hi hopefully posted below are 2 pico captures of both primary and current waveforms from a ford maverick that a customer has problems with.the car has intermittent non starting issues normally from a warm engine after it has stood for maybe an hour or so .it cranks normally,no lights are illuminated on the dash and usually starts as soon as the aa arrive!crank and or cam sensors were suspected but after extended scoping i could not condem either.lamda sensor was slow in switching but found fuse blown for the heater which resumed nearly normal service to the sensor.glitches in the scope image led us to the ignition to look for a misfire.the images on the links are of cyl 1+4 and 2+3 primary and the common current draw at idle and again at 2000rpm.at idle it looks like the current is being interrupted for a second time shortly after the initial spark is that a second spark?as soon as the revs are increased above 1500-1800 revs the interuption disappears.have tried other coils and swapped relay checked plugs and am coming round to condeming the power transistors for the coil windings in the ecu.would be grateful for any input or views on the patterns ,hopefully they downloaded ok my thanks to andrew west for his help on that score.the misfire may not be the answer to my initial problem but it surely needs addressing .if it is the ecu that needs renewing would second hand one plug and play or would it have to be matched to the immobilizer.thanks in advance paul

Are these the readings your getting during the non start period Paul?

thanks for quick reply .the answer is no. the one showing the double take is at 750/800 rpm the other is 2000 rpm both engine warm. when starting from cold the idle capture is normal until 2/3 mins after start up then the misfire becomes evident.typically it has not failed to start with us yet.thanks again paul

You may have to keep the car at your work place until you will get the non start issue,Then you will be able to narrow down the fault much quicker,

It could be a fuel pump issue!

Thanks I may be able to keep the car until fault recurs but either way I would like to know what is happening in that scope pattern at idle .i will try a fuel flow/pressure test on Monday but don't expect my misfire problem to come from there.the scope pattern surely can't be correct but how do you interpret it regards paul

Hi Paul

No help with the non start I'm afraid ..
Check out these two threads ref the multi strike though.

http://members5.boardhost.com/ukautotalk4/msg/1350310315.html

http://members5.boardhost.com/ukautotalk4/msg/1192218032.html

Regards Tony

thanks for the info tony very interesting and enlightening,if disappointing. thought i had it sorted but back to the drawing board .will have to wait till problem reappears and have scope to hand.cheers paul

I have had some problems like this with other vehicles when the fuel pump plays up & appears to be working but send fuel up the return. I know.... but we have proved it. Gave us the right run around because it always broke down or went into non start away from the workshop & by the time we attended the break down it started 1st time until one day we got it to happen in the workshop. Just a thought.

Paul it may be worth asking your customer to check the immobilizer light to see if its going off when the key is switched on,
And also scan it for faults,
They can give trouble in those things,

Hi

To classify this as fixed or not resolved etc in point of fact the owner is still driving it around and has not been back in touch with any feedback good or bad. We commented to the owner that when the fault had seemed to appear the extra carpet on the drivers side had ridden up and partially depressed the accelerator. Re positioning the carpet returned the pedal and car eventually started.he added that the AA man had done something similar and started the car. We could not always recreate the conditions and could not draw any conclusions.