the shaft to reduce leverage or use a hacksaw blade piece instead) and note the number of turns. Open the mixture screw by three turns and start the engine. See if the idle is smooth and at around 800 rpm. If not turn the idle speed screw to get to the desired speed. Then turn the mixture screw clockwise 1/8 turn each time taking a few second pauses in between until you feel a slow down in revs. Note this position and turn the mixture screw other way until the revs slow down again. Set the screw at the middle of these two limits. Re-adjust the idle speed if necessary. Now if the idle throttle position and mixture is properly set you would see and feel steam coming from the exhaust. Observe the primary venturi from top and at idle you should not see (and hear the slurping sound) any fuel sprayed into it. As you turn the throttle you will begin to see the emulsified fuel droplets. See if the fuel is sprayed in tiny (subjective) droplets. If it comes as large droplets then you have a issue with air bleeding hole of the emulsifying tube. Need to check your secondary channel as well but let's do that later.

As for the vacuum line in the second picture it should be connected to a vacuum port right below it. I am somewhat confused with the first picture and it would be much helpful if you can post a picture of the carb as it is to get a better idea.