V70 -98 starts and then dies and 850 -96 stops when warm

[nigiz]

Hello!
I have two volvos with problems.

V70 -98 10-valve:
When i start car it starts but dies immediately. But it wont do it every time. sometimes it just starts fine. I have changes fuel pump relay and lots of other parts. But i have traced that it has something to do with immobilizer. I have tested to change immobiliser antenna ring and bottom of ignition switch. Also tested with another key.


850 -96 10-valve:
Starts and runs great. But when it warms it starts to struggle and then stops, it wont start until it has cooled.
I have tried to change everything. lambda, camshaft and crankshaft position sensors, fuel filter, fuel pump, fuel pump relay, relay and box over radiator, distributor, coil, ecu

[rspi]

Hey, it would be best for you if you posted two separate threads. Have you scanned the system for error codes?

V70... did you REPLACE the antenna ring? If so, the connector may be worn.


850... Codes would help. When it fails to start, what is missing? When it struggles to run while hot, does it run good while moving or does it only struggle at idle (at a stop). Could be a problem with the ECT.

[nigiz]

V70: Yes i replaced antenna ring. and i also checked that black security box.

It cranks whenever i want and starts everytime but sometimes it just stops after 1-2 seconds. Sometimes it has to be started like 15 times before it runs well.

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850: When it reaches normal heat few moments after it sounds and feels like it runs with 4 cyl no matter if i rev on idle. after 20sec it gets worse and it stops and it i try restart it might start and run like with 3cyl 10-20sec and then stops.

Coolant temperature gauge seems to work like it should so it is hard to believe that fault would be that but tomorrow i will try to change it. And i don't believe that thermostat would cause this kind of problem.

[misha]

I would check the chipped key for v70 or to cut another one.Reputable locksmith can do this nowadays without problems.
Could be that it have intermittent signal transmission.
About '96 850.... I agree with ECT suggestion by rspi.

What are the codes from both...V70 & 850?
Since they both produce flash codes...being a 10v cars,you have a full detailed instruction on how to build a flash scan tool reader on your www.volvoforums.org.uk.

[scot850]

On the V70, has the ignition switch electrical portion ever been replaced? When I had one failing on one of V70's I would get all sorts of weird warning lights, and sometimes no lights but rough running. Re-starting the car would sometimes have it run fine till next time. If it was the immobilizer on a chipped key I would not expect it to turn over at all. Do you have a second key and do you get the same issue with it?

Agree with the other guys on the 850. Sounds like the ECT may be failing or at least the connector. There is a thread somewhere which gives you resistance values for various temperatures you can check at the connector. The wiring on the connector by the power steering pump often gets brittle with age.

On the 850, also check the distributor cap condition, and that there is no oil leaking into the distributor from a leaking cam seal in the base.

Neil.

[oldvolvos]

The problem of the car dying when warm sounds like the problem I had on my V70. It was the air mass sensor. I think you can test that by disengaging the connector and trying to start the car when cold. If it does the same thing as when the sensor is connected, it indicates that the sensor is faulty.
As I understand it, the sensor increases the air flow when the engine heats up, meaning that you get less fuel in the mixture. When the engine is warm, a faulty sensor will lead to too rich a mixture for it to run on. If you check the spark plugs, you might see that they are black.