INTERMITTENT BAD MISFIRE

[RAY]

Back in June 2011 JAYMANEK from Nuneaton UK   was experiencing this problem and at the time had quite a few replies and advice, but, from what i can see at the time the problem was not resolved. Can JAYMANEK  get in touch, or any body else for that matter, and let me know what the problem actually was. Mine has just started doing the same thing for no reason, nothing has been done to the car.

Many thanks.

Ray

[Tyler S]

Ray, JAYMANEK's problem was a lean misfire caused by a PO's tank coating that had deteriorated and plugged the screens, filters, and pump. If you have gone through checking all the ignition components, then start looking at a fuel problem next. Do a pressure and flow test on the fuel pump. Easiest place is under-hood near the FI pump.

[RAY]

Thanks for the info Tyler, she's in the trim shop right now having a nice new hood fitted.
The problem started on the way there so no other checks have been carried out yet.
Sorry to appear dum but whats a PO tank ?  Might have to get specialist to do the pressure and flow test on fuel pump presumabley a special piece of kit is required ? By FI pump do you mean fuel pump, i thought that was underneath at rear.
Thanks for your time.

[Bonnyboy]

PO is previous owner

I test in three positions - I disconnected the fuel line just before the fuel injection pump - did the test and then checked again after the fuel pump and did the tests and then did it one more time as it was heading back into the fuel tank.   I like the belt and suspenders approach and found a crimped line under the car that I never would had I only tested in one location.  Re the pump I found that my fuel pump gave the volume but not enough pressure.
 
To do the test for pressure I used a 10' piece of garden hose connected to the fuel line with a piece of tube that fit the fuel line and lots of black electrical tape to take up the different diameter of the garden hose that I connected to the garden sprinkler pressure gauge - $.50 at a garage sale

To do a flow test I used same piece of garden hose and a clamp and an old measuring cup in a much larger bucket to catch the overflow. I marked on the measuring cup where the volume should be in 15 seconds and 30 seconds.     $.50 again at a garage sale.

Just be careful with the fuel as it is very flammable.  My garden hose let me put my test station at least 6 ft away from the car.  Have a proper fire extinguisher at hand.

[ja17]

PO is a reference to "Previous Owner".  FI pump is a reference to "Fuel Injection" pump. 

[RAY]

Thanks for all the clarifications guys and the detailed test instructions Bonnyboy. I'l look into it once i get it back, it will be interesting to see if the problem returns on the drive back, about 40 miles and mostly motorway !