93L: Check Engine Light --> Dies + Then Cranks Great But Won't Start

[Chobobulous]

Is the wire maybe broken?

[Twistiva]

OK, the plot thickens. I really think I found the culprit but I have 2 other questions:

Likely problem: Three times today my 93L would crank great but not start. A parts guy at my local O'Reilly's said he thought it might be a bad Engine Coolant Temperature (ECT) sensor. His girlfriend's car had a bad ECT sensor where the sensor would 'think' it was hot and turn off her engine and would not restart. If he poured water on the ECT sensor he could get her car to start immediately. So....when it wouldn't start today I also poured moderately cool water right on the ECT housing (I did not bother pulling it out of the engine head to pour water directly on the probe, I just poured it on the ECT housing) and the car started right up all 3 times. So the engine 'thinks' it is hot when it is not (there's no way a 1 1/2 minute drive to Ace Hardware would overheat the engine) but pouring water on it does in fact allow it to start? Weird. Any good ideas?

Question 1: When I put a jumper wire in the STI (Self-Test Input) code-retrieval plug (the plug is white in the picture and my jumper wire is white) and connected the alligiator clip to bare metal, then turned the key to "ON" (but not to the "Start" position) like directed in the 1st post in the thread below, I expected to see a 9-flash ECT error code on the CEL (Check Engine Light) and got.....nothing; the CEL illuminated like it's supposed to in a normal engine start sequence but the CEL did NOT flash at all. Any ideas why?

http://www.fordfestiva.com/forums/showthread.php?17417-Retrieving-Trouble-Codes-from-OBD-I-Systems

Question 2: So, when I did not get the CEL to flash I wondered if maybe it's because the code is dumped when you turn off the engine. So I started the car, connected the jumper wire to the STI pigtail plug and when I connected the aligator clip to the mare metal bolt stud the wire sparked slightly and the car immediately died. It did this 3 times. What the heck is going on?

[ATTACH=CONFIG]15820[/ATTACH]

Well, to anyone reading this thread, if you'll read the hyperlinked thread immediately below, it looks like the correct STI / self-test receptacle is a single-pin BLACK one? If so, that would answer my questions to #1 and #2 above because it appears that I may have been trying to test the Check Engine Light codes using the wrong pigtail terminal?

http://www.fordfestiva.com/forums/showthread.php?47858-CEL-Coming-on-and-Turning-Off/page5&highlight=diagnostic

[Twistiva]

It looks like I owe you a drink... sorry man.

Have you tried a wiggle test on the wire? Do you have a temperature gun you can use to test the temperature is correct? No damage anywhere else up the wire to the harness that water would maybe dribble down to and make a better connection?

Wiggle test: will do on Monday. Temperature gun: don't have one. Wiring harness: will check on Monday.

Is the wire maybe broken?

Will check on Monday.

To clarify, sometimes the engine won't start when the engine is clearly, clearly NOT hot (like after a 2 minute drive to a local hardware store first thing in the morning and the car has sat in the driveway all night)....or somehow the engine IS getting super hot and shutting the engine off when the engine should be nowhere near overheated, yet at all times if I dribble cool water on the ECT sensor the engine will immediately start.

[Chobobulous]

Is the inside of the threads maybe a little corroded? Iirc the sensor grounds through the thermostat housing.

When you dribble water over it it could possibly be giving you a better ground thus letting it fire right up? Just shooting from the hip here.

[Twistiva]

Is the inside of the threads maybe a little corroded? Iirc the sensor grounds through the thermostat housing.

When you dribble water over it it could possibly be giving you a better ground thus letting it fire right up? Just shooting from the hip here.

Chobobulous -

The threads on the ECT sensor probe looked fairly clean but I didn't check the threads down in the sensor housing/where it threads in to. Will check on Monday. Aggravating.

[Chobobulous]

Chobobulous -

The threads on the ECT sensor probe looked fairly clean but I didn't check the threads down in the sensor housing/where it threads in to. Will check on Monday. Aggravating.

