1994 850 temperature gauge goes up, won't start

Volvovlo · Post by **Volvovlo** » 03 Oct 2014, 17:29

I have an automatic 1994 Volvo 850 with a 2.4 liter non-turbo engine with 377,000 K's on the clock... The car has great difficulty starting and when I turn the ignition on, the temperature gauge goes all the way up then drops down, the engine will turn over but usually doesn't start. Once started it runs for ages, I even trusted it to drive all day and it did, until I was on my way home and it stalled, wouldn't start until the next day. Basically,

Last Sunday was the first day I had trouble. I had a misfire and was testing the wires going to the injectors with a multimeter, then went to start the engine and it turned over but wouldn't start. The temperature gauge shot up, and dropped back down within 10 seconds. I got the AA around and they sprayed some Easy Start into the air intake and hooked up some jump leads to the battery, the car started up straight away and ran perfectly. Misfire was gone too (Turned out I just needed to wrap HT leads in more tape than what was already on there). Just as the AA man was leaving, I shut the bonnet and the engine stalled. So we started it up with the key and it started, shut the bonnet and the same thing happened, it stalled. He checked if the bonnet was touching anything in the engine bay and it wasn't, so he left. If we shut the bonnet slowly, it didn't stall, but sometimes it affected the revs. As soon as the AA left, I turned the car off, and attempted to start it but it wouldn't. After lots of persistence and frustration about half an hour later it started. I left it running for almost 3 hours, broken up into 2 hours driving and 1 hour idling. I only turned it off to get more petrol, and it started up again. Was fine for the rest of Sunday, and after Sunday the bonnet never affected the engine again.

Monday morning it started first time and every time so I drove it most of the day, I thought my problems were over. But on the way home on Monday evening while driving up a steep hill, the car stalled and the temperature gauge went all the way up, and the cooling fans came on. I let the car rest for 30 minutes and when I went to start it again the temperature gauge went up and cooling fans came on, and it wouldn't start. I let it rest for longer and when I touched the engine it was COLD, but when I went to start it the temperature gauge reads HOT and the fans came back on. I ended up disconnecting the fan and trying to start it until I drained my battery. I called the AA again, and got my car towed home and put the battery on charge.

On Tuesday morning the car didn't start, turning over as usual with the temperature gauge going up all the way, but the fans didn't start up this time. I spoke to a mechanic who wanted $600 to change HT leads and plugs and thought that was the problem. I doubt it's that. Tuesday afternoon I went back to the car and it started up first time, so I turned it on, and off, and on ETC and it started every time. I then took the distributor cap off to have a look, stuck it back on and it wouldn't start. The car hasn't started since then.

Either Tuesday or Wednesday I visually checked the number 1 and number 2 fuse, which control the fuel injection and fuel pump. They looked fine, I also checked the fuel relay, which has a thing inside that moves as it should, checked the coil for a spark and it sparks, as with the spark plugs which also spark, so the engine gets a spark. I checked the fuel injector rail multiple times and there is fuel in there under pressure, so fuel is getting into the injector rail but not into the cylinders. The next thing I did was go onto the internet, Youtube and a range of different forums and many people had a similar problem with the temperature gauge going up and the car not starting, and said it was the water temperature sensor. Some even said they replaced it and it worked. I couldn't take the thermostat housing off to get to it so I tried to get the sensor off with the thermostat housing on and after about half an hour I did get it off, after using various tools in odd ways.

So on Thursday, I ordered a new water coolant sensor and spent the rest of the day tearing my hair out, swearing and cursing while I waited.

On Friday it arrived, I put it in and the car would not start... Temperature gauge goes all the way up and drops down, no fan, engine turns over, so I sprayed a ton of Easy Start in it and it started on that, ran for a few seconds then died.

Today (Saturday) I checked for any loose wires, pulled the distributor cap off again, used a multimeter on the crankshaft sensor after watching a youtube video (I got a reading of 279 or something on the setting 2000 Ohms, don't know how to use a multimeter) and even tried another battery in my car, and it will not start... Sprayed some more easy start in it and it ran for a few seconds.

I have checked fuses, relays, spark plugs, HT leads, fuel rail, battery, distributor, wires, water coolant sensor, crankshaft sensor and any other logical component and I don't know what it could be??? I'm wondering if it's some temperature sensor somewhere giving the computer a false reading and not allowing it to start? I have not had a reliable working car for a week now and I don't know what to do or what to try next. I haven't put the car on a computer and I don't really want to go down that road. Can anyone tell me what they think it might be? I don't have another car that I can use in the meantime, so I would really like to get my one working again. Thanks to all who can help!

Post by **Ozark Lee** » 04 Oct 2014, 06:49

Does the idle air control valve buzz when you have the key in position II? The Idle air control valve is tied to the same master fuel system relay that provides power to the injectors. That relay is located on the fan shroud and closing the bonnet would jar it. The relays can go bad but it is more typical for the wiring in the relay socket to get messed up. A voltmeter check for battery voltage on the green wires to the injectors will tell more.

