[30ONA]

So my little 2L gv is the smallest engined car I've ever had. But I understand it will be down on torque. However my electrical system seems to struggle. At idle operating any of the following drops the revs and the engine gets a little rough. Ac fan, ac or power Windows. My headlights are also dim at idle and spark up when driving. The other thing I've noticed is when shifting down and the box I'd in neutral the revs temporarily drop while shifting, the ac fan slows down as I release the clutch.

So basically unless the engine is doing at least 1000rpm the engine is laboring when using the electronics in the car. Even to the point where yesterday the wipers slightly slowed down when at idle. Not heaps but just noticeable. This was what really make new think there is a problem. I have a new battery, correct size and 600ish cranking amps.

Is this the alternator dying?

[Gwagensteve]

Maybe, a multimeter will tell you very quickly.

Steve.

[30ONA]

Just ran the following checks
12.89v off
14.00v idle Drops to 13.90 with headlights on.
14.18v above idle no headlights
Slight stumble as throttle opens no electrical load
Engine running winds window up or down drops to 13.5 momentarily
New battery
New o2 sensor
New coil packs
Timing?
Clutch fan worn out
New pcv valve
Fuel efficiency combined 11L/100
I wonder if all these are related? Weak spark or not timed right causing all of the above electrical symptoms.

[30ONA]

I and I can't check the timing because I can't pot the car in timing mode.

[Gwagensteve]

Seems normal to me.

[30ONA]

Fuel economy seems normal, really? 2L 1200kg has the same fuel economy as my 3.5L 1600kg skyline. How is that?

[Kor3y101]

I suppose the same way that my Mazda MPS (which was highly modified) was more economical than my 1.3L Jimny.

[Gwagensteve]

The problem (if there is one- that's not at all clear) may be that there is a problem with idle speed control. This controls idle speed based on load.

Fuel economy is normal. Fuel economy is a result of how much your car weighs, its aerodynamics, its rolling resistance, and its driveline losses.

Three out of four favour your skyline. It's not mysterious.

[30ONA]

Gwagensteve wrote:

The problem (if there is one- that's not at all clear) may be that there is a problem with idle speed control. This controls idle speed based on load.

Fuel economy is normal. Fuel economy is a result of how much your car weighs, its aerodynamics, its rolling resistance, and its driveline losses.

Three out of four favour your skyline. It's not mysterious.

Ok so you given some information thanks. Now can you tell more more about the idle speed control if you think that could be worth looking at.

Does anyone else experience the same symptoms with there electrical parts. I would think that a stock Suzuki or any stock car should be able to power it's own wipers comfortably at idle.

[Gwagensteve]

No, I'm not familiar with the operation of idle speed control in the j20 EFI and don't have a FSM for that model, but it needs to be checked as part of troubleshooting the problem.

[henno]

I had a J20 GV for many years up until very (very) recently. It was one of the best engine's I've ever had and I experienced none of the issues you are describing.

Your votages seem fine though. As does your fuel consumption.

[30ONA]

Is this normal clutch moving after turning off? It looks like it's binding up. Can I inox the pulley/clutch so long as I don't get it on the belt?

[Gwagensteve]

I wouldn't be concerned overly.

[30ONA]

Should there be a rubber washer on my oil cap?

[fordem]

Doesn't come with one from the factory.

[30ONA]

Was just wondering why I've used 4.5L of oil in 8000ks.no signs of leaks or smoke. I've replaced the pcv about 1000ks ago so here's to hoping that helps. Though the new one looked and seemed to operate just like the old one. I was surprised that it doesn't fully close with the spring.

[fordem]

30ONA wrote:

Was just wondering why I've used 4.5L of oil in 8000ks

If it's not leaking it, it's burning it - and with that level of consumption, I'd say it's going past the rings - wet & dry compression tests might be helpful

As for the PCV valve, with no (or low) vacuum it will be fully open, and as the vacuum increases, it will restrict flow more & more.

[30ONA]

fordem wrote:

30ONA wrote:

Was just wondering why I've used 4.5L of oil in 8000ks

If it's not leaking it, it's burning it - and with that level of consumption, I'd say it's going past the rings - wet & dry compression tests might be helpful

As for the PCV valve, with no (or low) vacuum it will be fully open, and as the vacuum increases, it will restrict flow more & more.

I was going you wouldn't say but you have confirmed my fears.

Regarding the pcv valve the way it looked to me was that as the throttle opened and vacuum increases the valve will open. The valve is closed when the little valve moves toward the valve cover and open when moving towards the inlet. Well that's what it looks like. When not fitted the little piston in the valve is towards the valve cover which looks almost closed. When you blow through it air only goes in the direction towards the inlet manifold.

If It was burning it wouldn't the plugs be all black and fouled up? They are nice and clean with the normal white crust around the thread. The tips are clean.

[30ONA]

fordem wrote:

30ONA wrote:

Was just wondering why I've used 4.5L of oil in 8000ks

If it's not leaking it, it's burning it - and with that level of consumption, I'd say it's going past the rings - wet & dry compression tests might be helpful

As for the PCV valve, with no (or low) vacuum it will be fully open, and as the vacuum increases, it will restrict flow more & more.

