1999 C70 crank sometimes no start issue

volvooh · Post by **volvooh** » 01 Mar 2017, 09:18

My 1999 C70 convertible is in storage now, but will be getting it out in advance of the summer months shortly. When I put it away I was dealing with an intermittent crank no start issue. I replaced the fuel filter relay but the situation persisited.

The situation is this. Sometimes I will have a crank no start, sometimes a start but only for a few seconds- the engine revs then dies, but eventually starts. This does not seem to be engine temp dependent- and honestly it happens mostly when its cold.

I have heard the immobilizer antenna can cause these issues- could that be the case? I kind of doubted it was a crank sensor as this happens mostly when the engine is cold and I have always had them fail on other cars when its at operating temp.

Also, there is no codes when this happens.

Post by **theWIFES_S70** » 01 Mar 2017, 09:58

What's the order for troubleshooting no starts: Fuel, Spark, Compression?

If it's starting and then dying, you have compression and spark and fuel...

Sounds like you were thinking it was a fuel delivery issue, which is why you swapped out the relay. Did that make a difference? Even for some time? And how's your fuel pressure? What do you get when you press the schrader valve by the fuel rail? Have you tried to prime the system 4 or 5 times before cranking it and does that make a difference?

How's your fuel pump? Is it original? Could be a fuel pump check valve, pressure regulator/damper.

Here's some reading to help you pinpoint the trouble... Good luck!
viewtopic.php?t=73745

volvooh · Post by **volvooh** » 01 Mar 2017, 12:21

Thanks- I changed the relay but the problem has continued to occur. Now I guess I've got a spare! I'm not the original owner, so I have no clue the age of the fuel pump. However, I did test the fuel rail and I get about 50lbs (if I recall- somewhere in that neighborhood).
I'll take a look at your post you pasted. Thanks!