98 V70 awd Hard start I have tried Everything please help

stickbrick · Post by **stickbrick** » 28 Feb 2013, 18:04

Hello All
So I have a 1998 V70 AWD Over the past year it has developed a hard start issue after running and being shut down for 5 to ten minutes. For instance First start of day fires right up no issue stop for a cup of Joe Hard to restart.
If I shut it down and start back up right away its fine
let sit a few hrs its fine

NO CEL
Here Is what I have tried so far.
Coolant Temp sensor
Fuel pump
Full Tune up
Cam And Crank sensor
Mass air
tried disconnecting the Mass air sensor
tried Disconnecting EVAP Hose

Post by **jimmy57** » 28 Feb 2013, 18:09

You need to check fuel pressure. There is a schrader valve (tire valve) on the fuel rail and cheap fuel pressure gauges can be had at Harbor Freight and some auto stores. Tire gauge can even be used but it will likely kill the gauge since they do not make tire gauges to withstand gasoline.
The check valve on fuel pump or the fuel pressure regulator that is down behind engine right at firewall are the things that will let the pressure drop. When the engine is hot and loses fuel pressure the heat of engine will make the fuel that comes to fuel rail vaporize. The engine computer dispenses the correct amount of liquid through injectors. The vapor is not going to make engine run, way too lean.

stickbrick · Post by **stickbrick** » 28 Feb 2013, 18:49

Excellent Reply I will try this this weekend Makes perfect sense
thank you

stickbrick · Post by **stickbrick** » 02 Apr 2013, 13:53

I know I am Bit late but I replaced the Regulator and still no Help any other ideas

Post by **jimmy57** » 02 Apr 2013, 14:07

Did you replace it for a reason or as a try? what was fuel pressure test results? If it holds fuel pressure for 20 min then it isn't a fuel loss issue.