PM sent

[fordem]

30ONA wrote:

Regarding the pcv valve the way it looked to me was that as the throttle opened and vacuum increases the valve will open. The valve is closed when the little valve moves toward the valve cover and open when moving towards the inlet. Well that's what it looks like. When not fitted the little piston in the valve is towards the valve cover which looks almost closed. When you blow through it air only goes in the direction towards the inlet manifold.

It might be worth your while to research how positive crankcase ventilation systems are designed to work, and whilst you're about it, also intake vacuum on gasoline engines.

Here's a hint - the PCV valve is not a simple one way valve, when it's open, it also controls the amount of flow, based on the vacuum applied to it - the greater the vacuum, the lower the flow; also, intake manifold vacuum is highest when the throttle plate is closed, restricting air flow, as the throttle is opened, vacuum will decrease.

[30ONA]

fordem wrote:

30ONA wrote:

Regarding the pcv valve the way it looked to me was that as the throttle opened and vacuum increases the valve will open. The valve is closed when the little valve moves toward the valve cover and open when moving towards the inlet. Well that's what it looks like. When not fitted the little piston in the valve is towards the valve cover which looks almost closed. When you blow through it air only goes in the direction towards the inlet manifold.

It might be worth your while to research how positive crankcase ventilation systems are designed to work, and whilst you're about it, also intake vacuum on gasoline engines.

Here's a hint - the PCV valve is not a simple one way valve, when it's open, it also controls the amount of flow, based on the vacuum applied to it - the greater the vacuum, the lower the flow.

Thanks.

[30ONA]

fordem wrote:

30ONA wrote:

Regarding the pcv valve the way it looked to me was that as the throttle opened and vacuum increases the valve will open. The valve is closed when the little valve moves toward the valve cover and open when moving towards the inlet. Well that's what it looks like. When not fitted the little piston in the valve is towards the valve cover which looks almost closed. When you blow through it air only goes in the direction towards the inlet manifold.

It might be worth your while to research how positive crankcase ventilation systems are designed to work, and whilst you're about it, also intake vacuum on gasoline engines.

Here's a hint - the PCV valve is not a simple one way valve, when it's open, it also controls the amount of flow, based on the vacuum applied to it - the greater the vacuum, the lower the flow; also, intake manifold vacuum is highest when the throttle plate is closed, restricting air flow, as the throttle is opened, vacuum will decrease.

Looked at a few pages. All pretty much said the same thing. So I had the vacuum part backward. High vacuum at idle lower under throttle. What I still don't understand is if the car is idling there are lower revs and presumably less blow by as there is no load in the engine. So therefore a lower crank pressure. But your getting more flow rough the pcv system. That sounds backwards. Because under load you'll get more blow by and less flow in the pcv system. What am I missing?

Do you know of any good explanations for pcv. All the ones I found only explain, there is pressure and where it comes from but do not explain the dynamics of how it works when the engine is cycling through acceleration deceleration and idle.

[Gwagensteve]

It's not blow by- the high vacuum in the inlet manifold when the throttle butterfly is closed is pulling air out of the crank case.

[30ONA]

Gwagensteve wrote:

It's not blow by- the high vacuum in the inlet manifold when the throttle butterfly is closed is pulling air out of the crank case.

I get that. I'm talking about if the inlet is sucking air from the crank case, where is the air getting into the crank case. The docs I read say the pressure in the crank case is coming from blow by, which I would think is less at idle?

[Gwagensteve]

Filler cap, dipstick and then if sufficient vacuum is achieved, past stem seals, rings. It's not just during the combustion stroke.

[fordem]

30ONA wrote:

What I still don't understand is if the car is idling there are lower revs and presumably less blow by as there is no load in the engine. So therefore a lower crank pressure. But your getting more flow rough the pcv system. That sounds backwards. Because under load you'll get more blow by and less flow in the pcv system. What am I missing?

As mentioned before the PCV valve controls flow, more vacuum, less flow, less vacuum, more flow - under load there is less vacuum, so more flow in the PCV system. If you're getting more flow through the PCV system at idle the PCV valve is defective.

30ONA wrote:

I get that. I'm talking about if the inlet is sucking air from the crank case, where is the air getting into the crank case. The docs I read say the pressure in the crank case is coming from blow by, which I would think is less at idle?

Where do you get the idea that the intake is "sucking" air from the crankcase, and how does this relate to the PCV system? The purpose of the PCV system is to relieve the crankcase pressure that results from blow by without releasing it into the atmosphere and causing pollution. If your engine is "sucking" air from the crankcase, the PCV valve is defective.

[Gwagensteve]

I thought 30ONA confirmed the PCV was installed incorrectly which would do what I am describing?

[30ONA]

Gwagensteve wrote:

I thought 30ONA confirmed the PCV was installed incorrectly which would do what I am describing?

I installed a new one correctly about 1000ks ago. Not possible to install incorrectly. One side is threaded and one side spiggoted.

[Gwagensteve]

Oh, then my comments aren't valid.

[Gwagensteve]

30ONA wrote:

. So I had the vacuum part backward.

I misinterpreted this comment.