Lol electrical problems normally are!

[SiliconSoul]

Just another thought, how does the ground wire going to the passenger strut tower look?

As far as your codes go, I think your not getting any flashes because everything looks right to the computer. Doesn't mean 100% the sensors are working properly, but it means they are within the "normal" readings range. That's what's making me wonder about the grounds now.

[Twistiva]

Just another thought, how does the ground wire going to the passenger strut tower look?

As far as your codes go, I think your not getting any flashes because everything looks right to the computer. Doesn't mean 100% the sensors are working properly, but it means they are within the "normal" readings range. That's what's making me wonder about the grounds now.

SiliconSoul -

The "ground wire to the passenger strut tower"? Sorry, but you'll have to explain that more clearly. I assume you're talking about the right front wheel strut? If so, what about it?

Codes: Read (my) post #32 above. I'm now not even sure I was connecting my jumper wire into the correct pigtail plug. 2 members say it's a single-hole white one. 2 other experienced members swear it's a single-hole, black spade one. I went and looked and unless I'm blind this 93L does not have ANY single-hole black spade pigtail/connectors. Am I missing something?

[Spike]

On my '90, it's a black spade single. When I went looking for it, it was pushed all the way in behind every other wire there. But it was there!

If you see that big 6-prong, and the little 2-prong, keep looking. The lonely 1-prong is right there with those, driver's side strut tower. It was white on the '93 as I remember.

[SiliconSoul]

SiliconSoul -

The "ground wire to the passenger strut tower"? Sorry, but you'll have to explain that more clearly. I assume you're talking about the right front wheel strut? If so, what about it?

Added a picture showing the ground wire. Probably not a bad idea to make sure you have good contact on both ends and confirm the wire is good with an OHM check using a multimeter. Not sure how much it would matter if it was bad as there are other grounding points, but never hurts to make sure. Especially considering the location to the temp sensor.

IMG_20140623_102651.jpg

[Twistiva]

OK....I was starting to think maybe the new Engine Coolant Temperature (ECT) sensor had actually solved it after all, since the car had only died one time after replacing it, and that occured with the nose of the car less than 2 feet from my open garage door with zero wind blowing. Not thinking that now.

Yesterday mid-afternoon: car was not driven at all until I tried to start it about 2:30PM. Cranked awesome. Would not start. Tried pouring water on the ECT sensor and this time it did not start at all. (EVERY other time, water on the ECT sensor made it crank immediately).

Yesterday evening: car started up no problems without water on the ECT sensor, drove it for about 5 minutes (i.e., it should not get excessively hot in 5 minutes), turned it off, tried to start it 45 minutes later, cranked great, would not start. Poured 1 bottle of water on the ECT sensor and the car started immediately.

This morning: car started with zero issues.

Just now (2PM): car cranks great, will not start, poured water from in the car (warm) on ECT sensor, no start. Poured cool water on ECT sensor, no start.

I previously was absolutely convinced that this problem had something to do with the ECT sensor because 4 times in one day, pouring water on the sensor allowed the car to start immediately. Not now.

(BTW, I'm not disregarding what others have said to check. Will have to work my way thru recommended fixes one at a time. Crap...)

[SiliconSoul]

Have you checked for spark on the no-starts?

[scitzz]

Have you checked for fuel on no starts?

[Twistiva]

Silicon - Buying an in-line spark checker tomorrow from O'Reilly's. However, the thread I linked to on the first page (where previous owner had it worked on) says they replaced spark plugs and spark plug wires.

Scittz - No, not yet. However, the thread I linked to on the first page (previous owner's) said they checked that the fuel pump was good. Check by pulling fuel line downstream of fuel pump off and verifiying fuel being pumped out?

When I went back tonight about midnight to tow it home, tried to start it and it started immediately and ran fine all 7 miles home. Have not seen a CEL since the first day it started giving me problems. Maddening....

[Skrapbob]

With the car running, can you torque on the VAF plug and get it to die?