V8 5.2 in Laredo but...ECU is not working

Just a wild guess, but have you connected the oil pressure safety shut off? There is a switch on the oil pressure sender that will cause the engine to shut down after a few seconds of seeing no oil pressure.

Other than that, I am not sure about the need for two computers to run things.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >

If this is the case, then ask the $tealer$hip to disable the alarm system in the PCM you do have. If they have any sense, they will refuse to work on a highly modified vehicle, but it is worth a call.

Earle

Once a PCM 'learns' it's installed in a vehicle equipped with VTSS, it can't be disabled. At least not at the dealer.

There is no such switch.

There is on my Jeep too...

Mike

philthy wrote:

The OP has a Jeep.

Not from the factory.

The PCM learns the alarm configuration when it's installed. Once it sees it, it always expects to see an "OK to run" signal from the alarm module or BCM, depending on the year. If it doesn't see it, you aren't going anywhere.

That's how it works.

What are you talking about?

It most 'certainly' does have an oil pressure safety switch!

On my CJ7 that switch is used to control the manifold heater and the electric choke.

Mike

bllsht wrote:

That switch is only there to keep from powering up the choke heater with the key on and engine off. It's not a safety switch by any means, and won't prevent the engine from running with or without oil pressure.

You of all people should know this after your engine rebuild fiasco on Jo's YJ, which uses the same system.

That is a far cry from 'there is no such switch'. On mine it does not prevent the carb engine from running, but it prevents burned up parts and saving a wiring or choke fire from happening would be called a 'safety' switch in my mind.

I was under the impression, maybe mistakenly, that this switch was also a shut down switch for the FI systems if they don't see oil pressure after a certain amount of time.

Mike

bllsht wrote:

A far cry from 'there is no such switch', eh.

And just FYI, Jo's old 'Nuttered' (no computer) YJ 258 engine that I helped her rebuild in my driveway in a snow storm a few years back is still running very strong and just passed another emissions test with flying colors.

If that switch had of controlled the engine, it would have saved a couple scary moments when we realized it had no oil pressure. No harm was done because someone forgot to read the directions on the oil pump, we caught on fast.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06 (More Off Road album links at bottom of the view page)

Hi,

Mr. "bllsht" where I can send you prive E-mail ?

Send note to:

snipped-for-privacy@post.htnet.hr

Tnx.

Your words once again: "There is a switch on the oil pressure sender that will cause the engine to shut down after a few seconds of seeing no oil pressure."

To which I say again. There is no such switch. Get over it.