ENGINE SHUTS OFF AFTER RUNNING FOR SOME TIME

Thank you very much for your response.

In pursuance of your advice, I have purchased a Fuel Pressure Tester.

I am unable to find a test port on the vehicle in question to connect the tester to. Kindly let me know where to connect the tester.

I await your response.

Regards.

Kabeer Sayeed

Thank you very much for your response.

Following your reply, I studied the descriptions and diagrams in the original Daimler Chrysler manual for the Dodge Grand Caravan 2002, 3.3 litre, V6. There was no indication of any Fuel Pressure Test Port. I wonder why.

I then looked at the engine from the driver's side where the ignition coil is located. I could see no test port. Perhaps it is hidden behind the Power Steering Fluid Reservoir which is just above the ignition coil. Do you think removing the reservoir may expose the test port?

I also looked at the passenger side of the engine where the air intake is but could not see any test port. I wonder if it is hidden inside the Upper Intake Manifold. Will removing the manifold be necessary in order to expose the test port?

Regarding the Auto Shut Down (ASD) relay which, according to the Manual, is located in the Integrated Power Module (IPM), will this cause the engine to shut down while it is running? As I have mentioned in an earlier message, the engine idles for about 15 minutes and then stops. If it is started after about 15 minutes, it runs for another 15 minutes and so on. These times are very approximate and vary. Some times, striking the bottom of the fuel tank after the engine shuts down causes it to idle longer (up to 90 minutes). Could the ASD relay be causing these varying behaviours?

Incidentally, the VIN for this vehicle is 2B4GP44R32R601774. Perhaps it might be of help in resolving the difference between the original manual, which says absolutely nothing about the test port, and the opinion of experts such as yourself regarding the Fuel Test Port.

I look forward to your response.

Regards.

Kabeer Sayeed

Thanks for your responses (Catafina & Ken).

I found something that looked like a "Fuel Rail Test Port". It seemed to be on the fuel rail as suggested by Catafina. It was close to the ignition coil and just behind and under the power steering reservoir. I had to remove the power steering reservoir and it was behind it. It was on the fuel rail which runs in the middle of the upper intake manifold.

It is rather strange that the designers of the vehicle made it so very difficult to obtain access to a simple test port! The design was as bad as the design of the fuel tank and filter where I had to remove the tank to replace the fuel filter which could have been, quite easily, kept in the engine compartment as was the case with other vehicles that I have owned.

However, the "Fuel Rail Test Port" has a peculiar cap on top of it. When I tried to unscrew this cap, it just kept on rotating and did not come off. On examination of the cap, it appeared to be secured to the port in a rather odd way which was quite unlike the usual threaded caps on Schrader valves. It had metal tabs below it which seemed to secure it to the test port.

Before I try to remove it using some other method and perhaps cause damage to the cap and the port, I would like your expert opinion on the best way to get it off.

I look forward to your response.

Regards.

Kabeer Sayeed

The cap does not come off by unscrewing it because it is not a threaded cap as I have mentioned earlier. I had to open the tabs to remove the cap. After removing it, I found that there was no way to screw on a pressure gauge to it because there was no threaded port. I could see the fuel inside the fuel rail. I replaced the cap, and secured it using a hose clamp and tested it to make sure that the fuel did not leak.

It looks as if there is no fuel pressure test post on the vehicle. I suspect that one has to use Chrysler's DRBIII scan tool to measure the pressure on the vehicle in question. This tool costs several thousand dollars. The only other way of checking the fuel pressure may be to insert a test port into the fuel line.

What do you think? I would like your expert opinion and advice on this. I await your response.

Regards.

Kabeer Sayeed

Thank you for your response.

I have done the following in order to resolve this problem:

1. Installed a fuel pressure and flow test port in the steel fuel line immediately after the fuel filter with a steel Schrader Valve to connect the fuel pressure test gauge.

2. I have then used an Innova fuel pressure test gauge to test the fuel pressure. The following are the results of the test for the vehicle in question:

2.1. Fuel Pressure with Engine Running: 425.0 kPa (65.0 psi approximately).

2.2. Fuel Pressure with Engine Off and Ignition On: Same as above.

2.3. Fuel Pressure with Ignition Off: 400.0 kPa (58.0 psi approximately).

2.4. Fuel Flow Rate as measured through the discharge port of the Innova fuel pressure test gauge with Engine Off and Ignition On: 0.250 litres per minute.

2.5. NOTE:

2.5.1. The fuel pump continues to run with the Engine Off and the Ignition On but it stops for less than a second and then runs again for about 5 seconds and repeats this cycle over and over again as long as the ignition is on.

2.5.2. The results of the pressure test indicate that the pressure readings are within the specifications as contained in the original Daimler Chrysler manual which are as follows: 400.0 + or - 34.0 kPa (58.0 psi + or - 7.0 psi).

2.5.3. There is no specification in the manual for the fuel flow rate.

3. I then tested the ASD (Auto Shut Down Relay) by switching it with another identical relay. This did not solve the problem of the engine shutting down after running for random intervals of time. These times vary between 5 minutes and 90 minutes or more with the engine idling.

Some history might help. I have never had this problem with this vehicle and the vehicle has been running reliably for 14 years with only routine maintenance. It has close to 400 000 km on it. This problem started after I took the vehicle for emission test repairs to a very large and leading repair establishment for carrying out emission system repairs required by the Department of Transportation. Just before I took it for the repairs, I had driven the vehicle from one city to another for a distance of 650 km WITHOUT ANY PROBLEM.

I now await your expert opinion on the causes for the random shutting down of the engine.

Sincerely,

Kabeer Sayeed