Code 15 on '89

[Marccus]

'89 w/437K

It's been raining off and on, heavy at times in the SF Bay area. Engine was running fine then after about a week of rain, the engine started acting up.

When I first start it, the idle goes to 1K and then the engine dies right away. I have to start several times and goose the throttle to keep rpm's at 2K or so, and then VERY slowly lower the throttle over 5 min or so to 1K, making sure the engine doesn't stall (sometimes goosing the throttle back up and lowering it again).

If I do this and wait about 10 minutes while it idles OK at 1K, then I can put it in gear and go.

If I don't do this, it will just stall again while attempting to engage, or 50 feet or so after driving.

I ran the codes and I get Code 15:

PCM Read Only Memory (ROM) test failed

Water pump, CPS, and timing belt replaced about 1 year ago; PCM about 8 months ago (when trying to find out why the secondaries won't open - still can't can't get them to open

 

[Marccus]

Sorry, hit the wrong button and didn't finish my post.

.. starter about 6 months ago.

Ran fine for about 6 months straight until this problem.

Checked all wiring and I use a lot of dielectric grease on all electrical connections so as water won't be a problem.

Plug wells are dry as I seal them off from water using a silicone gasket sealant - spread gasket sealant under and on top of rubber washer; tighten down the chrome washer bolt just a bit until the the sealant squishes out, then when the sealant has finally hardened, tighten down the chrome washer bolt .

This procedure will form a water / oil tight seal around the chrome washer bolt and the rubber washer so as to make this point of entry impervious to anything draining from the valve covers.

Then clean around the washers for "aesthetic" reasons.

Been doing this for 15 years and have never had a water or oil in the wells.
Is the PCM or CPS on its way out?

Should I just wait it out until we have a week of dry weather.

 

[CademiaX]

15 (O) No Keep Alive Memory power to PCM pin 1 or bad PCM (Memory Test Failure)
(M) KAM (pin 1) was interrupted (was battery disconnected ?)

I think that just means you disconnected the battery...

 

[Marccus]

Well, I had disconnected the battery before I ran KOEO test as part of my check to ensure all connections were firm and tight.

Isn't that OK? - or do you have to restart the engine before running KOEO if one does disconnect the battery.

So is that all there is?!!

Or are the results of the test invalid because of code 15.

So I guess I have to run it again.

Thanks.

 

[SHOtime2511]

437K miles...thats sweet!

 

[mooseSHO46]

x2 437k that's awesome I hope you figure it out man