94 850 crank no spark

esachs · Post by **esachs** » 14 Jul 2019, 08:11

Hello Everyone,

I've got a '94 850 wagon standard transmission. It was driving fine to the gas station and after filling up it cranked but didn't start. I tried a second time and it eventually cranked more and more and then fired up, but sounded awful and the check engine light came on. I turned the key off, but the engine kept running for maybe 5-10 seconds until it puttered off. Third try, it wouldn't even crank.

one hour later I tapped the starter solenoid and someone moved some relay wires by the fan shroud and it began to crank but wouldn't start

Its been in my friends shop for multiple days. He said there is no spark. I pulled codes for the cam, rpm and throttle sensor (some of them may be old codes), but I replaced all three sensors yesterday and didn't win. What should be next? Starter switch? a relay somewhere?

any insight would be very much appreciated. You all have such a wealth of knowledge.

Let me know your thoughts,
-evan

Post by **Ozark Lee** » 14 Jul 2019, 10:27

You have a bunch of stuff going on that really doesn't seem to correlate. How is the battery? Check and double check the battery cables and particularly the secondary cables off if the main battery terminals along with the grounds.

The relays on the fan shroud are either the master fuel system relay or the fan relay, neither one really changes the starter circuit so I'm not sure where that ties in.

The way it died actually sounds more typical of a failing fuel pump but that will not result in a no spark condition.

...Lee

Post by **jreed** » 14 Jul 2019, 15:22

Agreed with the words of the master above.
It might be a good idea also to check if the fuel pump is coming on (usually there is a sound from the fuel pump priming when you turn the key just before starting) and if you're getting fuel pressure to the fuel injector rail.

Post by **misha** » 15 Jul 2019, 00:53

esachs wrote: ↑14 Jul 2019, 08:11 I turned the key off, but the engine kept running for maybe 5-10 seconds until it puttered off...

That would indicate ignition lock problem.

greg850r · Post by **greg850r** » 15 Jul 2019, 09:44

I'm with misha, look at the ignition switch. Has your instrument cluster or your turn signals acted up lately?

esachs · Post by **esachs** » 23 Jul 2019, 08:06

Okay. Sorry for the delay here, everyone. It's been a little crazy. The car has been at a euro car shop for about a week now, having waited on an ignition coil from FCP for two days. Turns out that didn't work either.

He said that there is spark and injection at every key cycle but not enough to get going fully. The mechanic is now leaning towards the EZK ignition module or the fuel injector module. He wants to start with replacing the ignition module first.

Does anyone recommend a good place to find such modules in case I can't get them locally? Whats a good price?

I sure hope this all works. It's been two weeks!

-evan

Post by **erikv11** » 23 Jul 2019, 08:29

For fuel I'd replace the fuel injector relay first. Cheap, easy, common problem. Get one at the junkyard.

The ICM (ignition control module) is that little black box on the coil, they come as a unit, he's already replaced that.

esachs · Post by **esachs** » 23 Jul 2019, 12:07

The mechanic said that he tested the relevant relays, including the fuel injector one.

And I think he meant to say, and I meant to post, that he is looking to replace the EZK ignition computer ecu first, and then if that doesn't work, the fuel injector computer. What is the proper name for these parts?

Post by **erikv11** » 23 Jul 2019, 12:52

OK I did understand about the fuel injector computer, not sure what is the proper term for it either.

Just a warning there is a mantra on this site: "The problem is not the computer, it's never the computer. Except for the rare cases where it is."

It does sound like the tech has checked out many things, and is only trying what I might call the the ECM (EZK computer) as a last resort. If that's the case, it seems reasonable. Because it is exceedingly uncommon for these to fail, the best source is a junkyard, or you could try Erie VoVo or another regional dismantler. Be sure to match up the engine management systems, or it will not work. Your mechanic will almost certainly get the computer(s) from the yard if he sources for you.

What is your area, so that any NE members can suggest a junkyard with 850s? And know what they are getting for old 850 computers? May need to just call Erie, they would supply the right part too.

Along those lines I would definitely first check the electrical portion of the ignition switch (https://www.fcpeuro.com/products/volvo- ... er-9447803), especially if it is going to cost you a lot to have the ECM swapped. It is very common for these to go out after 20 years (they basically all fail by now - has it ever been replaced before?) and when they do is can cause a lot of erratic and seemingly nonsensical behaviors. The comment from misha is a good one.

Post by **Ozark Lee** » 23 Jul 2019, 21:44

On a '94 NA the system is a Bosch LH 3.2 Jetronic system with an ignition module and a fuel system module. I think some of the older Porsche variants were called EZK but that is technically not correct for your car. Trying to search for an EZK module for a Volvo 850 will lead to no results. I have only encountered one bum ECU in my life and it was because I murdered it when I lied to the VOL-FCR diagnostic program and told it that a '99 model was a '98 and started to send commands to clear codes. It wrote bad code to the ECU which was not compatible with the program.

Do you have any idea what codes are coming up on the OBD-1 ports form A-2 and A-6? The OBD-I system on that car is great, it actually gives you more precise information that the OBD-II.

...Lee