Hard starting 94 exploder XLT

[Oldman]

Hope someone can figuire this one out! Purchased a nice 94 XLT to replace a 92 Sport and I can not figuire out the hard starting problem. The previous owner sold this exploder because he had taken to a garage and they could not figuire it out and he did not want to put any more money in it. The problem; on a cold start it will crank but only fire for a split second then die, after about 10 times doing this it may fire but run bad for about 2 minutes till it is warmed up then it is fine unless it sets for more than 2 hours. The other day after repleatedly trying for 15 times, held the pedal to the floor and turned the key and it fired right off. The check engine light is not on, but a code reader will pull a 211 code which is a Profile Ingnition Pickup fault. So far this is what has been done; replaced the crank postion sensor, replaced the throttle postion sensor, checked the EGR valve, replaced the EDIS Module, replaced the Ilde Air Control, checked fuel pressures and replaced the fuel pressure regulator, checked continuity of the PIP circuit between the crank sensor and the EDIS and the EDIS and the main ECM. The garage that the previuos owner had taken it to replaced the spark plugs and checked and repaired all vaccuum conections. Replaced the coil pack. All the replacement parts are used and come from exploders that run. We just swapped them out and see how my 94's parts worked in a good vehicle. This 94 has 176K on it and all the ignition parts have been original till I started swapping them out. OK, has anybody out there been down this road before? I am at the end of my rope and do not know where to look next. One thought I had was to replace the main ECM, but do not want to use the one from my 92 because the 94 has a different EGR system and may not be compatible with it. I just hope someone reads this and has an answer to my problem. This is a clean 94 that has been taken care of and not abused and would like to hang on to it for a while.
Hope Someone Can Help, Thanks, Oldman

 

[Verno]

Have you ran the KOEO test?
My thoughts are #1 verify spark to plugs
#2 verify power to injectors
#3 verify fuel to injectors
this should narrow it down. (ie if no spark, all the fuel in the world won't help; likewse all the spark isn't helping if no fuel pressure.)

 

[ranger7ltr]

Look at the ECT sensor...

The symptoms you have sound like a defective ECT sensor...Assuming you have spark...IF you try a starting fluid blast when the engine is cold and it starts then you are not getting enough fuel when the engine is cold...

And for the PIP problem I bet you have an intermittent camshaft position sensor....

 

[Oldman]

To Vero and ranger7ltr

Yes, I ran the KOEO test and that is where I am getting the 211 PIP fault. I switched the crank sensor with the one off my 92 and there was no change. That is when I did a continuity check on the wiring from the crank sensor to the EDIS and then the EDIS to the PCM. I ran the fuel pressure test and had 39 psi at the rail, KOEO, and 30 psi with the engine running, (when I finally got it started). When it tries to start it sounds as if it is flooding. The last few times I held the pedal to the floor to get it going. Read if you hold the pedal to the the floor during a cold start the PCM will shut off fuel to the injectors and it seems to work. Have not checked the ECT yet and got the specs from a thread last night. Will try that tonight. Funny, I was talking with a neighbor last night that has a Toyota Tacoma that is having the exact same problem only his starts faster than mine. The mechanic that looked at it said the ECT is telling the PCM that the engine is 175 deg when it was never started. I am glad that rice burners have issues too. But his rice burner is starving for fuel, but my exploder is flooding? Will check the ECT and check the spark also. Any other information that you know of, I really appreciate it. Thanks for the feedback. Oldman

 

[MrShorty]

If you clear CM, then try to start it, does the CM 211 come right back immediately?

One common cause of "flooding" on these is a bad FPR. I know you changed it once, but I would pull the vacuum line off of the FPR after the next attempt to start and see if there is gas in the vacuum line.

ECT isn't difficult to check, it's a simple thermistor that can easily be checked with an ohmmeter.

 

[Oldman]

Code 211 comes right back

MrShorty,

I cleared the computer by having the battery cable off for about an hour while checking PIP wires for continuity. Checked the codes before I attempted to start it and had one for no KAM, (I believe it was 512), because the vehicle had not been run. Tried to start it twice, and it would not, and checked the KOEO codes and again the 211 was there. I will go home tonight and hook up the fuel pressure gauge first, then check the ECT sensor, and then KOEO. Will take pressure readings then attempt to start. We will see what happens! The engine has not fired since Saturday afternoon and has only been cranked about five times since then and it did not start.

 

[MrShorty]

Tried to start it twice, and it would not, and checked the KOEO codes and again the 211 was there.

That suggests there's a real problem with the PIP signal, and that's where I would expect your problem is. You've replaced the CKP and checked the wiring. How about the ICM?

 

[Oldman]

If you mean the EDIS, yes, that has been swapped out with one from a running exploder. About the only thing I have not replaced, is the main ECM. The MAF has been replaced, the manifold air pressure sensor has been cleaned, (forget what it is called-getting burnt out on acronyms), TPS replaced, ICS replaced twice, plugs, coil pack. Last time checked fuel pressure at 39 psi KOEO, 30 psi running. Added five gallons of fresh fuel. Checked continuity on the PIP circuit. What am I missing?
That reminds me to ask this question about fuel pressure gauges. After hooking them up, they DO have to be bled of air before you get a real value? I bought mine brand new from AutoZone and the first time I used it pressure readings were low, dropping off fast, till I bled the air out it, then it stayed constant and got the same readings after checking it multiple times and letting it set for a while before checking pressures again. The directions for it said nothing about bleeding the air out, just bleeding the gas out after you are finished.

