5 pot Volvo 850

[Trist28]

Not S2 but........

I have a 93 Volvo 850 GLT which has a 2.5 5 pot petrol motor. Non turbo. I paid the princely sum of £100 for it and have had great fun having such a budget tank. I have used it for 2 years without issue.

Ive had starting issues on 2 occasions over the last few months but put that down to flooding as it stunk of fuel - and started easily when left for a hour.

The new problem is a little more tiresome though....

Was out and about in it and drove home, parked up and she refuses to start - at all.

I have the following

Fuel pressure at inlet manifold, cranking fine, spark at coil and to plugs
Timing belt fine
Pulled injector rail - injectors not firing. Put drop of fuel in cyls and she fired fine.
Checked all fuses and relays for signs or issues - none found

Would you guys agree it must be cam or crank sensor? If so does anyone know the test methods -I have a multimeter. Problem is to change them both will cost more than I paid for it If it fixes it fine but if it doesn't it spoils my budget motoring!

[UrS4boy]

I have no clue how the Vulva 5 pot ignition/fueling systems work but if it was an Audi, the first thing I would ask would be: "Have you pulled the DTC codes?"

The DTC codes would flag a wonky cam or crank sensor and lead you to a solution.

Obviously this problem existed and persisted before you got the car and the issue was reflected in the selling price (the owner wanted well away from the car). His loss will be your gain if you can figure this out.

Pull the codes.

[K Simmonds]

I'm not sure Tristan can pull the code on it, does it have a diagnostics port mate or have you pulled the codes and not gotten any help?

It's a new problem as he's done a lot of trouble free miles since acquiring it a couple of years ago, if you saw the car you'd understand why it cost so little, the bodywork is shall we say tired?

Great car fun, practical car though so I can understand you wanting to sort it.

Maybe some of the Scandinavian members may have some ideas and knowledge of the systems on the car.

[Ryss]

efi?

[Trist28]

To confirm - Its a 2.4 not 2.5 and has Bosch engine management.

Has 2 ecu, each the same size as a motronic ABY ECU.

The previous poster..... Yes it is electronic fuel injection

[elaw]

I don't know about that engine specifically but a generic suggestion: have you checked to make sure the timing belt hasn't jumped a tooth or three? With some engine-management systems that will throw off the timing between the crank and cam sensors enough to piss off the ECU and make the engine not start.

Another thought: you say it has two ECUs... most likely that means one's for spark and the other for fuel. Since it has spark and no fuel, that means the fuel ECU could be at fault. Is there any chance you can get your hands on a known-good one to install as a test?

[John.]

Do you have voltage to the injectors or is it a switching issue?

[mdz]

850 has a diagnostic unit in the front of engine bay where you plug a wire into socket and watch LED flashing to get fault codes. There's pdf files with process description, fault code list and troubleshooting floating on the internet. I have one about 850 abs system as I once had to fix it, but I can search for one about engine management tomorrow.

[K Simmonds]

He's not getting any voltage to the injectors at all, fault codes would be really useful if you could find out how to pull them it would save a lot of guess work.

[John.]

He's not getting any voltage to the injectors at all,

Main relay or wiring fault then surely, ECU will likely only switch the injectors on that vintage?

[Jamin]

Some info here: http://www.volvotips.com/index.php/8...repair-manual/

[K Simmonds]

Main relay or wiring fault then surely, ECU will likely only switch the injectors on that vintage?

That was pretty much my first though when Tristan ran the problem by me.

[mdz]

https://www.volvoclub.org.uk/tech/service/850/TroubleshootingWithCodes-NonTurbo.pdf

[UrS4boy]

850 Diagnostic Codes

Some info here: http://www.volvotips.com/index.php/8...repair-manual/

Here is the key part of that list:

http://www.volvotips.com/index.php/850-2/volvo-850-s70-v70-c70-service-repair-manual/volvo-850-diagnostics-with-codes-obd/

Here is more:

http://www.matthewsvolvosite.com/read-codes-volvo-850

Here is Figure 1 from the first link (in case it goes missing):

[Trist28]

Thanks for all the useful replies guys - appreciated.

I will get onto the blink codes and see what that tells me.

I will report back