1994 Subaru SVX - Starting problem

[KevinC]

Good morning everyone. I almost never write. I read (lurk) occasionally. I am a fortunate man in many ways. One of which is owning three. A 94 Laguna LSI (mine), a 92 Silver LS (hers) and a 92 Silver LSI (our son's, a wreck we hope to rehabilitate, -not our son, the car). The 94 is quirky. Starts, runs fine but won't re-start if left for about 45 minutes. If I attempt a re-start immediately or within about 30 minutes, no problem. Past that threshold no start until much later - about an hour plus. Our son's diagnosis based on reading the codes is a failed crankshaft position sensor even though it doesn't show any of the typical symptoms I've read. It's a discontinued part. I would love to locate one or another answer to this problem.
Happy Thanksgiving in these, our most interesting times.

K.

[Blacky]

Other Subaru crank and cam sensors can be substituted. Sometimes the orientation of the connector is different but they can be used.
I replaced the cam and crank sensors in my '97 a couple of years ago. I'll check my records to see which ones I bought.

P.S. I can't find the receipts for the parts. If you do a search here on the forum, you should be able to find the info.

[Tireiron]

To me it almost sounds like a coolant temp sensor issue. When the engine is still completely hot it is fine, and when it is cold it is fine, but if there is a dead spot in the middle temp range the ECU doesn't know what to do with air control valves for starting.

Are there any odd symptoms when it is running or driving? Any odd loss of power or dead spots? Any stumble or roughness at idle or cruising speed?

[KevinC]

Thanks Tireiron. No other problems. Runs smooth, idles fine.

K.

[irox]

Hi,

Sorry, not entirely clear from the original post, but what does 'not starting' look like?

Does the starter turn over, but the engine doesn't catch, or is there no starter running, is there any clicking, humming, rattling, etc.. More details could help diagnose it.

Thanks,
Ian.

[KevinC]

Good morning Ian. Thanks for looking at this.

When it doesn't start the starter does not turn over. The antenna comes up, the dash lights up. That's all. There are no clicks, no engine sounds.

K.

[LarryIII]

I hate to state the obvious, but have you checked the starter relay? When hot the relay may be faulty.

[irox]

That rules out some possible causes.

So it's likely something in the ignition system (such as the starter relay LarryIII).

Since it's intermittent, and seems related to how long the car is cooling down, if it was my car I would look for plug faults and wire faults. Make sure all connectors are seated properly, wiggle/push in the wires for relevant connectors, check fuses for oxidation or melting of the fusebox.

I once spent many $100s of dollars on parts (including 2 MAFs!) until I realized it was a faulty MAF plug and replaced it for something for like $6 bucks off of ebay. I did have problems starting it cold, and also on extremely hot days (lots of hot angry people who had to deal with my SVX stalling out at least a dozen times trying to get home from work). Which reminds me a little bit about what you are describing (of course you probably don't have a MAF problem, maybe if the car would turn over but not start, but maybe some other plug).

After that, you'll need to get a volt/ohm/(multi) meter and starting testing the ignition circuits to make sure all the grounds are good (very low ohm) and the relevant parts are receiving the correct voltage.

Good luck!
Ian.

[KevinC]

Hi Ian,
I know it's been a while. I looked for the starter relay. Not under the dash as reported in an earlier post from 2001. My SVX has had many owners, an accident and probably some imaginative repairs before I bought it as a parts car and decided to make it mine instead. Is there any way to trace the location of the relay?

K.

[irox]

Hi Kevin,

I'd thought it was near the fuse box under the hood, but then I again I've been luck enough (touch wood) to not have to replace one...

There are a bunch of starter relay mods on subaru-svx.com which involve moving the relay to a different location, perhaps search under the hood.

Also find the starter motor and start following the wires and see where they go.
Once you find the relay it should be easy to test if it's working with a multi-meter.

Good luck!
Ian.

[oab_au]

Hi Kevin, you will have trouble finding then starter relay, as they don't have one.
The US cars have a security relay that gives problems, but from what you say it sounds like the starter solenoid is sticking when it is hot, you can check this by having somebody tapping on the solenoid with a hammer handle, as you hold the key in the start position.
I don’t know how to fix it other than a different starter.

[gbianchi]

You can replace the starter contact, Larry b's automotive starter parts, cheap and fairly easy.

[SVX_MY_BABY]

Originally Posted by gbianchi

You can replace the starter contact, Larry b's automotive starter parts, cheap and fairly easy.

As in https://www.amazon.com/gp/offer-list...192520&sr=1-10

[Trevor]

Originally Posted by KevinC

Good morning Ian. Thanks for looking at this.

When it doesn't start the starter does not turn over. The antenna comes up, the dash lights up. That's all. There are no clicks, no engine sounds.

K.

When an electrical component fails intermittently due to heat as you describe, in most instances this relates to shorted turns within a winding, e.g. within a solenoid, relay or contactor, or electric motor. In each case there will be an excessive flow of current when the item fails to operate. This will in most cases will not be sufficient to blow protective fuses.

Your first approach should be to check for full battery voltage at the starter solenoid when the fault is present. If the voltage is low this will indicate that the solenoid is drawing current beyond the capacity of the supply wiring and shorted turns are a possibility, or that the supply circuit has developed a high resistance.

The latter could mean a connection affected by heat, or more likely provided your car has one, low pressure on contacts within the security relay. This involves a normally closed contact depending on spring pressure thus making it always suspect. Heat could very well be reducing contact pressure.

Intermittent electrical faults become real pain and there are no shortcuts. In your case I would run a temporary wire from the starter solenoid input connection to within the car so that you can immediately check the voltage as and when the bugger misbehaves. LOL The time involved will be very well spent. If you do not have volt meter you could simply connect a lamp and be aware of a change in brilliance. You could then go on to checking for voltage at the actual motor.

Taking account of the above, do you notice any change in the brilliance of the dash lights ?

[KevinC]

Finally, A very smart mechanic I know, Andre at Village Auto Works in Chester, NY solved my persistent starting problem. He installed a secondary push button starter switch in the console and ran a wire from the switch directly to the starter motor. Now I turn the ignition key, push the button and I am off, every time. Thank you to everyone for your suggestions.

K.