1994 Cavalier LSi C20NE (was C18NZ) Work-horse

[Robsey]

aww wat a total shiter. another set of shells may be needed

It was perfectly fine, until I put fresh oil in yesterday

The engine has only done 75K miles so unlikely to be worn...

must be the Digi Dash at fault it will be about 20-odd years old... what a right royal pain in the arse

I just ain't stripping another engine - I have decided that I will simply run the car until it refuses to run any more.

[Envoy CDX]

Cack but suspect for the same issue to crop up on 2 cars.
As you say it could well be electricals.

[btcctroy]

aww wat a total shiter. another set of shells may be needed

It was perfectly fine, until I put fresh oil in yesterday

The engine has only done 75K miles so unlikely to be worn...

must be the Digi Dash at fault it will be about 20-odd years old... what a right royal pain in the arse

I just ain't stripping another engine - I have decided that I will simply run the car until it refuses to run any more.

ah yes i read it wrong most prob and electrical fault as stated.

sounds most likely.

[planetc]

My money was on the sender, still is. I am sorry to hear that you have had all that effort for nothing rob. Look on the bright side, the 1800 was ready to be changed anyway so not really wasted effort.

[Envoy CDX]

Look on the bright side, the 1800 was ready to be changed anyway so not really wasted effort.

Just think of the 115 pony grin factor.

[snowy]

I doubt it would be the dash at fault, more likely the sender or wiring to the sender.

[Robsey]

I doubt it would be the dash at fault, more likely the sender or wiring to the sender.

I have changed the sender, but it made hardly any difference (brand new item).

I would think that it coud well be the dash... assuming that part of the componentry is getting hot due to breaking down or a faulty solder joint...

I could well try running two new wires to the clocks...

The oil light flashes just as my pressure gauge value drops below 0.3 bar. (all the bars go out)

Suppose I could try one of my single connector pressure switches. - just to verify the oil light switch accuracey.

Got a replacement dash on it's way soon... so can swap the gubbins over..

and I'll look at getting another sender at the end of the month - (payday).

The senders are dearer than a replacement dash and transducer

[planetc]

As I said before, there were a lot of these senders around that did this even from new, or nearly new. It's possible that the replacement was one of the bad ones.

[btcctroy]

i cant unerstand how a dash light would show the wrong pressure.

the dash light is operated by a pressure switch that is on or off.

get a garage to test the pressure. it should be around 2 bar at idle. 75 psi at 5000 rpm with engine warm.

this will then tell you the problem

[planetc]

2bar at idle sounds a bit optimistic?

[btcctroy]

ok i was bit off. the oil pressure shouldnt be less than 1.5 bar at idle.

the light comes on at .5 bar if i remember.

Rob how long has this engine not been used for, before you ran it

[planetc]

Yes, 7psi if I remember correctly.

[planetc]

I think if it were me I'd just drive it, as long as there is good pressure when you are at speed it's not likely to be an issue, if it's knackered then you have nothing to lose. If it really bothers you plug in and raise the idle a bit, you said it's a bit slow anyway?

[Robsey]

I think if it were me I'd just drive it, as long as there is good pressure when you are at speed it's not likely to be an issue, if it's knackered then you have nothing to lose. If it really bothers you plug in and raise the idle a bit, you said it's a bit slow anyway?

I know where you are coming from with this, and I know that I am just becoming a bit of a big girly with a frilly petti-coat on.

Just to me - lights mean trouble - ha ha

So, what do you mean by "plug in and raise the idle"?
are you talking Tech 1 or something?

I have Op-Com, but it is next to useless for anything before 1996
and we are talking a 1993 engine -

as said, dash is on its way, so will swap that, then the sender later...

And thanks to Envoy CDX, I also have a spare ICV

[planetc]

There was an option within tech1 to adjust the idle speed, within a certain range. 90% certain this was available on the C20NE, remember playing with them when people used to complain of the car vibrating on idle. We used to tune it out with the idle speed. If you could raise it a little bit then it might be enough, you said it's a little low anyway?

[Robsey]

Yup - will look to see if op-com can do this, as it appears to be supported on Astra-E and Calibra

I fitted my other Idle Control Valve, and the vibration / wobble appears a little better.

Otherwise, I will just tweak up the revs by a bit as soon as i put an analogue tacho gauge on the car - I will then be able to confirm how accurate my digital scale is.

No light oil light on the dash this morning
And bizarrely my MPG was very good today... although I did drive like an old fart to save fuel..

33 mpg around town, 46 mpg cruising sedately on the motorway

[planetc]

[Robsey]

Turned up the revs, (without my analogue tacho / dwell meter).

Increased the revs by adjusting the stop screw on the throttle body cam..
Just fast enough to ensure that the oil light does not come on, but slow enough for the 1000 rpm marker not to illuminate.

Still a minor wobble / vibration, but I can cope with that.

[planetc]

Turned up the revs, (without my analogue tacho / dwell meter).

Increased the revs by adjusting the stop screw on the throttle body cam..
Just fast enough to ensure that the oil light does not come on, but slow enough for the 1000 rpm marker not to illuminate.

Still a minor wobble / vibration, but I can cope with that.

Make sure it still recognises idle on the throttle pot if doing it this way, or you'll lose your overrun fuel cutoff.

[Robsey]

Ah - didn't think about that

not sure of any other way to adjust the idle... couldn't find anything on TIS

must agree, I didn't see my fuel computer go to 999.9 on the instantanious consumption when driving down the hill to the supermarket - ... oh bugger

I tried adjusting it with the circlip on the main cable, but I couldn't get a suitable rev
Either too low, or revving it's tonkers off.

I'll have another tinker tomorrow during my lunch break... I'll take my lap top this time.
Revert the cam stop to its original position, and then see if I can program the ICV and TPS to suit.

[btcctroy]

ah so u dont actually have an oil pressure light that comes on. perhaps something is amiss

[Robsey]

ah so u dont actually have an oil pressure light that comes on. perhaps something is amiss

The oil pressure light has gone off in the picture, as it was taken after the adjustment to throttle speed was made...

as said in an earlier post - high enough revs tobuild up sufficient oil pressure to put out the light, but low enough, not to illuminate the 1000 rpm marker...each little marker stands for approx 200 revs... so 4 little blocks are illuminated. Oil pressure is the top indication on the left side.

Warnings and Gauges are
1) Oil Pressure switch followed by pressure gauge
2) Battery light followed by the volt meter
3) Temperature warning light followed by the temperature gauge
4) Fuel warning light followed by fuel gauge.

[Robsey]

Digi Dash Explanation...

[Robsey]

Make sure it still recognises idle on the throttle pot if doing it this way, or you'll lose your overrun fuel cutoff.

Checked it today, and I got the tell-tale 999.9 mpg on over-run (cut-off)

So yes it recognises idle etc

[Robsey]

Checked the tacho against my old halfords Equus analogue gauge.

Reading aprox 650 rpm

Well that may well be a good reason for the lack of oil circulation pressure.

Now then, where can I find a nice man with a Tech 1 unit?
...to turn up the revs to 800 to 850 rpm.
Could do my fuel computer whilst they are at it - ha ha

New Digi dash arrived too - woo hoo. will take a look at it when I get home later.