1998 Volvo s70 t5m intermittent spark

Sniperboy80123 · Post by **Sniperboy80123** » 27 Aug 2018, 18:46

My 1998 Volvo s70 t5m has an intermittent spark problem I have changed everything from the coil to the ignition switch but when it starts it runs fine just takes a few trys and its not normal plz help problem not solved check fuel PSI and it ok there is no spark and when there is it fires up. Yes the parts haves been changed do to the problem the parts that have been changed are the cam sensor part#css1552 brand BwD the crank sensor is Su4107 and the is duralast the coil also had been replaced and the part number is c1090 and that duralast the ignition switch had also been replaced and the part number is ls963 that is duralast but it oem Volvo and the maf has been cleaned out the fuel pressure at prime is at 42-45 PSI and at crank its at 35psi and running its at 36-43 PSI with accelerating the fuel pressure was tested with an injectors cleaner gauge but also works with checking the fuel pressure
...Juan

dj_v70 · Post by **dj_v70** » 28 Aug 2018, 13:16

How do you know it is a spark issue?

I would try to troubleshoot vs replacing parts. When issue happens, did you check coil output (crank while coil output is 1/4" from ground) and voltages on both sides of coil (again, while cranking)?

Sniperboy80123 · Post by **Sniperboy80123** » 28 Aug 2018, 18:17

I have checked that it's like if it has a relay or something there is no signal coming from the computer but the u crank several times and it starts up like nothing ever happened is there a relay for the ignition switch

dj_v70 · Post by **dj_v70** » 28 Aug 2018, 18:47

Sniperboy80123 wrote: ↑28 Aug 2018, 18:17 I have checked that it's like if it has a relay or something there is no signal coming from the computer

Could you please explain this differently, I don't understand.

If you could explain the testing that you have done so far, and the results, we can provide feedback on what to try next.

Sniperboy80123 · Post by **Sniperboy80123** » 28 Aug 2018, 18:53

When I am cranking .205 volts from the signals wire from the computer and it spark problem because tested with a spark tester

dj_v70 · Post by **dj_v70** » 28 Aug 2018, 19:13

Ok, so, if I understand correctly, you are getting .2V from the computer while cranking.

a) Where did you measure this? At coil or computer? You want to measure it at negative side of coil. If so, you are close.
b) Do you have 12V on positive side of coil?
c) was spark tester on spark plug cable or on coil output (high voltage) cable? you should test it on coil high voltage cable first.

Sniperboy80123 · Post by **Sniperboy80123** » 28 Aug 2018, 19:37

I have 12 volts I have ground no signal from computer .205 volts there is no spark. No shock no voltage no lights