head scratcher

Post by **RickHaleParker** » 04 Feb 2018, 18:34

I had a look at the scan tool software and I am going to see if I can get it to work with my dongle, I think it might be a proprietary link with the software I already have.

850 OBD-II Supports: ELM327(1.4b onwards) or USB ObdLinkSX via OTG support. I cannot say if it will work with ObdLinkLX.

You might try asking here.

It began as only being temperature dependent and now appears to have graduated to a time related issue at all temps. Having said that it never happened during warmer weather in the fall.

It does sound like it could be temperature sensitive electronics. Not hard too hard to confirm if you can pin down the right suspect. In electronics I would use heat guns and refrigerants to change the temperature of the suspected components, if the problem came and went with the induced temperature changes, I knew where the problem was. Would be somewhat of a challenge to adapt the methodology to automotive electronics but I won't say .. not possible.

Post by **mrbrian200** » 04 Feb 2018, 20:55

Consider this a plausible theory.
Bad evap purge valve (stuck open)? The intake would be flooded with fuel vapors initially then run rich until the canister also cleared of fuel vapors and/or the engine warmed enough that the ECU starts to lean out fuel delivery.
That would also explain your P0455 code as the system wouldn't hold pressure when the ECU tests the system.
If your idle air control valve wasn't working properly (not opening) this would probably compound matters dramatically.

When the car hasn't been sitting as long the fuel vapors haven't built up enough to result in obvious symptoms.

I didn't sift through every detail in the rather long previous threads. It's possible you've already looked at/ruled out these things. If so, disregard.

Post by **RickHaleParker** » 04 Feb 2018, 22:06

The old electrical mechanical controlled engines had a ballast resistor to give the ignition coil some extra kick when starting, so that one could get the engine started in cold weather.

The '98 Volvo I5 does not have a ballast resistor but they do have the Ignition Discharge Module (IDM) that supplies power to the ignition coil. If the IDM where to become temperature sensitive, it is conceivable the ignition coil primary might not get enough power to start the car.

To test the theory: When in a no start condition, take a heat gun or a blow dryer and warm up the IDM. If it makes a difference replace the IDM. As for why it does start after a long crank, electrical current warms up the IDM .

shegarty · Post by **shegarty** » 05 Feb 2018, 05:13

mrbrian200 wrote: ↑04 Feb 2018, 20:55 Consider this a plausible theory.
Bad evap purge valve (stuck open)? The intake would be flooded with fuel vapors initially then run rich until the canister also cleared of fuel vapors and/or the engine warmed enough that the ECU starts to lean out fuel delivery.
That would also explain your P0455 code as the system wouldn't hold pressure when the ECU tests the system.
If your idle air control valve wasn't working properly (not opening) this would probably compound matters dramatically.

When the car hasn't been sitting as long the fuel vapors haven't built up enough to result in obvious symptoms.

I didn't sift through every detail in the rather long previous threads. It's possible you've already looked at/ruled out these things. If so, disregard.

I had wondered if the evap code could possibly be related. I will look into what it would take to replace this but at this point I am leary of throwing more money at it. I have had the eval code for almost 4 years now but the time dependent hard start has only appeared in the last few months.

Is there a thread anywhere that can help me determine which configuration my 98 is? I don't much relish attempting to locate it in these temps, -18ºC this morning!

shegarty · Post by **shegarty** » 05 Feb 2018, 05:15

RickHaleParker wrote: ↑04 Feb 2018, 22:06 The old electrical mechanical controlled engines had a ballast resistor to give the ignition coil some extra kick when starting, so that one could get the engine started in cold weather.

The '98 Volvo I5 does not have a ballast resistor but they do have the Ignition Discharge Module (IDM) that supplies power to the ignition coil. If the IDM where to become temperature sensitive, it is conceivable the ignition coil primary might not get enough power to start the car.

To test the theory: When in a no start condition, take a heat gun or a blow dryer and warm up the IDM. If it makes a difference replace the IDM. As for why it does start after a long crank, electrical current warms up the IDM .

Started fine for the wife this morning in -18C ... will have to wait for another day to try this. Where exactly would I find the IDM?

shegarty · Post by **shegarty** » 05 Feb 2018, 05:16

Motu wrote: ↑04 Feb 2018, 22:44 I didn't see your earlier thread. In the no start, does it have spark ? Does it have injector pulse ?

It does have spark and from what I can tell injector pulse.

Post by **RickHaleParker** » 05 Feb 2018, 05:39

Where exactly would I find the IDM?

Start at the +12V to the ignition coil and trace back a few inches.

: IDM.gif (30.81 KiB) Viewed 957 times

Post by **RickHaleParker** » 05 Feb 2018, 05:53

I have not done so myself but, I have heard of people replacing the Ignition Coil with IPD's MSD Ignition Coil Upgrade and never having a cold start problem again.

shegarty · Post by **shegarty** » 05 Feb 2018, 09:31

Looks like I won't be able to get the fuel pressure gauge on the car today as the wife has it at work. I will try for this evening or tomorrow morning and post back what I find. I am hoping to find initially higher fuel pressure than last time which was 38psi at the rail before starting.

head scratcher

Re: head scratcher