Hello fellow Volvo owners and enthusiasts. My dad owns a MY2000 (W Reg) Volvo C70 2.3 T5 - engine code: B5234T3. We've owned the car since it was only 2 years old, and for it's age I would still say at 83k miles it's still fairly well for it's age. However, a severe problem came around in total of about 5 years ago. The car began to be erratic to drive, the ETS light and EML lights were both on the dashboard. The car was just outside of it's 10 year warranty for the electronic throttle system, which appears to be a very common fault on this series of C70. Thankfully, we took it to the Volvo main dealers and they honoured the warranty work, cleaning the throttle body and remapping the ECU to the new software, free of charge. Since then the car had covered a good few miles, however the fault came back again and we thought we'd take it to another garage. The car struggles to find a nice spot to idle in, it keeps surging between 750 and 1,200 RPM. The car seems to limit at 4k revs (auto box), it hunts and is very lumpy when driving. However we wasn't pleased with the service at all as the vehicle came back worse, so we refused to pay part of the bill and left it at that. The faults are still the same and no different. The car still pulls very well when you demand power. Since, the car has been sadly stored, collecting dust which is a sad sight to see for such a nice motor. I have just finished my level 2 apprenticeship in Motor Vehicle and have been working in a garage for 3 years now, and I thought I'd delve into the car to see if I can spot anything obvious or suspicious. I decided to remove the throttle body only to find the bore with a gapping great crack inside, which lead to the bolt holes. The side of the unit was severely dented and damaged, meaning it could have been dropped or tightened up too tight. I bought a second hand unit, making sure it was the "White Label" and that all of the numbers matched. We were lucky enough to find one. I put it all back together and it ran, but just like before. Without access to a code reader or oscilloscope, identifying any electrical faults alone are proving to be difficult. I'm lead to believe it could be something like a fuel pressure sensor or something silly like that? The MAF has been changed to a new genuine Bosch unit. All help is greatly appreciated

 

fuel, spark, mixture... If you suspect the fuel pressure regulator/sensor, you can measure at the rail's schraeder valve. You didn't mention if there was a check engine light - but you can buy a budget OBD2 reader or perhaps get the shop or Autozone to check for codes. A lumpy idle can be a vacuum leak or a dirty ISV. If you have spark issues, it could be a coil pack gone bad but I'd expect a code to get thrown. Have you inspected the plugs? do they vary cyl to cyl - are they oily/black or dry/tan-gray?

Also check out any articles/posts on retraining the ECU maps. If you put in a different ETB you may need to do that procedure...

 

I did some further investigation on the car. It's been a few weeks since I changed the ETM, however the idle has settled itself now, but it sits at about 1100rpm. It obviously changes as you select drive as there is load on the engine. What I suspected to be a vacuum leak is actually an injector seal, which is creating the hissing sound of a vac leak! I've replaced the new throttle body gasket also. Any ideas where to get injector seals? Thank you