V70 S70 Fuel injection problem.

Greetings all, I have a 1997 V70 20V with 248,000km. I developed after washing the car a really bad miss or what I thought was a bad miss followed by a really bad smell. My mechanic found that number 1 injector was pouring the fuel in at max volume ie the solinoid was fully open all the time. This caused the Lamba Sond light (L) to come on. He then warned me about the dangers of washing 850 / V70 motors - they don't like water particularly. After much mucking around, new plug wires, distributor cap and rotor (all were original and needed replacing anyway). The problem was still there. He removed the ECU for the Fuel Injection and cleaned the contacts and this solved the problem.

But only for a week, and the first sign of uneveness of the motor at idle in gear started again. Then the light came on, then back to the rotten egg gas. After checking for any shorts and resistance problems and going through everything thoroughly, the only thing left was a new ECU for the Fuel Injection. $960 Australian plus labour, and this solved the problem.

But only for a week (1100km), and the problem was back, number 1 injector again filling number 1 pot with fuel. Because I was now 350k's from my mechanic went to Volvo in Brisbane who squeezed me in and found the fault was in the wiring harness. There was a bad connection (intermittent) in the wiring loom. The problem area was between the bottom of the electric fan and the engine. There is a part of the wiring loom which goes into a square shaped section for about 10cm - and the problem was there in one of the connections. $125 later the problem was all solved.

I'm not annoyed with my mechanic because he spend a huge amount of time on this intermittent fault, and there was nothing more that could have been checked out. When we discovered exactly where the problem was, you could make it run perfectly by moving the harness, and then you couldn't get it to play up again. I just thought this information might be useful someone else in Volvo-Land who doesn't now need to spend $1500 when $125 would do fine.

My mechanic paid the Volvo bill, which was very good of him. Also he changed the oil (fully synthetic) each time, just to make sure that the oil wasn't too contaminated by all the petrol going through (and it was a lot of petrol). And when he did a compression test all five cylinders came to

170psi. Not bad for a motor with 248,000km.

Happy motoring. Jeff

Reply to
Jeff Savage
Loading thread data ...

Thanks for sharing

Reply to
Wiwat Chang

Definately worth knowing and a starting place to start looking for the cause, if you have strange short / open circuit type faults with the fuel injection eg an injector stuck open all the time.

Tim..

Reply to
Tim (Remove NOSPAM.

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.