Hey Guys,

I have been having an intermittent no start problem with my '94 Ranger 4.0L. Last week I pulled into a store, shut the truck off, and when I returned to start it again, it wouldn't start. It would just turn over, but no start. Eventually it did. Until today, the truck would start right up like nothing was ever wrong. The check engine light was on (OK, has been on for like 3 months now-I knew what the codes were) so I scanned it today.

117 ECT sensor- I have tried to fix this issue for almost a year now, like visiting inlaws it never leaves!

337 EGR sensor-I don't know what the deal is here, I have to replace the DPFE sensor at least every 6 months! New cat a year ago and have cleaned the Egr valve several times.

212 SPOUT connector-Now here is the code I believe that is giving me trouble with starting. I did some searching on the net but did quite understand it all. Anyone here ever have this issue before? Where should I start with this code? After running, it doesn't cause any driveability problems and subsequent restarts are fine.

Thanks in advice for your help!

 

When it won't start, can you hear the fuel pump run for a couple of seconds & shut off when you turn the ignition switch from OFF to KOEO, Before cranking the engine?????

If not, then give the under hood fuel pump power relay a good thump & see it it'll wake up & run the fuel pump, or just swap the fuel pump power relay for the A/C relay & see how it goes.

Let us know what you find.

 

how's the coolant? Has it been replaced recently?

It might be a heat soak no start issue.

 

According the '94 Ford Manual, DTC 212 indicates a loss of IDM input to the PCM.

Possible causes:

-- Open circuit.

-- Shorted circuit.

-- Damaged ICM.

-- Damaged PCM.

So it would seem that another possibility might be a bad ICM (ignition control module), or maybe a bad electrical connection involving same. The ICM is responsible for generating the Ignition Diagnostic Monitor (IDM) signal and sending it to the PCM (which uses it to indicate a coil firing failure and also to provide a tach output signal). Have you experienced any tach issues lately?

As far as I know, the '94 4.0L Ranger has the "stand alone'" type of ICM, which is located up front, at the right-hand front corner of engine compartment, mounted on the upper radiator support.

 

Thanks everyone for your replies.

Pawpaw, I can hear the fuel pump switching on with the key. Fuel pump and ECM relays were replaced early last winter when trouble showed up there (truck wouldn't stay running in cold weather due to faulty relays).

Coolant was replaced last summer as a last ditch effort to solve the 117 code. I was getting a bit of galvanic charge in the coolant and thought fresh coolant might relieve the code. Oh well.

Rockledge, I can't say for sure when this code showed up, (the CEL was on for the 117 code for a quite awhile), but about one to two months ago the tach would not work when I started the truck and the CEL would come on (the CEL for code 117 is intermittent, not solidly on). If I shut the truck off and then did a restart, the CEL would be off and the tach would be working. This was a random occurrence, and once in awhile the tach would abnormally bounce around, but there was never any issues with starting.

However, the tach has been working since that time. The truck has 162K on it and alot of "stuff" on there is original, i.e. coil pack, IAC, etc. etc.

Where would be the best place to start diagnosing the ICM and would a malfunctioning tach be indicative of anything?

Thanks for your help guys

 

OK, good feedback, so we can likely set the power relays aside.

I like Rockledges post about the ICM, as it's used to drive the Tach & you say you've had intermttent problems with the Tach.

Seeing as how the 212 trouble code says the Spout connector or wiring is on the suspect list for erratic behavior & it's easy to check, maybe first pull the SPOUT connector & check it for any damage, or loosensee of fit, or any corrosion on it's pins or sockets, or damage to it's wiring, as poor or no contact there can cause the timing to jump around.

If that checks ok, then look to the ICM wiring for damage or loose, or corroded electrical connections, or the ICM itself, which can be bench tested & if the problem usually happens when it's warm, use a hairdryer to warm it up during the bench test.

On the code 117, ECT low, or grounded, so check the wiring to the ECT. Having this input to the computer messed up will confuse the computer about the engines true operating temp & can mess with fuel trim, driveability, mpg & the cat converter operating temp.

