Team-BHP - Carb Gypsy problem : ocassional Drop in engine power during highway driving

Hi all
Over the last 1 month I have been experiencing a peculiar problem with my gypsy which is cropping up unexpectedly without any warning and till date has happened on 4-5 ocassions.

The problem can be best described as sudden drop in engine power at highway cruising speeds usually in 4th or 5th gear. I am cruising at 80kmph and suddenly there will be drop in engine power notwithstanding additional acceleration that I provide by flooring the accelerator. Sometimes the vehicle will give jerks and then there will be a drop in engine power. I am able to recover from this situation sometimes by down shifting and sometimes i need to come to a dead halt, shut off the engine for sometime and then when I restart again the problem disappears.

This problem has never happened when driving in city or in the jungles in any gear. This problem has cropped up suddenly in the last 1 - 1 1/2 months. I may remind you all that this vehicle had been sourced from the army auctions in Pune, Its a 99 carb gypsy king with a brand new mikuni carburettor. It is giving me a constant average of about 15-16 kms to a litre of petrol since i acquired the vehicle.

I do considerable highway driving with the gypsy and this problem that I describe never happened before this. I have driven her for about 15,000 kms after acquisition 6 months back. The longest drive so far was the initial 850 kms pune-nagpur run which was executed flawlessly by the vehicle.

The carburettor was never cleaned/serviced/setting changed in the last 6 months. However I have noticed that the sparkling new carb has been covered with black coloured grime over the last 6 months of usage.

Another incidental thing which I found out yesterday while crawling beneath the vehicle was that the underside of the transfer gear box (I hope thats what it is called) was coated with oil. However I have never yet discovered oil spots below the vehicle. I wil try to take some pics of the underbody and post tomorrow.

Another find was that the engine oil level was low and it required about 1 litre of oil to top it up. I'll check the level again tomorrow and post my findings.

I don't know if these things are related or not. I am just reporting what all I have found.

Please let me know if anyone has experienced something similar and what may be the possible solution for this. I can very well get the carb cleaned up but my logic is if it is carb problem, then why is it not getting replicated incity. And why is it cropping up sporadically. Gypsy experts please help me.

regards,
Dr. Abheek Ghosh

Hi Abheek,

Though I'm not a gypsy expert, I would suggest you;

Check the following

1) Carburetter (Flooding/Linkages/Overflow/Butterfly Vanes)
i) Air-Filter Assy. open and clean, check for leaks/holes
ii) Fuel Delivery System
iii) Fuel Tank for rust/sediments
iv) The grime on the carb can be from regular running and if the carb floods, then gummy petrol smelling deposit.
v) Also Check the Distributor Advance/Retard.
vi) If there is grime inside the carb, then the air-filter has a leak.

2) For the transfer-case
2A) Check if the oil on the T-Case is gear-oil (sulphur smell) or black/brown Engine Oil.

2B)If it is Engine Oil then you may have a problem with your
i) Crank Case

ii) PCV Valve - Postive Crankcase Ventilation Valve

iii) Main Bearing Seals, this is the worst case, indicated by the clutch becoming slippery i.e engine oil on the clutch pate & Assy.

2A ii) Check and clean the Breather Plugs. If the Plugs are blocked, then while running, the oil heats up and the hot air/gasses cannot escape, thereby creating a High Pressure inside the T-Case and vent through the oil-seals or weaker joints (sealing).

iii) After Cleaning the Breather if there is Gear Oil on the T-Case after running, service the T-Case.

In Longer distance runs the Engine/Gear Box/T-Case Differentials heat up much more due to continuous running and higher speeds.

Regards,

Arka

Quote:

Originally Posted by ex670c (Post 1652712)

sir, I am really overwhelmed by the amount of information you posted in a single reply. To get all the things checked on your list, I will take the gypsy tomorrow to my mechanic and will then post the findings. Thanks for taking your time out and replying.

Quote:

Originally Posted by MexXxentric (Post 1653040)

Was it raining in the recent days?
or did you try a new fuel station?

Most likely it will be some particle clogging the jets in carb.
Or even water in the fuel system.

