Engine stalls

Hi:
Even if the check eng light isn't on, there could be a code stored in the computer. Give it a shot and take it to a nationally recognized parts stores that scan cars for free. It may help.

Let me know what you find out.

Joe

Has this mechanic checked for codes? Is your check engine light on? I would look at fuel pressure first.

For a start check the exhaust gas recirculation valve for carbon-you need to open it up and investigate also the PCV valve.

Hi:
As far as the pump, without removing it, the best you can do is check for power at the fuel pump relay to see if it is there. However, based on your description, it sounds like the pump. Regardless, switch the fuel pump relay with another one in the relay box that has the same part number. See if that makes a difference.

As far as removing the pump, I never drop the tank on these vehicles. It's been a while since I did one this year, but if I recall, there are 8 bolts that hold the bed in place. I would remove them, disconnect the filler tube, disconnect any wiring that is attached to the body, and simply get a helper to remove the bed or at least move it so you have access to the tank.

Every time I would remove the tank, I would end up with broken straps, a cracked plastic fuel tank, wiring that would be damaged, broken hoses for the EVAP. Once the bed is moved, you have all the access you need.

If it starts up again after sitting a few minutes, you might suspect a plugged pickup screen inside the gas tank. It will be more likely to act up when you let up on the gas pedal to coast. You may find that by driving with a fuel pressure gauge attached that you can watch when the problem occurs.

Ask at an auto parts store that rents or borrows tools. Many hardware stores sell them as do the guys who drive the tool trucks from shop to shop each week.

There's a test port on the fuel rail on the engine that looks like a metal tire valve. Run the hose under the rear edge of the hood and prop it up under the wiper arm so you can read it while you're driving. I have one on my '88 Grand Caravan right now tied to the radio antenna. I've been searching for an extremely intermittent problem for months.

You'll see what normal is when you're driving. With multiple injectors the typical fuel pressure is around 45 to 50 psi, but it will go up when you accelerate and it should go down when you're coasting. On my van, it tends to act up when I'm pulling a large tandem axle enclosed trailer that's bigger than the van. The pressure drops as low as 20 psi but the engine will still run with no noticeable stumbling. If I let off the gas a little, the pressure pops back up to normal. At 15 psi is when it finally stalls. Most engines won't still run with the pressure that low.

Highly unlikely it's the computer. GM has a ton of trouble with engine computers, but not Chrysler.

An incorrect reading from the MAP sensor will affect fuel metering, but as long as the incorrect readings are within normal limits, it won't set a diagnostic fault code. This can cause a gradual or smooth loss of power, but not a sudden cutout like turning off the ignition switch.

Based on the mileage, you might suspect a plugged pickup sock in the gas tank. They will actually cause a problem when the largest volume of fuel is pumped which is, are you ready for this?... When you're coasting. If it runs better when you're accelerating, suspect the sock, and have the tank steam cleaned. This happened on my 1988 Grand Caravan. Ran great on the highway.

Older Dakotas had trouble with worn bushings in the distributor. The shaft would wobble causing surging from changing timing. It usually didn't cut out completely because it only affected a few cylinders, depending on which way the shaft moved within the pickup coil.

The pickup coil can develop breaks in the wires from heat. Your timing is computer-controlled, but on older engines, the pickup coils were mounted on a movable plate. As the plate moved to change timing, the pickup coils would flex, leading to broken wires. When it moved just right, the engine would cut out instantly.

Try a MAP sensor first, and the engine computer last.

Caradiodoc

Hi:
First, the cheapest thing to check for are vacuum leaks. If you find none, have the computer scanned for trouble codes. Most nationally recognized parts stores will do it for free. To me it sounds like a throttle position sensor (TPS), but I can't tell without the scan.

Let me know what you find.

Joe