Chrysler Repair: Problem Solved ! 94 3.3L no start, crank sensor, dodge caravan

Question
Hello Roland,
Just to let you and your readers know. I recently sent a question to you about my 94 Dodge caravan with a no start problem. I did some checking of sensors as you suggested.I found nothing out of specs. The most obvious was the crank sensor. With fuel and spark,ok. I had no codes for this sensor.Replaced the sensor and everything ok!

As always, THANKS for help ! It is much appreciated !

GCM

Answer
You are welcome. It is good that you delved further into that sensor. I can't understand though, if you had spark then why would changing the crank sensor solved the problem? Serendipity, I guess. Thanks for letting me know how this one was resolved.
I am attaching the history of the problem for others to reference.
Roland

Engine Dies: '94 3.3L
Question:  QUESTION: Hello Roland,
If you remember ,last year you helped me with a 95 Ply. Neon. So far everything works good !
I have a problem with a 94 dodge Caravan, 3.3 engine vin-R.
I pulled into a driveway and the engine died. Crank and started about 3 times. Than no start. Got towed home. I scan tested. No codes. I have spark and fuel pressure. After a while in the driveway, it started, ran for a while and died again.About everything has been replaced in the past.PCM, alt, fuel pump and all sensors. Does this vehicle use a crank sensor ?Nothing listed on my scan tool at all.
Also, on the scan tool I see a code 151 ? In the diagagnostic mode. I have not found any such code. Also, key on off test gives code 55 only. Seems as if all relays are working with scan diagnostics.Right now I can idle engine for some time and the engine dies. It will stumble and restart again.I thought I found it by wiggling the wire harness as it will die at times.
Any ideas ?

Thank You,
GCM

ANSWER: Hi Gary,
Yes, the 3.3L has both a cam and a crank sensor, but if you are getting spark and no 11 or 54 fault code then those sensors are not the problem. I wonder if it might be a mixure problem due to the exhaust gas recirculation valve being stuck ajar? It is located along a small pipe that branches off of the exhaust manivold on the firewall-side manifold and runs around to the vicinity of the air intake throttle body. The body of the valve is bolted into this pipe, and it has a round vacuum operated solenoid on the top of it. Separating the two parts is a flange inside of which you will see the valve stem that has a slot in it into which you can insert the tip of a screwdriver and move the stem back and forth. You will feel spring-action trying to resist the motion and which closes the valve. Check that the valve stem moves freely and that the spring closes it to a dead stop. If it seems sticky then spray some WD-40 on the stem where it inters the body and move the stem some more to free up its action. Then see if the van will start and run. That is one of the main components that is not monitored well by the self-diagnostic capability of the engine.
Roland

---------- FOLLOW-UP ----------

QUESTION: Hello,
Only code is a 55 with key on off test. Good thought, but egr is working fine. I just had it running for about 10 minutes then it dies. It may or may not restart. At times if I pull on the wire harness, engine dies.Seems if that is the problem. Then another time it does not make any difference.I see the crank sensor at the top of the trans. I just wonder if maybe that still could be the problem.
This was the main culprit on the 95 dodge neon. It did not have an engine code. After replacing the sensor it took care of the problem.Are the crank and cam sensor the same sensor? I do not see any other sensors at the front of the engine.

Thanks again,
GCM
 
Answer:  The cam sensor is mounted on the front of the timing case cover on the right side and 'looks' at cut outs in the cam sprocket. You can test each sensor by measuring the voltage between the signal wire and the ground wire while you turn the engine by hand via the crank bolt and with the ignition in the 'on' position. It should oscillate between 5 and 0.3V several times per revolution of the engine. The cam wires to test are tan/yellow and black/light blue while for the crank sensors the wires are gray/black and black/light blue.
If flexing the harness kills the engine then there is an intermittent open circuit.
Roland