You didn't mention anywhere that your engine is over heating.
that also have the same symptom, but followed by "ssshhhhhhh" from radiator hose:D

The carburettor was never cleaned/serviced/setting changed in the last 6 months. However I have noticed that the sparkling new carb has been covered with black coloured grime over the last 6 months of usage.

Inside or outside?

No Sreejith.
No rains here in Nagpur.
I have been using only Extra premium petrol in the vehicle only from reputed sellers.
There is no symptom of engine over heating. No noise as u describe in your post.

Thanks again.

I wonder if anyone has had this issue ever with their mikuni carbed gypsy king.

regards,
Dr. Abheek Ghosh

Quote:

Originally Posted by abheekg (Post 1653308)

Hello sir
I saw your reply just after posting the previous reply.
Please pardon my ignorance as I don't know what an external electronic fuel pump is. All I can say is that the fuel pump on my gypsy was never changed after my acquisition. Do you think that the fuel pump could be an issue ?

regards,
Dr. Abheek Ghosh

Abheek,
From what you describe, it seems to be a either a fuel supply issue or an electrical fault. Get the fuel pump checked. In the 1.3 carbureted Gypsy, the fuel pump is a mechanical unit running off the camshaft. Since it is a relatively expensive replacement, it is usually replaced with a cheaper in line electronic unit when the original goes bad.
While you are at it also check the fuel filter and get the carburetor serviced. Check the battery for loose terminals and the ignition coil for overheating.

Also, do not ignore the leakage. If you are losing oil and the bell housing area is covered with oil, most likely you have a blown main rear seal. Get it replaced before it contaminates and kills your clutch as well.

Vaibhav

Hi Abheek,

I believe i exactly know what issue you are facing. I had a similar issue since i am running the same setup on my jeep .. 99 carb King engine with king gearbox. I have tried a lot of things to overcome this. I have replaced the King carb to a esteem carb, Have headers with FFE , Universal air cleaner and a electronic fuel pump. Have checked for clutch plate and pressure plates. It has improved a lot. However recently i did some 700 Km run it did this strectch without any issues. the only time i felt some sluggishness stopped the vehicle and had a cup of tea and we both were all set. I would suggest go for electronic/electric fuel pump that should solve the issue. Thats just my guess.

Quote:

Originally Posted by Pardus (Post 1653707)

Dear Abheek,

I have faced similar problem and had thought that the problem was with flow of fuel. But on close inspection realised that it was with alternator/dynamo. Check the alternator and other electric wiring as well, this could happen if there is no continous flow of power to engine. could be a loose wiring or issue with alternator.

Quote:

Originally Posted by gotzuk (Post 1653716)

Hello Pardus and Vaibhav
Thanks for your inputs.
The gypsy is going to the garage to get all of these things checked out. Based on the replies from all of you I will be checking on the following for the drop in power issue :
1] carb assy complete check up and servicing if needed [its a 6 month old brand new unit for God's sake !! :Shockked: ]
2] Air filter assembly complete check up
3] Fuel delivery system including fuel tank, pump, filter - complete check up
4] Electricals - alternator/ignition coil , carb and alternator wiring

I am also taking the oil leakage issue of the transfer case very seriously. I will check and replace all that will be necessary.

Given my background as a medical practitioner who always thinks before ordering any expensive diagnostic tests , I am finding the current process of diagnosis of the problem of my engine power loss by elimination a little odd but I guess I will have to get used to this thing.

I wonder if there are standard protocols and flowcharts that some novice like me can refer to with regards to the various components of a vehicle for the process of troubleshooting.

Till the time I get experienced and am able to diagnose any issue of my vehicle on my own, I will be needing the help of all the experts.
Hats off to all the guys who have tried to give me pointers and are helping me out with this issue.

regards,
Dr. Abheek Ghosh

Quote:

Originally Posted by abheekg (Post 1655831)

Given my background as a medical practitioner who always thinks before ordering any expensive diagnostic tests , I am finding the current process of diagnosis of the problem of my engine power loss by elimination a little odd but I guess I will have to get used to this thing.

I wonder if there are standard protocols and flowcharts that some novice like me can refer to with regards to the various components of a vehicle for the process of troubleshooting.

