Thread: 93 Hard Dash, Spark Plugs and Fuses

dougal sounds like a maf issue to me, especially at revs. if you disconnect the maf does it behave the same or worse?

also, there is a huge bunch of fusible links wrapped up in a flexy conduit behind the batt under the expansion bottle, i lost rear demister, lighters etc etc and when i was looking for poor/ open circuits to the main dash fuse box feeds i traced the problem to the fusible link conglomerate and found most of them were a solid mass of green corrosion, upon touching them they fell to bits. rewired the whole lot and everything worked again as it should

jc

Thanks Justin, I'll have a look when it cools down outside. We've got a mini-heatwave here to follow the real one in Aussie.

So possibly the ignition circuit is fine and just swamped with fuel from the maf reading wrong?
I have heard expensive stories of the idle air stepper motor. But since it idles well, would this likely be fine?

I think it's a hot-wire type. What's the next step if unplug helps it?

*edit*
I just remembered, the smashed ignition circuitry could explain my dead lighter sockets
*/edit*

Make that 2 votes for the MAF. When my 93 stumbles at load and/or pours black smoke at idle it is usually the MAF plug. I take it off and put it back on again with a good wiggle as it goes on and it generally fixes it- at least for a while any way

Originally Posted by justinc

dougal sounds like a maf issue to me, especially at revs. if you disconnect the maf does it behave the same or worse?

also, there is a huge bunch of fusible links wrapped up in a flexy conduit behind the batt under the expansion bottle, i lost rear demister, lighters etc etc and when i was looking for poor/ open circuits to the main dash fuse box feeds i traced the problem to the fusible link conglomerate and found most of them were a solid mass of green corrosion, upon touching them they fell to bits. rewired the whole lot and everything worked again as it should

jc

I pulled the MAF and no difference. No CEL either, which makes me think the bulb is out.
I now think it's just carboned up plugs from no decent run in a long long time. I was able to get it warm yesterday and it started coming right. Driving it around hopefully is far more fun than manually cleaning plugs.

Picture of the EAS working in this thread: 1993 RRC Air Suspension Heights.

"Rest of world" spec cars do not have an active CE light.

IMHO the first thing to check with overfuelling is the temperature sensor for the ECU, which is the sensor on the front RH top of the inlet manifold near No2 injector. It has an injector plug on it.

It should read 300 Ohms at 88C or thereabouts. Sometimes just dirty contacts.

The car should either stop or get the staggers if you disconnect the MAF as the ECU goes into limp home. It will not reset until the next restart.

Look at the temp sender first as this enriches for cold start, while the MAF adjustment does affect mixture it is not in as great a range as the temp sensor.
Regards Philip A

A reminder to check the vacuum hose from the fuel pressure regulator to the back of the inlet manifold. The hose is often loose and perished and therefore falls off. This results in a rich idle mixture. Also check the vac hose is not swollen by passing fuel from a failed reg to the manifold.

Both problems are quite common, I've replaced a reg on a '93 recently and a vac hose on an '87 yesterday.

Originally Posted by bee utey

A reminder to check the vacuum hose from the fuel pressure regulator to the back of the inlet manifold. The hose is often loose and perished and therefore falls off. This results in a rich idle mixture. Also check the vac hose is not swollen by passing fuel from a failed reg to the manifold.

Both problems are quite common, I've replaced a reg on a '93 recently and a vac hose on an '87 yesterday.

I know the cruise-control vacuum line is perished to bits. So I should really check all of them.
But for now it's running well enough to drive it to the 25km return for the WOF (roadworthy check). It's not going to do any significant miles in my ownership.

Originally Posted by Dougal

I know the cruise-control vacuum line is perished to bits. So I should really check all of them.
But for now it's running well enough to drive it to the 25km return for the WOF (roadworthy check). It's not going to do any significant miles in my ownership.

The regulator vac hose is all of 3 inches long, should take you a minute or less to check. The '87 that came in yesterday absolutely stank of rich idle, would have failed a RWC.

The cruise control vac hose is unrelated as it runs off a vacuum pump under the LH battery tray from memory.