Technical Sensors on FIRE

[s5jst]

Hi,

I am wondering how many of them is there because faults on my Goose are always connected to sensors.

How many "electrical-sensored equipement" is on Bosch Spi or Weber (should be same) FIRE engines (the things that normaly goes to hell)

I run on these:
- stepper motor
- throttle position sensor (opposite side of throttle body)
- fuel solenoid (fuel injection)
- temperature sensor
- ECU & distributor (breakerless)
- lambda

I don't know if there is crankshaft or camshaft sensor however I don't know the difference between them. Both collects rpm's, right? Where are they fitted?

Did I forgot any?

 

[weta]

 

[lewey]

Hi,

I am wondering how many of them is there because faults on my Goose are always connected to sensors.

How many "electrical-sensored equipement" is on Bosch Spi or Weber (should be same) FIRE engines (the things that normaly goes to hell)

I run on these:
- stepper motor
- throttle position sensor (opposite side of throttle body)
- fuel solenoid (fuel injection)
- temperature sensor
- ECU & distributor (breakerless)
- lambda

I don't know if there is crankshaft or camshaft sensor however I don't know the difference between them. Both collects rpm's, right? Where are they fitted?

Did I forgot any?

You've pretty much covered it, assuming stepper is what I would call an idle control valve. Crankshaft position sensors can only inform the ECU when number 1 piston is at TDC. It does not say whether it is on a compression or exhaust stroke, which isn't handy if you need to know which cylinder to inject with fuel. By knowing the crankshaft position however, you can determine this and inject fuel correctly. Either can be used to determine RPM, with the crankshaft providing better resolution since it is spinning twice as fast as the camshaft.

However, since your engine has only a single point injector, knowledge of the position of the camshaft doesn't matter as the fuel will simply be sucked into whichever port creates the vacuum. Therefore just knowing the crankshaft position is enough for timing the injector (twice per rotation of the crankshaft).

 

[s5jst]

Thanks for reply. I just made the list of "might go wrong" things which is helpfull for finding mistakes on engine. Mine still has some kind of flu - high idle, stalling, can't idle, irregular idling, to rich mixture and coughting.

Carb is going down today (if there will be some time) and I'll try with one from Uno heart. I think that throttle position sensor is the one to blaim but I'm not sure.

Vital question: Must idle control valve follow the movement of throttle or must valve wait at "idle" position and gain the control over throttle when throttle is released? Mine don't know whether to follow or wait :bang:

 

[lewey]

From my understanding, the idle control valve only really has a large effect at idle. It will move in and out to attempt to regulate the idle speed. If it is doing this quite a lot, there is likely to be a problem with an input from one of the sensors, or the engine has a highly irregular idle that it is trying to stabilise, rather than it is causing. At least the ICV is working though!

My guess for the problem is the one sensor that we have both forgotten- Manifold Air Pressure. This sits on the bulkhead or attached to a suspension turret (been a while since I have been near a Bosch Panda) and has a tube going to the inlet manifold. This is the main method by which fuel is metered. It has perhaps become partially blocked or a new sensor is required, etc.

I would invite anyone else to comment as remote diagnosis of this kind will only ever be a guess really.

 

[s5jst]

Lewey, thanks for MAP :idea:. I visualy checked it yesterday just to find it and figure out where all pipes are attached (from carb to evapourate can under left wheel arch). More investigation will go on today and tomorrow however I think that a brief visit to local mechanic is better because he can check eevry sensor with comp. What a pity I don't know what the resistances of all sesnsors are

I must check some Uno manuals for data...if any.

 

[lewey]

I would say there is a good chance that the mechanic will not come up with any fault codes from your ECU, unless you have had a persistent ECU (injector symbol) error light. On these old systems, you have to normally disconnect a sensor for it to be flagged as problem. Also, you might want to disconnect the battery to clear any faults before running it around a bit and taking it to them as an old fault code may be stored that is no longer relevant.

You say it is running rich with the bad idle? The more I think about it, the more I think this could also be a leaking inlet, either the seal between the throttle body (carb as you call it) and the manifold or the actual manifold to the engine seal. Because the lambda sensor detects the mixture as constantly weaker than expected due to the leak, the ECU over-enriches the mixture to try to compensate. After a while this can be bad for the cat and the lambda, so best to sort soon.

 

[s5jst]

Lewey as I said...throttle body is going to be replaced with Uno's one and also cleaned. Then I will see if there is any difference between them and between "dirty" and clean TB.

Will come back in few days...I hope with good results