No Spark Gurus - What to do when you've tried everything? Topic is solved

nightdrive · Post by **nightdrive** » 03 Jul 2016, 06:34

Well, almost everything... Have been searching the internet for almost 2 weeks and trying everything to fix my '97 850R wagon.

It started with a fuel pump failure in cold morning weather that was replaced roadside. All went together smoothly but car still wouldn't start so I had to tow it home (damn Saturday rates). After buying a multimeter, testing this and swapping that from a C70 it still won't go. Have audible fuel pump working noises, fuel pressure and working injectors (can see mist when plug is out), but no spark.

So far the list includes:

- Recharged battery (is recently new)
- Checked spark plugs (not wet, fine condition), leads, distributor cap and post (replaced post cause it looked a bit fried, cap is same)
- Tested spark by grounding on block and operating ignition both from spark plug and lead coming from coil - no dice
- Checked crank sensor - 300 ohms resistance so it should be alright
- Checked cam sensor - within spec and also swapped for one off working C70 (worked when put it back on the C70 too)
- Checked coil setup - within spec and also swapped for one that was supposedly off a working car. Still no spark. Also has battery power from plug.
- Fuel pump relay is fine, also tried with one from C70 and jumping using wire.
- Checked J relays - seemed fine but tested with those from working C70. No difference. However it was only the outside 2 that I swapped as I figured the middle one was working due to fuel pump etc working. Maybe that one should be swapped too?

So my last question is - I've read that if the starter motor is shot it won't crank fast enough to send signal to the crank sensor and therefore won't let it tell the ecu to spark. Any truth to this or more internet stories? When holding the ignition on it starts to make an uncharacteristic whining noise but can see all belts moving.

Needless to say this is a frustrating mystery that needs solving! Any help appreciated and I'll post back with the fix for future ref.

Post by **MadeInJapan** » 03 Jul 2016, 10:41

Oh wow! I'm racking my brain here... Starter motor is suspect. Sort of a pain to replace but that may be the quickest route. Can you get the one from the C70 donor car to try? I do think that the whine and not enough of a signal to the plugs may be your issue. Could also be an ignition key problem. I had all kinds of crazy things to sort out on my S70. In my case, the starter motor would not stop...I had to install a suicide line for awhile that I disconnected after the car started, or it would make a "grinding noise." It all sorted itself out when I replaced the starter, found a bare wire that was grounding itself under the starter and a replacement of the mechanical portion of my ignition (where you insert your key)... Just for kicks, lock and unlock your car 3 times at the driver's side with your key, get in your car, put your key in the ignition and wiggle it about, put it up to position II, wiggle it some more and then try to crank your car (just trying to take the immobilizer and ignition switch out of the equation).

Post by **erikv11** » 03 Jul 2016, 11:19

Did you check for spark, or are you deducing there is no spark because it won't fire?

Immobilizer is a good idea.

If there is actually spark, I would definitely check for lawn mower syndrome. You can check compression, and/or just add 1 teaspoon of oil into each cylinder, then crank until it fires. May take a long stint of cranking.

nightdrive · Post by **nightdrive** » 03 Jul 2016, 16:21

Thanks for the replies, will try the lock/unlock trick this evening. Failing that it's starter motor test time.

No spark is seen when doing the arc test from two different spots (from spark plug and from lead running from coil). Can also see fuel misting when the ignition is cranked and there is no plug in a cylinder, so that's why I didn't do the oil/starter fluid thing.

Post by **misha** » 03 Jul 2016, 17:04

Master fuel injection relay.....the grey one on cooling fan carrier?Did you checked it's connections?
Immobiliser disables fuel pump relay...as far as i remember....not ignition coil.

How did you checked cap & rotor....visually?

Post by **MadeInJapan** » 03 Jul 2016, 20:01

I thought about spark plug wires being out of order, but then he would get a spark, it just wouldn't be in the right firing order (and the car still wouldn't start...so I think it's one of two problems. 1), starter motor or 2), immobilizer. Hopefully locking/unlocking with a key 3 times clears the immobilizer, or you can disconnect the battery and touch the + and - wires together. Awaiting what was found! (if you do the later, make sure you have your radio code!)

Post by **jreed** » 04 Jul 2016, 06:14

+1 to misha's question about the cap and rotor... It's interesting that the rotor looked fried but the cap was OK. What brand of distributor rotor did you install?

nightdrive · Post by **nightdrive** » 05 Jul 2016, 04:55

Annnnd I'm back! Unfortunately it's not a triumphant homecoming - fkn thing still won't start.

Tried the lock/unlock trick several times, touched battery terminals and no change, so that maybe rules out the immobiliser issue. Also swapped all the J relays and checked all the fuses now. Including swapping out the relay that sits on top of the radiator and the big ones next to the fuses. As a last ditch effort tried the oil teaspoon trick but again no change.

Still no spark from coil when trying to arc it out but still has power to it. Tested the crank sensor - 300ish ohms still. Didnt bother testing the cam sensor again just cause I didn't have someone to crank it for me (but that was already swapped out and nothing happened).

Also inspected the ECU's - they look fine but can't swap them as the C70 has a weird cone bolt holding the cover on that I don't have a tool for, it's late and most people also don't think it's the ECU.

As far as the distributor post goes - visually checked it and replaced it with a new one of some aftermarket brand that seems to be good quality. Won't work without spark going to it anyway so I don't think that's it.

My mechanic friend who normally works on it seems to think it wouldn't be starter related too. Will probably take it to their shop Friday but really wanted to avoid that as wasting money sucks. Not ready to throw in the towel yet so if anyone has any last ideas I thank you in advance for sharing!

Post by **MadeInJapan** » 05 Jul 2016, 07:13

I'm thinking the cap and rotor are suspect at this point. You changed 'half" of that setup and there is no spark to the plugs...hmmm, I'm wondering if the rotor and cap are different enough that they are misaligned. These are not very expensive parts or you could get them from a donor car- like the C70. I'd pull them from a car that you know runs (you can always put them back in that car once you've established this is or isn't it)!! In fault tracing it's typically best to go from the actual problem area (spark plugs getting no spark) and follow that route back to the cause one by one (unless you have a good idea on the root cause- like immobilizer or starter motor)- the next step would actually be the wires (but how could all of the wires have no current in them?)...so the the next point back would be this cap and rotor! Good luck!!

Post by **misha** » 05 Jul 2016, 07:23

I agree with MiJ on this.
Cap and rotor are the main suspects in this situation.
Btw....is fuse no.1 for ecu ok?
Also check the fuse for fuel pump....should be no.2.