Thanks, Oldman

 

[MrShorty]

Depends on what you mean by EDIS. When someone says "EDIS" I usually think of the coil pack passenger rear of the engine with all the spark plug wires.

When I use the term ICM, I'm referring to the ignition control module. On my '92, it is located passenger front of the engine bay, next to the radiator, in front of the battery -- I'm pretty sure it's in the same place on your '94. ICM receives the signal from the CKP, processes it to generate PIP/TACH and sends it on to the PCM.

Which of these two are you referring to by EDIS?

 

[Oldman]

Edis - icm

What I was referring to is what you call the ICM. All manuals that I have read call it the EDIS. Explorers use EDIS6 for the six cyl engine. It is in front of the battery and feeds the PIP signal to the PCM in the passenger footwell and the PCM sends the SAW signal back to the EDIS to fire the plugs thru the coil pack.
Last night I checked resistance on the coolant sensor, 47.75 @ 60 deg in garage-within range. Checked air charge sensor, 45.68 @ 60 deg in garage-within range. Checked spark with tester-jumped 1/2 in and fired continuously. Checked fuel pressure-39 psi, KOEO, and then dropped to 36 psi after 20 minutes with key off. Cranked it over 5 times for testing and it never started.
My next test tonight will be checking for voltage at injectors. I hate removing the connectors from the injectors because they have a habit of breaking but this must be done. Next will be shooting either in the intake.
If that checks OK then I am going to contact a local Catholic church and have the preist come out and do his thing on it. This vehicle may have a demon in it.
Thanks for your help, Oldman

 

[Oldman]

Fpr

MrShorty

Forgot to mention that pulled the vacuum line off the regulator after trying to start it and there was no gas present.

 

[MrShorty]

Do you have spark at the spark plugs?

Do you have access to a good manual? I just quickly looked through the circuit test for a CM 211, and it basically points you to the generic "no start" circuit test which describes the basic tests for the PIP circuit, and how to see if the PIP signal is getting to the PCM (basically put a voltmeter on the PIP circuit and see if you have 3-7 volts.

 

[Oldman]

MrShorty,

Did not get a chance to work on it last night because of other issues. All I have is a Haynes Manual which tells you nothing and says to take it to your friendly smiling Ford dealer for working on EEC IV ignition issues. I would take it to Ford but I know the bill would be more than the value of the vehicle and they may still not fix it.
Did they say to check for voltage at the PCM? If I have time tonight or tomorrow I will check it and get back to you.
Thanks

 

[MrShorty]

Yeah, your typical DIY manual doesn't have full pinpoint tests, probably because there's no way they could include that much information in a usable sized DIY manual.

Most libraries carry professional series repair manuals (you'll be looking for the engine performance, diagnostics, and troubleshooting or similar volume). Some even provide access to online repair manuals.

The manuals say to use a breakout box for testing these things. Breakout boxes tend to be expensive, so I backprobe the connector instead. Just means you have to be careful not to damage anything.

 

[Oldman]

MrShorty,

Last night's episode included checking spark with the plug removed-it had spark. Checked voltage at the injector-was anywhere from 3.5 to 5 volts while cranking. I believe the voltmeter can not keep up with the pulses to give the 12 volts I was looking for. Sprayed either and it still would not fire. I cranked it at least 10 times running these test plus a few more to see if it would start, which it did not. Pulled out a plug and it was covered in gas. Plan on going to the boneyard sometime this weekend and get a PCM. Will also get a fresh set of plugs. It had new Motorcraft platinums in it and I am going back to the standard Motorcraft plugs. Will also check the the voltage at the PCM for the PIP circuit. Will keep you posted.
Thanks

 

[MrShorty]

Checked voltage at the injector-was anywhere from 3.5 to 5 volts while cranking.

Which side of the injector was that on? What do you read while not cranking? The injectors are supposed to have a steady +12 V power supply and the computer acts as a ground side switch. Just want to make sure this looks right.

You're correct in that a DVOM is not the best tool for testing injectors. I've used an oscilloscope to see the injector pulses, or you can buy a "noid" light for testing injectors.

 

[MrShorty]

Checked voltage at the injector-was anywhere from 3.5 to 5 volts while cranking.

Which side of the injector was that on? What do you read while not cranking? The injectors are supposed to have a steady +12 V power supply and the computer acts as a ground side switch. Just want to make sure this looks right.

You're correct in that a DVOM is not the best tool for testing injectors. I've used an oscilloscope to see the injector pulses, or you can buy a "noid" light for testing injectors. However, where the plugs are wet, it would appear that the injectors are firing as they should.

 

[Oldman]

More info

MrShorty,

I had 12V with KOEO for the injectors. Checked the PCM yesterday and here are my findings:
Had 12v coming to PCM from PIP- green/orange wire. The SAW circuit, PINK wire, had no voltage KOEO and read around .2 to .5 while cranking. The information that I have said it should be 3.5 volts returning to the EDIS. Planning on getting a PCM from the boneyard today and see what happens.

 

[Oldman]

It's running !!!!!!!!!!

MrShorty,

Got a PCM from the boneyard today and put it in and she fired right off and did not miss a beat. Ran the code reader and no codes are present. I am so happy this issue is done with. I kind of figuired it could be the PCM when I went to the boneyard and the first 94 I came to had a remanufactured PCM from Ford. That was not a good sign that these computers last forever. Well, anyway I learned a lot and I hope you have learned something also. If anyone has a hard starting problem, we can reference them to this thread for all the information they need.
Thanks again for all your help and it has been good chatting and sharing information with you, Oldman