On the code 337, EGR feedback signal was/is high-EVR. Are you hearing any spark knock/ping????

More thoughts for consideration, let us know what you find.

 

The IDM signal is used by the PCM to drive the tach. So an ignition module that generates a bad IDM signal could also be the source of a flaky tach.

Regarding the ICM diagnosis, what I've posted above is what the book says. To test the integrity of the IDM circuit, look for the Tan/Yellow stripe wire leading from the ICM to the PCM (I believe it's pin #2 at the ICM and pin # 4 at the PCM.) Knowing each side, you can test the circuit for short to ground or open. If the circuit checks out OK, that leaves either a bad ICM or bad PCM. It's been proven that ICMs fail much more often than PCMs do.

 

Pawpaw, thanks for your response. The 117 code has been with me for so long it is like family now. I have tried endlessly to diagnose it properly. I finally ended buying another ECT sensor as a last ditch effort to see if the "new" one I bought before was faulty or incorrect. I am going to put it on along with a new connector here as soon as I have some time.

Here is the link to trouble I posted about last year regarding this code:

https://www.ford-trucks.com/forums/7...ode-117-a.html

What stumped me the most at that point, and since, is that the CEL would only come on intermittently, like with the engine under load (say driving up a mountain or hard acceleration). If there is an issue that sets the CEL, shouldn't the CEL stay on till the issue is resolved?

As for the 337 code, I haven't noticed any spark knock or ping. The first time I got that code, I replaced the DPFE sensor and had an issue with loss of power. It wasn't too longer after that I realized the cat was bad on the truck and ruined the new DPFE sensor (too much back pressure). So I got another one and that cleared the code up for about 6-8 months and then it came back. At this point I cleaned the EGR valve, IAC valve, and the upper intake plenum. Still, every 6-8 months the DPFE goes south (I can't seem to find Motorcraft brand for this and even a good NAPA brand did not last any longer).

Rocklegde/Pawpaw, I will check out the ICM wiring probably later today after work. I briefly checked the SPOUT connector last night. The connection was defintely tight and the pins may had some corrosion or rust inhibitor on them, it was kind of dark outside.

I do remember there were a few times where the tach just quit working all together as I was driving down the road. It would just fall to 0 as if it had lost its signal. Then the next time I drove it, the tach worked fine, so the ICM or its wiring is highly suspect as you guys have pointed out.

Thanks guys for all your help. I'll post back after I do some testing and let you know what I find.

 

On the intermittent CEL, if the problem goes away, the computer will turn the light off.

As an example, last year I had a lazy O2 sensor on my 94 Taurus, that would turn the CEL on & off as I'd climb a hill.
They were OEM O2 sensors, with over 100K miles on them, so it was past time for new ones & that fixed the CEL.

So scan the computer again & post All the trouble code numbers you have.

On the DPFE sensor, make sure the vacuum hoses to it are open & not clogged up.

On the ECT, go to the link I posted last fall & check the warm & cold resistance numbers of the sensor you have in there now, with the values in the link.

You said your problems went away after you cleaned & tightened the firewall computer connector, so maybe it needs another cleaning, along with the SPOUT connector & use CRC electrical contact cleaner to do it, NOT brake fluid cleaner, as it's solvents may not be kind to the connectors plastic & rubber parts.

Keep us posted.

 

Thanks Pawpaw,

I didn't get a chance to work on the truck last night as I had hoped. I did check the Ford Fuel Imnjection site and although I don't recall the values I got, I remember that they were within spec. After all that work the problem did go away for about a week, then came back. That was when I basically gave up on the whole thing.

I am going to recheck the values and do some more cleaning of the electrical connectors with the proper cleaning agent.

The codes posted earlier were all the codes that were present at the time of scanning. Once I can get these codes cleared up, I am going to scan with KOER to see if any are present there.

I'll post back to this thread, it may take a few days, when I have done some more testing and get some results.

Thanks again.