Engine struggles to start on sideways incline

[Ryperd]

I had a strange engine issue this weekend on a road trip. I pulled over on the side of the road and switched off the engine with a substantial but nowhere near alarming incline to the left (roll angle?). Basically, the right tyres were on the tar and the left were in a drainage line. After about 15 minutes I tried to start the engine, but the starter just turned like there was no resistance at all. Eventually it sputtered to a start, and then the engine ran fine, even on the incline. A bit later I stopped again on a bit less of an incline, and again it struggled to start.

I haven't noticed an issue like this before - would it be some issue with the carb? It's a 4Y engine with original carb (I assume it's Nikki or the other common one). The carb was overhauled not so long ago, but I'm not sure it was done very well.

[Mud Dog]

It's not that likely to be a carb problem if it's an original Nikki or Aisin, unless they changed something with the 'overhaul'. Those carbs were designed to work with more severe pitch and yaw angles than the average run of the mill units. Check that the float level is in the middle of the sight-glass on the float chamber when the vehicle stands level - it might have been set too high or too low.

It may also be time to do a compression test and check the ignition system (coil, leads, plugs, condenser).

[Jacques T]

Sounds like the fuel line runs dry.

[LouisZ]

Check the float window on the carb's window. It should be half, if it is above the half mark you over fuel, if you see the line is under half you get fuel starvation.

Also, how much fuel was in the tank?

[Ryperd]

The fuel sits below half when the engine is off; once I start it comes up to half. It does look a bit damp on the one side of the carb so it might be leaking a bit somewhere. I can't find a label on the carb, and I can't remember actually seeing one when I had it overhauled. There are some serial numbers on the front under the float window but there was no manufacturer logo. I'm not the most observant guy in the world so I might have just missed it. I have my suspicions about whether the carb overhaul was properly done or not.

The tank was more than half full when it struggled to start. There are two tanks, and it could have been some strange air lock issue because of the angle I guess, but the fuel gauge was definitely not empty so it's not likely that all the fuel was sitting in the extra tank.

I know that the timing is out (backfires very occasionally, especially at the bottom of a downhill when you put your foot back on the accelerator, and pushes out some black smoke when I start the engine), but would that affect starting on an incline? The engine is new (GWM 4Y import, about 7,000km on the clock) and it's definitely not using any oil. Engine generally seems to run well (if a bit thirsty) so I doubt that it's a compression issue? Choke could have an influence on the smoky start, but it shouldn't cause any problems starting on an angle ?

I'm going to get the timing set tomorrow morning so I'll see if that improves the smoke on startup. Once that's done I'll test it again starting on an angle and see if the problem still persists.

Come to think of it, I'm pretty sure this will only be solved with an EFI conversion!

[Ryperd]

Timing was set to around 7/8 which seems to be the recommended setting, so I don't think that would be the cause of the black smoke on ignition. Must be over-fueling by the carb?

[Mud Dog]

Tend to agree with that. Black smoke indicates over-fuelling ... could be that it flooded a bit, but that's also not normal. If the float level is correct then I think there's something else amiss with the carb.

[Ryperd]

Also very sluggish on pull-away (like there's an accelerator lag or something) and not as economical as I would expect (6-6.5km/l driving economically), so the carb is on trial for various crimes against performance. So now the question is whether to try a different carb specialist or bite the bullet and see if Louis has a gap somewhere in his calendar to work his magic on the engine.

[zepplin]

Bite the bullet.....Louis knows his stuff.

I'm sure a gap in his calendar can be obtained with a bottle of the cape's finest............

[Mud Dog]

Rather than spend money on a new carb, I would try go the EFI route if you can't get your carb sorted. It's unlikely that you will get your outlay back in fuel savings, but you'll have better performance and some peace of mind.

[Ryperd]

Rather than spend money on a new carb, I would try go the EFI route if you can't get your carb sorted. It's unlikely that you will get your outlay back in fuel savings, but you'll have better performance and some peace of mind.

I've been wanting to get the EFI done for a while, so I guess this just helps make the decision! Even if I get an extra 250m per litre, it should pay itself off in the next 500,000 km I plan on doing, Andy .

Bite the bullet.....Louis knows his stuff.

I'm sure a gap in his calendar can be obtained with a bottle of the cape's finest............

Louis has helped me out in a serious pinch before... I think I owe him at least a case already!

[Ryperd]

Just a question on the EFI. I know that there is always a compromise between economy and performance, but can you have two maps and switch between the two? Or is it not just the software but the overall tuning that must be in set?

[LouisZ]

Hi Rudi,

You can set a map for power, then you can set it for economy. 2 different maps all together. For example about a few months ago I tested it, power std, no cams no nothing just the Efi, on the rear wheels was 97hp, for a short while we got over 100hp but we saw the heat gauge went up. We moved back to about 90hp, I drove it for a day, well fuel economy was out of the door.

What we now do is to set it to about 75 to 80 hp on the wheels, this gives a good economy of about 7.5 to 8.5km/liter, depends on average speed, how you drive the SFA and then too the weight of extras on the SFA.

So it is 80% software mapping and a bit of timing set that get you from the power settings.

Efi is there to make the ride smoother, gives more power and if you get used to the power then you start saving fuel.

[Mud Dog]

It is possible to have two maps, depending on the ICU, whether it has that facility or not. Then you can toggle between the maps for your requirements at that time.

[LouisZ]

Most of the Ecu's you find these days its either or. Now talking about the more affortable ones. Yes the expensive ones can, but then you have to pay about R5k to R25k just for the ecu, not worth it.

I know a while back Mr. Turbo had a pod thing you install inside you set your mixture, were more or less. This is not effective because what about the right timing that goes hand in hand with it?

Then the OE ecu comes into play, its optimum solution, yet then more sensors, more costs. And also majority of the importers don't even look of getting the OE Ecu with the 3YEF or 4YEF motors, that's not their market. I ran across 1 OE Ecu sofar in the 5 years I been doing this. it take a lot of research to even get close to a reliable electrical diagram to understand it, then too 3 times a year or so the diagram changes, the ecu pinouts change too.

[Ryperd]

If you have to install more sensors then that's another possible point of failure. For me, 4Y engines should always be reliable before they are powerful or economical...