90 SHO - No Codes, now No Start

[sperold]

Went from the best starting car ever, to very unreliable start situation, in about a week

The 3 or 4 key turns did not work out, if it did not start at first.

Fuel pump whirs on key turn, sometimes it starts. If it stumbles at this stage, it does not start no matter what you do. Often, in the past, if you waited a few hours it would fire up.

For years, the rad fan would run for a few seconds at key turn. Lately, if that happens, it will start first time. When it does not, it does not start.

So I checked the codes - the code reader had no information, totally dead, but I did get the 3 zeros saying it was turned on; and the paper clip did not flash the check engine light.

I am thinking this is the Engine Control Module (ECM) or whatever other name identifies it; the thing under the dash that goes through the firewall.

Is there any thing I should know before I attempt to swap it out, like any special precautions, or any absolute no-no's associated with the swap, like should I ground it manually, or whatever.

Thanks in advance, as I am always nervous about electronic boxes that do so much, but look fragile to handle.

 

[beaterbeliever]

Other than disconnecting the battery, it's fairly straightforward. There is a bolt the connects the harness to the PCM in firewall done from the engine bay, but after that it's simply remove. It can get stuck from years of sitting, but as long as you are careful, it's pretty simple. I had the same issue with my 92, a good PCM and CCRM fixed it up. There is little "guides" on the connector area surrounding the PCM that make it easy to install. Just a tip, it can be an issue getting the bolt to connect with the pcm thread, so go easy on it and ensure proper fit and don't tighten it too much, you could damage it.

Sent from my ONEPLUS A6013 using Tapatalk

 

[luigisho]

The paperclip jumper should at the very minimum give you the all clear codes. If you get nothing then most likely you are correct in a computer issue. The only thing to know up front is the bolt from the wire connector has to be unscrewed before you try and yank it from the inside of the cabin. Also if you still have the little plastic support bracket on the glove box side keep it. Some cars that had a chip removed theirs and the next owner doesn't have one. It will help keep the unit from excessive movement.

 

[BaySHO Performance]

You probably tried to read the codes correctly, but double check on how you used the paper clip:

http://wiki.wikisho.com/wiki/EEC_Self_Test_Procedure

Note that disconnecting the battery erases the stored codes. If the car won't start but doesn't have any codes, the next thing to do is to check for fuel and spark.

Check for fuel at the rails by blipping the valve on the rail.
Check for spark. One of these work great:

https://www.amazon.com/Calterm-6633...term+spark&qid=1590342971&s=automotive&sr=1-1

The fan shouldn't come on when turning on the ignition. That would, however, happen if the ECU is unplugged. Might be that the connector on the back of it near the self test port held in with a 10mm bolt is a little loose.

If all else fails, try a different ECU.

 

[blk\blk90]

Yup, I had the exact same problem on mine. Couldn't get codes, wouldn't start. It would also randomly die. Swapped in another ecu and it fired up. Some LPMs seem to prevent codes too, which sucks when trying to read them w/o it and an 80mm MAF.

 

[sperold]

Got the parts together and left it for a week. It is my foul weather winter car.

Went back and it started up, like there was never a problem. Knowing that I did absolutely nothing, i am more concerned than ever.

I am disconnecting the battery tonight to drain all the codes, and I am hoping that a fresh restart (reboot) will change things for the better.

But I do have another BCM (or ECM) and CCRM for more decisive action, in the next day or two.

When I encounter another no start situation, I am going to get a spark plug wire activity light, and I am going to check the shrader fuel valve on the intake to see which way the fail condition resides as BaySHO Performance has recommended.

 

[blk\blk90]

Got the parts together and left it for a week. It is my foul weather winter car.

Went back and it started up, like there was never a problem. Knowing that I did absolutely nothing, i am more concerned than ever.

I am disconnecting the battery tonight to drain all the codes, and I am hoping that a fresh restart (reboot) will change things for the better.

But I do have another BCM (or ECM) and CCRM for more decisive action, in the next day or two.

When I encounter another no start situation, I am going to get a spark plug wire activity light, and I am going to check the shrader fuel valve on the intake to see which way the fail condition resides as BaySHO Performance has recommended.

That's what mine did too! After sitting I went to spray starting fluid and listen to the injectors. It fired right up! A quick drive down the street and it died again. So I'd bet if you drove it, it'd die.

 

[luigisho]

Yeah. I think you should get it sorted out before it's too cold and crappy to work on next winter. I just hate wrenching in cold temps.