Hi Abheek,

Some of us prefer to check the cheapest (lower billing) solutions first and move onto expensive solutions. That is the BASIC flowchart.

But it does not mean, we just treat the symptoms :D.

Regards,

Arka

Hi Arka (and all the others who have replied)

The gypsy is at the mechanic's workshop getting checked up.
Mechanic could not diagnose the drop in engine issue yet and is working on it. So am I.
I am doing what I do in my practice. When I am faced with something that's new, I to read up and look into references for similar problems with the others which have been already documented. I'm doing the same here. lets see where my research leads me to.

In the meanwhile mechanic reckons that the oil leakage issue is grave.
He's found oil in the cam, tappet, thinks that the main oil seal is gone. and so are a few other oil seals (i don't exactly remember which oil seals he mentioned) .

In the hindsight, I feel that the gear changing has become a little stiff in the last 15 days also (does it indicate oil in clutch issue ?)

He also says that engine is probably giving back compression (dunno what that means) and when I asked him about what was the best solution for this - he said that he will open the engine and most probably the piston rings will have to be changed. I asked him whether a complete engine work needs to be done and he said that it doesn't look necessary at this stage. but he said that he will check and tell me by tomorrow.

What do you guys think I should do. i am in a mood to get the complete engine overhauled, but mech says that complete overhaul may not be necessary. what do you have to say ?
What does a complete engine overhaul of the gypsy involve ? and if i have to think of a full engine overhaul what settings can I think of for the overhauled engine (i get the impression that some improvement in engine power/performance is possible during the overhaul process) and how do i ensure that the overhaul is done to the factory standards (since this is being done by my trusty local mech) ?

Lot of questions that I need help on.

And when the engine bay is being opened, what other things do i need to check / look into / replace for the future ?

regards,
Dr. Abheek Ghosh

Quote:

Originally Posted by abheekg (Post 1663541)

He also says that engine is probably giving back compression (dunno what that means) and when I asked him about what was the best solution for this - he said that he will open the engine and most probably the piston rings will have to be changed. I asked him whether a complete engine work needs to be done and he said that it doesn't look necessary at this stage. but he said that he will check and tell me by tomorrow.

Engine is a sealed block, its supposed not to leak any gases during compression, but in case of old and damaged engines the ring surface is uneven and cannot hold the pressure inside the chember and lets the gases to leak through(usually) inlet spots. This means engine oil getting burned along with air + fuel mixture. This can be noticed by placing your palm over the dipstick valve when the engine is running. You can feel gases hitting your palm. In case of new engines this dosent happen.

Quote:

Originally Posted by abheekg (Post 1663541)

What do you guys think I should do. i am in a mood to get the complete engine overhauled, but mech says that complete overhaul may not be necessary. what do you have to say ?

Great idea but its better to get a engine compression test done first, a complete engine overhaul involves replacing piston rings, reboring cylinder walls, replacing pistons, replacing main and connecting rod bearings, and restoring the valves. Also overhauling parts like the starter, distributor, carburetor and alternator while the engine is being overhauled is common to ensure that the entire runs like new. An important point to note is this engine has to be run in like a new engine.

Quote:

Originally Posted by abheekg (Post 1663541)

What does a complete engine overhaul of the gypsy involve ? and if i have to think of a full engine overhaul what settings can I think of for the overhauled engine (i get the impression that some improvement in engine power/performance is possible during the overhaul process) and how do i ensure that the overhaul is done to the factory standards (since this is being done by my trusty local mech) ?

The process is somewhat same to what i have mentioned above, but the answer to your question depends upon how knowledgable your trusted mech is. At maruti an engine over haul costs 30-40K, but there are a lot of people who can do the job better than maruti at 1/3 that cost.

Quote:

Originally Posted by abheekg (Post 1663541)

Lot of questions that I need help on.

And when the engine bay is being opened, what other things do i need to check / look into / replace for the future ?

regards,
Dr. Abheek Ghosh

After a complete engine overhaul the car is as good as new, so it just has to gothrough the regular precautions one takes in a brand new car.

Pramod