Carb Type Car Stop Suddenly When Accelerating

Iroshw · June 13, 2014

I have a Mitsubishi C62A (ASP Model - year 1991) bought 3 years ago. It has 4G15 Carb Engine. There is a huge problem from yesterday.

When I was driving the car yesterday in the evening, I have noticed that the RPM meter goes (very fast) down after accelerating the and when changing the gear. But this doesn't happen when driving the car in the same Gear (say on the Top or 4th) continuously. But when I'm going slowly and when trying to change the Gear the RPM goes down and stops the car. When I need to start the car I need to accelerate a bit if not it doesn't start.

I have cleaned the Carb yesterday in the evening by using a Carb Cleaner (ABRO). Today in the morning I could drive the car a few KMs without any issue but again the problem occurred.

I was thinking about the Petrol since I did pump from a place near Moratuwa (there is a small Fuel Station at the Moratuwa old road near the bridge and Buddha Statute). I can remember there was a petrol block after pumping petrol from the same fuel station in the last year. At that time I didn't know about the issue and the Mechanical guy said that my Carb got stuck and had to clean.

Day before yesterday in the evening I pump, Petrol from the same station. My concern is whether the issue is with the Fuel. But I did clean the Carb by spraying Carb Cleaner yesterday. Also have noticed that there were some oil (not sure) inside of the Carb (on the thing similar to a Drum - moving when accelerating). Also noticed that Drum stucks when moving from hand. Mean when Accelerating the Drum goes inside of a hole, but not moving back (stuck inside of the hole but not always). Is that the issue?

Any idea about the issue?

Irosh

Edited June 13, 2014 by Iroshw

Rumesh88 · June 13, 2014

You already had this issue discussed http://forum.autolanka.com/topic/15483-tune-4g15-carburetor/

What happened then?

Iroshw · June 13, 2014

On 6/13/2014 at 3:57 AM, Rumesh88 said:
You already had this issue discussed http://forum.autolanka.com/topic/15483-tune-4g15-carburetor/
What happened then?

Rumesh: It was another issue had sometimes back related to Clutch Plates and high fuel usage. But this is a new issue started yesterday. And, I forgot to mention that I have replaced my Deco (distributor) a few months ago. But hope there is no relationship between the Deco and this new issue. I still can start the vehicle by accelerating a bit. Some say the problem is with my cab unit.

Iroshw · June 13, 2014

And, my Air filter is a bit old also the Fuel filter.

mensoft · June 13, 2014

Hi,

if the Mac says carb is block . try DIY.

If im you now i have started removing the carb to peaces peaces .

then use the same abro carb to clean the parts . take the carb gasket to spare parts shop and take carb repair kit. assemble the carbulater with new parts .

start your car and keep to worm tune it bit and feel the difarance .

Rumesh88 · June 13, 2014

On 6/13/2014 at 4:57 AM, Iroshw said:
Rumesh: It was another issue had sometimes back related to Clutch Plates and high fuel usage. But this is a new issue started yesterday. And, I forgot to mention that I have replaced my Deco (distributor) a few months ago. But hope there is no relationship between the Deco and this new issue. I still can start the vehicle by accelerating a bit. Some say the problem is with my cab unit.

This type of carburetor (local term "bothal type") is a bit difficult to clean by spraying from the top because there is a moving part. Some of the gunk dissolved during cleaning may jam the cylinder (In fact it moves on a Teflon coated linear bearing). The best method is taking it apart and cleaning it. Find someone who can do it for you.

Iroshw · June 13, 2014

Yes Rumesh, the Cylinder (inside of the Carb) should move smoothly when accelerating. But now it gets stuck somewhere when accelerating (not always). I tried to clean the cylinder by spraying Carb Cleaner but didn't work. I put my finger into the hole after moving the Cylinder aside, I saw some dirt and also some oil (not sure exactly) inside of the hole. It is really hard to remove them even using the Carb Clean. I really like to get that Drum (Cylinder) out and clean. The problem is I can't remove the screws, I tried all my screwdrivers but didn't work. Any idea? Will I mess the thing?

Iroshw · June 13, 2014

On 6/13/2014 at 8:20 AM, mensoft said:
Hi,
if the Mac says carb is block . try DIY.

If im you now i have started removing the carb to peaces peaces .

then use the same abro carb to clean the parts . take the carb gasket to spare parts shop and take carb repair kit. assemble the carbulater with new parts .

start your car and keep to worm tune it bit and feel the difarance .

Yes, I tried to remove it, but trust me, the screws are like the hell.

Rumesh88 · June 13, 2014

On 6/13/2014 at 3:02 PM, Iroshw said:
Yes, I tried to remove it, but trust me, the screws are like the hell.

It is very difficult to remove these screws with the carb mounted on the engine because you cannot hold a screwdriver and exert a sufficient force on the screw. There are several methods to clean tough gunk but here you may have to take a chance for it may make the matters worse ie if the dissolved dirt ends up further down the piston housing. Still worth giving a try by spraying WD40 or little diesel an leave overnight before finally washing down with carb cleaner. Hope you will find some of the downloadable files useful at http://igunosmech.blogspot.com/2011/12/aisan-variable-venturi-carburetor.html

Edited June 13, 2014 by Rumesh88

mensoft · June 24, 2014

On 6/13/2014 at 3:02 PM, Iroshw said:
Yes, I tried to remove it, but trust me, the screws are like the hell.

if you put a tiny drop of break oil to those screws it will loose otherwise try WD40 . brake oil may be not advisable on carb.

get the advice from Rumesh88 also if you gona try with break oil. and it have to clean the parts very well if you put the break oil.

Iroshw · June 25, 2014

Guys,

The prob is almost solved after cleaning the carb unit by spraying Abro Carb Cleaner. But rarely stops the car when driving. I guess this happened due to bad Petrol. Same thing happened when I pump petrol from the same fuel station sometimes back (near the Buddha Statue and Bridge at Morauwa old road, after the junction).

Irosh