 

[stripSHO]

I had the exact same scenario with my wife’s old Mazda3. It either started just fine or wouldn’t start no matter what you did. Never could figure it out. Car ended up sitting for about a year or more then eventually unloaded to a family member for $500, who’s now had it for a couple years and claims to not have had a single problem with it! Only thing I can come up with is he had to replace the battery to get it out of my driveway so maybe it was the battery all along?

 

[Irish Pride]

Lower the glove box and tap on the PCM with your hand while it's running. See if you can get it to act up. Reversely, when it's in a no start situation, tap on the PCM to see if it clears up. Had a similar issue with my old 89. Would start to sputter and die. I'd pull off to the shoulder. Tap the PCM and it would be ready to go again. I did that for a couple weeks before I replaced it.

 

[sperold]

It is a starting issue only. Once it starts, it will run all day. It will start after the initial start, like at a gas station, and when you run a bunch of errands; you can shut if off in all of these situations, although it makes me sweat a little bit.

The problem reveals itself when the car had run, and has been off long enough to be almost cooled down.

It acted like it had leaking injectors, except there was never any black smoke or gas smell, and holding the pedal on the floor did not allow a start.

So far, the first start of the day goes well.

Thanks for the interest in this topic; it has me Buffalloed.

 

[Jbeck]

Lower the glove box and tap on the PCM with your hand while it's running. See if you can get it to act up. Reversely, when it's in a no start situation, tap on the PCM to see if it clears up. Had a similar issue with my old 89. Would start to sputter and die. I'd pull off to the shoulder. Tap the PCM and it would be ready to go again. I did that for a couple weeks before I replaced it.

That issue sounds like a bad ground to me, as there is nothing in the ECU to require a tapping but a tapping would jog a bad ground into a new connection until it worked loose of connection again

 

[Irish Pride]

That issue sounds like a bad ground to me, as there is nothing in the ECU to require a tapping but a tapping would jog a bad ground into a new connection until it worked loose of connection again

Don't know for sure. Swapped in an X2J and never had the issue after that. Daily drove that car for another 2 years.

 

[Jbeck]

Don't know for sure. Swapped in an X2J and never had the issue after that. Daily drove that car for another 2 years.

Yeah, you probably fixed it with the swap and just never realized what it was....I have fell victim to that before on past builds...only to go back and check the old part to realize it was still good.

 

[blk\blk90]

Don't know for sure. Swapped in an X2J and never had the issue after that. Daily drove that car for another 2 years.

Mine was an X2J that went bad which leads me too:

Yeah, you probably fixed it with the swap and just never realized what it was....I have fell victim to that before on past builds...only to go back and check the old part to realize it was still good.

I'm wondering if mine was bad. Maybe it got loose somehow or something...

 

[sperold]

Better news on my 90 SHO.

My code plug (VIP Self Test Output Connector) has a Tan / Light Green wire that goes to the ECM. It also splits off and goes to the CCRM (or IRCM) right at the test connector. The wire to the CCRM was not attached at that connector.

I am reasonably sure now that the ECM and the CCRM are both OK.

I got codes, and they are:
11 - Pass Code and things are all OK

10 - Seperation Code to get to the stored codes

29- No Speed Sensor input (mine is broke at the moment)

59- Low Speed Fuel Pump Circuit failure .

I don't know what Code 59 means, especially when the car runs now, but it does take longer to start on the key.
My uneducated guess would be the fuel pump relay in the CCRM is lazy.

Can anyone comment on the stored code 59?

 

[luigisho]

http://straighttalkautomotive.com/OBD1/ford-OBD-I.html looking for something more illuminating

Is the wire supposed to be connected? A dc'd wire is no bueno almost anywhere

Fuel pump relay or fuel pump power somewhere from computer or relay to the sending unit or pump? fpr? weird

 

[luigisho]

https://www.2carpros.com/questions/1995-ford-taurus-95-eca-wiring

https://www.fordforum.com/forum/ford-taurus-26/1993-ford-taurus-code-542-fuel-pump-eca-29977/

I don't think I've ever seen a code 59 before. New stuff!

 

[BaySHO Performance]

If a Gen 2 stalls at a light because of operator error, it will throw a 542: fuel Pump Secondary Circuit Failure. This is the same code as the Gen 1 code 59. I've never seen a 59 before, but wonder if it was caused by stalling at a light. If the car runs fine, ignore it.

 

[luigisho]

If a Gen 2 stalls at a light because of operator error, it will throw a 542: fuel Pump Secondary Circuit Failure. This is the same code as the Gen 1 code 59. I've never seen a 59 before, but wonder if it was caused by stalling at a light. If the car runs fine, ignore it.

Hard to tell since the symptom is no start and the other codes don't really illuminate that issue. Fuel pump issue is the only real cause pointed to by any of the codes present.