I am brand new to the forum so if I have placed this in the wrong section please direct me as to where I need to go. I repair ambulances and have one that just died and had to be towed. Ran my scanner on it and came up with nothing other than the back pressure code. Changed the fuel filter and also the electric fuel pump. Ran an injector buzz tes and came back clear. Seems to cycle the glow plugs and develops oil pressure while cranking. Shot a little starter fluid into the intake and it will catch but then die immediately. The crew that brought it in had said that it would die at time before this when they would sit at idle for a while and then take off. Also would die when decelerating. I have replcaed the CPS as well with no change.

Any ideas? I have checked power to the injector pump yet and all fuses and relays appear to be intact.

Thanks,
Alan

 

It sounds like that the connector to the computer behind the left fender is either loose or the contact are dirty. Also, when they build ambulances, the mfg really screws around with the wiring. They may have pinched the harness. Trace the harness around the left fender well from the front to the firewall. I bet you may find a crush somewhere.

 

What year is this ambulance in question?

 

This is a 1998 E350. The batteries have been relocated to a storage box on the left side of the van.

 

when the CPS was changed did you make sure that the contacts were clean and that it set tightly in place?

 

I agree that this seems just like a CPS that has gone out. I'm second guessing putting the new one in, but you've got me second guessing it. I will check it again Monday morning. I have pulled the comtrol module out and a friend is going to have it checked for me. When I went to pull the control module out I pulled the recovery tank and there is a large harness right behind it were clearly rubbing against the tank. I have seperated the wires and and looked them over very carefully and they are intatc, but at least I have found another problem before it became one. Any other ideas. I spoke with one of the crews who told me that the truck ran poorly and stalled in the rain.

????

 

that was exactly my precise problem. only bad running when it was raining....bad CPS. replaced with a cheapie brand new one from ebay and all is awesome.

 

Now that I think about it, that was when my CPS started acting up. Either after a rain or when the humidity was quite high.

 

The one that I repalced it with was one that I had on the shelf. About six months ago we had a truck that was killing and giving CPS symptoms. Pulled and replaced the CPS and there was no change. I will get a new one tomorrow morning and give it a try along with checking to make sure the connections are clean and secure. Need the truck, can't wait to get one shipped in.

Thanks and I will let you know what I find out.
Alan

 

Just go to Internation instead of Ford. The are a lot cheaper.

 

I'll do that first thing tomorrow and advise what happens.

Thanks for your help.
Alan

 

Make sure that you take the block serial number with you so they can pull the right sensor. IH just changed them. Seems they got a bad batch of them.

 

Well, I installed the new CPS and had no chnage to the problem. No start. Spins but no catch. A friend told me that I may want to check the injector pressure regulator.

Thoughts???

 

first of all, check all of the fuses you can find. some guy posted a question here a few days ago, i advised him to spend $120+ on a new throttle pedal assy, and after a change, still the same problem. a member came along and said to change the fuses. one new fuse later, no problems.

also, have you checked oil and coolant level?

 

I have checked every fuse and relay. All seem to be intact. The vehicle had popped a fuse before and we found it and replaced the fuse and it started right up. The fuse in question activated and powered the electric fuel pump. I replaced the pump as it was original but still no luck.