Car won't start - Electrical Fault - No spark or Fuel

[Paul240480]

Good news. The relays do have a life expectancy of about 12-15 yrs. The joints dry out & sometimes gives an intermittant fault first before faling completely.

Thanks for teh update, glad you're sorted.

[veegard]

Hello,

I think I have almost the same problem as you...

Car's been driving perfect, except for a very high fuel consumption. But it never stops, always starts - even if it's quite cold outside (live in Norway).

So, one day I was changing the stereo, parked it outside, it rained a bit, and my hood was open.. Don't think that should matter though!
After some hours, I was done, tried to crank it, didn't start. Assumed I had flattened the battery, I charged it until the morning after.
I crank it, starter turns, but nothing more happens.

I check if there's a spark, no spark.
I check if there's a spark in the plug cap, no spark.
I check if there's voltage to the coil. All connections read 0v.

I check the crank sensor (the one at the right side of the engine, way down there...).
I listen for the fuel pump running. No fuel pump.
I try to diagnose the car, but I only get a response from slot #7 (which is ABS or airbag or something)
Socket #2 only gives me a faded weak LED, which gets stronger when I push the button. But no response.
The two other sockets that there's something in gives no reaction other than the light lighting up as long as I hold down the button.
Socket #7 gives me code 1-1-1. No errors.

I shuffle the relays about a bit, the ones that are acccessible from the engine bay.
No change or effect.
I read this thread, read about the fuel pump relays. I try looking for them at the driver side, only to realize that they're at the right hand side, which isn't the driver side here.
I find two relays that look similar to the ones described here. I take them off, one for one and check them.

I ohm the two connected poles. 85 and 86, was it? I get 75 ohm.
When I feed the relay with +12v, the relay clicks. I assume it's working, put it back in. I check the next one, same reults, also appears to be working fine.

When i check voltage in the socket I get exactly the same results as forementioned in the post.
I switch them around in their sockets, to see if that has any effect. Still no go.

I unplug the ECU of the car (the humongous SCART-contact). It suprises me that I cannot see any difference in the behaviour of the car whether I have it plugged or unplugged. The same warning lights flash, the SRS light goes away when it should, oil pressure goes away when it should. As it is now, I don't know if I have a dead ECU, or if the ECU has no power or something.

Which leads am I supposed to check that gives power to the ECU (or other important needed cables)?


The dashboard illuminates, the oil-light lights up, and disappears a second or so when I start to crank the engine.
The stereo works fine
Lights, turning signals, heater, everything works as it should when it's off.
When I crank it, everything dims as it should, and the starter sounds very normal.
Never had any problems the one month I have owned the car.
The car has previously had installed a DEFA 800-series alarm, but I think all of it except an unplugged siren and a glass-breaker microphone is left.. I can't find any immobilizer atleast.

Known problems with the car is that it has excessive fuel consumptions (1.4l per 10km, that's like 25mpg-ish, and it's with nice driving too!)
Thermostat probably broken, not showing engine temperature.

The car has gas, oil, coolant and plenty of power on the battery.

Help!

[jlgrosvenor]

Sounds like you car may have a few problems.

What engine do you have, B18U like mine? I am getting 35mpg around town, and 50mpg on very long motorway runs. Typical average consumption is about 450 miles from about 50 - 52 litres of fuel at fill up. For this issue, I would guess that it might be oxygen sensor in the exhaust, or the engine temperature sensor on the front of the head. Both can be checked for appropriate resistances with Haynes manual instructions.

Just a note, the temperature you see on the dashboard does not relate to the two sensors I have just mentioned. There is a separate sensor for the dash temp indicator, and this is on the back of the head on the left-hand side of the car.

As for the car not starting, have you checked the resistance of the windings in the ignition coil pack? I think it is mentioned in this thread.

Good luck.

[veegard]

I have a B20U.

I do think that for a fact, the engine is running very hot. I've noticed how water evaporates very quickly when I drive through puddles, and how the metal "ticks" when I turn it off. I think the engine is oversaturated with gas, but I'm gonna take that problem when I get the car running again..

I haven't, no. But I think I have the bogus connection in reach!

The pin 87 on the fuel injection relay (i have one black socket relay and one white socket relay) is split up into two different leads. One obviously going back to the ECU, and one going.. to somewhere behind my stereo, where it just hangs loose. It's a red and thick-ish wire (looks like it supplies power opposed to being a signal cable).
I have to figure out where it's supposed to be connected, then maybe I get lucky and get to start this thing again!

[jlgrosvenor]

A fast water evapouration and 'ticking' are not necessarily signs of an overly hot engine. If I were you I would be making absolutely sure the resistances on the TWO temperature sensors are correct. I would also be checking for continuity down the wires to the dash and ECU. If you look at the relevant Haynes manual wiring diagram, it will tell you which pins the engine temp sensor should be connected to. If you measure the resistance of the temp sensor, and then measure the resistance across the appropriate ECU scart lead wires, you should get the same resistance reading. I did this for almost all sensors on the engine whilst trying to find a fault.

You can do the same thing for the engine temp readout (dashboard) sensor. This does not connect to the ECU lead, but should be accessibly on the back of the dash (just about anyway).

I am sure you know, but running the car too hot will dramatically reduce it's life, but on the otherhand, I would expect better economy. As far as I can remember, the higher the difference between the air coming in, and the air going out, the more efficient the engine - hence racing cars using higher temperatures and jet turbines seeking better and better materials to push up operating temperatures for efficieny gains.

[veegard]

I'm going to try all that later, right now my main pri. is getting the thing started again.. Which has proven to be difficult.

As you can see in my thread here (http://www.volvo-forums.com/t24624-4...starting33.htm), I have a loose wire on the black-socketed relay at the right hand side in the car.
It's red, kinda thick, and goes nowhere. And I saw the same wire while swapping my stereo, maybe I've unplugged it while pulling cables.
And it doesn't seem to be placed very logically at all, I don't really know.. what it does.

[veegard]

Okay, done some more testing now.

Seems like the red wire I was talking about is an aftermarked one, and doesn't belong there.. If it touching anything could have ducked anything up, I don't know!

I have the Fenix 3B aswell, and I don't know where to measure and which values to expect.
I do however get +12v on a couple of the ECU plug connectors.
I could ohm my crank sensor fine from the ECU plug, 218 ohm.
Relays are apparantly working, but will test them again..

[gamel]

The vehicle owner who does his or her own maintenance according to the recommended service schedules should not have to visit and use this section. Modern component reliability is such that, provided those items subject to wear or deterioration are inspected or renewed at the specified intervals, sudden failure is comparatively rare. Faults do not usually just happen as a result of sudden failure, but develop over a period of time. Major mechanical failures in particular are usually preceded by characteristic symptoms over hundreds or even thousands of miles. Those components which do occasionally fail without warning are often small and easily carried in the vehicle.