ISnt an XC90 specified for RON 91 gas (our 87 octane)??

Can you show the other four cylinders? Im amazed that only one would detonate - that in itself would make me think bad fuel injector or ????

Whoa!!!... I thought I read he had a bad fuel injector relay... I apologise guys..it was the othher 850 ..crank but no start...

... me. In addition to the PCV job, I repaired bad Fuel injector O rings, Rotted hoses, put a clamp on the breather hose ...

... mounts 2010 rear struts and mounts *2010 one bad fuel injector 2010 plug leads (they were fine - the injector was the issue) ...

So I got the new fuel relay installed and started the Volvo up. Started ... with a similar issue. On of the posters suggested a bad fuel injector relay connection. The problem is, its not on top of ...

... whatever you want to call it. It's getting fuel just absolutely dumped. It performs like it's ... Here are my engine mods: ARD Green Tune Blue injectors AEM Dry Filter Silicone IC Hoses SAS Removal ... solve it either. I thought maybe it was a bad fuel injector, as I had a plug that was absolutely ...

Pull the number 4 injector plug and check it for corrosion. Trace the wiring ... without a voltmeter (DVM) or even a o-scope. The fuel injectors are fired by grounding through the ECM, ... while up you wiggle wiring. Wiring is top suspect Bad fuel injector...test by swapping number 1 and 4 to ...

... much convinced me that the problem lies in a bad fuel to air mix, which causes the valves to get hot. Likely a bad fuel injector or intake air leak.

I had the same symptoms and it was a bad fuel injector. Bought a cleaned set on eBay for $100'ish and it's started on the first turn every time.

... tracking down the issue with poor starting (bad fuel injector) and fixing a few other minor issues, I've just been driving ...