You need to read the codes in port A-2 and A-6 and post back the numbers. New Zealand got the European versions of the car I think and they are typically a model year ahead of the North American versions so we will also need to figure out which ECU you have. Reading the codes will help with that.

Is this a 10 Valve or 20 Valve version?

The code numbers should help us help you but the voltage reading at the injectors might help more.

...Lee

Post by **abscate** » 04 Oct 2014, 06:54

Misfire was gone too (Turned out I just needed to wrap HT leads in more tape than what was already on there).

Tape won't work on HT leads long term. You need to go through all your ignition parts and bring up to recommended maintenance.

You probably have more than one issue - you won't find a 'magic bullet' here.

Volvovlo · Post by **Volvovlo** » 04 Oct 2014, 16:12

Something buzzes when I turn the ignition on, here is a video:

Got some codes,

A1: 1-1-4, 1-4-3
A2: one flash
A3: 1-4-2, 3-1-2
No A4 for some reason
A5: one flash
A6: 1-4-3, 1-4-4, 1-2-3
A7: one flash

The only one I can see being the problem is 1-2-3, coolant temp signal faulty, but I have already replaced the water temperature sensor so it must be something else along that wire that's not right.

This is a 20 valve version, with about 5 horsepower left from the original 170. The car was originally sold new in Singapore, so it has been imported to New Zealand. I'll try to measure the voltage at the injectors soon, I'm not fully sure how to use a multimeter, I just guess and watch Youtube videos.

As for the HT leads, I'll look at getting a new set soon, I think the old owner was a bit cheap on maintenance. I've only had the car 5 weeks, I'll see if I can get it started first!

Post by **Ozark Lee** » 04 Oct 2014, 20:42

I'm not sure what the ticking sound is. The buzz you are looking for is heard under the bonnet, just under the throttle body where the air hose goes into the intake manifold. The battery is about dead but I'm sure you know it.

Try to clear the codes and see which ones come back. The ECT sensor code may be left over from before you changed it.

You have the Yazaki instrument cluster and most of us don't have a lot of experience with it since they are fairly rare in North America. The temp gauge thing may be a fluke in the cluster.

The way to measure the green wires is with the meter on DC volts, the red wire plugged into the green wire side of the connector and the black wire on the negative battery terminal or the block.

With the key in position II you should get battery voltage which, in the current state that he battery sounds in, might be around 10 or 11 volts. Zero volts or near zero volts is a problem.

...Lee

Volvovlo · Post by **Volvovlo** » 05 Oct 2014, 00:54

Yes there is a faint buzz. The ticking sound is the seat belt reminder. As for the battery, that's drained from trying to start the car all week. I have a battery charger but it doesn't seem to do much.

Cleared codes (I think) and I get all the same codes back again. I pressed the black button for several seconds to clear it, as stated on another forum, not sure if it's the right thing to do?

I still think the temperature gauge has something to do with the car not starting.

Multimeter comes back with -6.6 or 9.08 depending which setting I use it on (I will have to look at the instructions to tell you what setting that is)

Thank you

Post by **abscate** » 05 Oct 2014, 04:26

You should use Bougicord brand for those plug wires, and no other. These cars are finicky about their ignition parts as many here have found.

Post by **precopster** » 05 Oct 2014, 05:34

Next to the coolant reservoir is the plastic box which contains the transmission and engine ECUs. At this stage with all the codes and strange behaviour I'd be removing the engine computer (the one that says "Bosch" NOT Temic) and cleaning the edge connector with electrical contact cleaner and a toothbrush.

Disconnect the battery first before doing this and let us know how you go.

Volvovlo · Post by **Volvovlo** » 06 Oct 2014, 01:14

I don't see any ECUs by the coolant reservoir. I'm getting a mobile mechanic around tomorrow to look at it, so hopefully he can fix it and if he does I'll share the result. If he can't, I'll think about selling/scrapping it, which I don't want to do because everything else works on it, and it's in fairly good condition. It would be sad to think some minor electrical problem that can't be diagnosed brings down an indestructible car (minus electrical faults) with 377,000 k's on it, because everything still works on it, engine, gearbox, even the seats aren't ripped to shreds yet.

Post by **abscate** » 06 Oct 2014, 03:21

Diagnosing stuff like this really separates the "mechanics"from the "guys who can unbolt stuff and bolt a new thing on". The ECU is under a cover in a box that sits in front of the coolant reservoir. You need to lift the lid off to see.

I would be checking the wiring on the ETC carefully. The ETC function is critical for cold starts as it tells the ECAu how much fuel to meter. The fact that you have wierd ETC function and a no-start is not conicidental