Fault code reading- 1997 940 HPT.

[Forrest]

In answer to Roger’s original question this is the build diagram for the code reader.

When I made mine I used an OBD breakout box instead of a selector switch in order to reduce the amount of soldering/wiring involved. Same principle though.

[rogerthechorister]

To summarise, we have done air filter lambda sensor (supplied by Trust Car Parts who used to be Braydon, so it MUST be right) Distributor cap rotor arm HT leads and plugs.

We have not done the rear temperature sensor, Steve at Trust says they hardly ever fail. We have not done the AMM yet even though I have one spare.

We are aiming for the injectors. This is because she is a bit lumpy on first cold start. I'm sure I have a spare set somewhere but I cannot find them. Neatly in a sort of tupperware box - but can I find the box? There used to be a member who reconditioned them. Is he still about? Has anyone got a good spare set?

Garage says "general wear and tear" might be the problem but that is nonsense IMHO. I am however insisting that he checks the compressions.

Many thanks for the code reader diagram. I shall now google for the actual codes.

Exhaust leak should have shown up on MoT, even if only an advisory.

I have not had a chance to give her a good run to see if the lambda light comes on again - she just decided she needed a new lower driver side (right hand side) balljoint)

[rogerthechorister]

Injectors done.
AMM done
Balljoint done
Run to Whitstable and back done
Still fail on emissions but less bad.
Garage said better run might do it so I planned to go to Burton on Trent and back.

Made it as far as the car park over the road from my house and then no hot start again!

Garage suspects head gasket but his compression tester was wonky and IDK the figures now he has bought a new tester.

I suspect EGR valve.

Any other views?

[gpl1968]

No hot start after a short run may be the crankshaft position sensor. Check the insulation in the lead (sensor in top of bellhousing and lead connects to loom near the distributor). With age the insulation breaks down and the signal gets corrupted. My last 940 had this problem, first drive in the morning to the newsagents and no start after. a new sensor fixed the problem.

Rich running may be an air leak in the induction system. Have you checked all the air hoses from the Air Mass Meter to the inlet manifold and all the vacuum hoses for cracks/leaks at the joints? Is the intercooler air tight?

[Bugjam1999]

Originally Posted by rogerthechorister

We have not done the rear temperature sensor, Steve at Trust says they hardly ever fail.

They certainly do fail and cause really poor running, especially when starting from cold- when mine failed the car would run on three cylinders initially, then chime in on 4 after a minute or two.

Make sure you get a Bosch replacement, the pattern ones either don’t work or fail pretty quickly.

No need to remove the inlet manifold to replace it (which is what the internet says) just need a deep socket, extension and a wobble joint.

Cheers

[Oneeyeblind]

Bringing back a bit of a prehistoric post here!
Still trying to solve me running problem so have ordered the bits to make my own code reader! It won't be as neat and tidy as the ones previously done on here but it'll work! (I hope)
I'm pretty sure I know how to use it once I've made it but any other advice is appreciated!

Does anyone know of a list I can print and refer too once I have the codes aswell?

[griston64]

Originally Posted by Oneeyeblind

Bringing back a bit of a prehistoric post here!
Still trying to solve me running problem so have ordered the bits to make my own code reader! It won't be as neat and tidy as the ones previously done on here but it'll work! (I hope)
I'm pretty sure I know how to use it once I've made it but any other advice is appreciated!

Does anyone know of a list I can print and refer too once I have the codes aswell?

https://www.volvoclub.org.uk/faq/EngineOBDCodes.html

Here you go