I see a Temperature Switch clipped on to the Manifold in diagrams on Page 24-10-5 and 24-10-20 but I find no reference to it in print. I can not find anything at all on it in Vol. H. The EEC diagram for your truck in Vol. H shows no input from such a device for the EEC-IV or Ignition systems.

Do you have one of these on your van?

I am still not convinced that one of these items exists.

 

OK, I tracked down what this Temperature Switch clipped on to the Manifold in diagrams on Page 24-10-5 and 24-10-20 is. It is the Cooling Fan Temperature Switch if you have one, if it were bad I would think that your engine would over heat. I guess it could get hot enough to vapor lock and then when it cools down it would start again if you have one of these.

 

Since last time, the van has been running great. Until day before yesterday. Ran a key on/engine off self test, even though the check engine light never came on. After a couple of 1-1s, a single 1, I got a code of 3-4--EGR control solenoid or EGR vent solenoid signal failure. Replaced the EGR positioning sensor, the only listing that came up at the parts store. Wouldn't start after sitting for hours. Disconnected the battery after an hour of trying with starter fluid, reconnected the battery and it started. Turned it off and came back 2 hours later and it started and drove 35 miles home. Smooth, as if nothing was wrong. Stopped for gas yesterday morning and had trouble getting it started after filling up. Got it going and drove 30 miles into Atlanta. Drove from place to place Sunday, no prob until stopping for a short time at the hardware store. Could not get it started. 2 hours. Checked spark, fuel at both hoses going to manifold. It would go as if to start with ether sprayed in the throttle body. Checked the last part to be replaced, the EGR sensor, and a pin came out with the wiring plug, no big. Put the old one back in, still got a 3-4 service code. Had to get a tow home. Just replaced the sensor with a new one, cranks like it wants to start but no go. Still get a 3-4. Bad new TFI? ECA/computer? Canister purge?
BTW- I do have the switch and cooling fan, but think it unrelated to curent problem.
Regards,
RM

 

I think I would try replacing the TPS, I think that may fix your problem.

 

Will do. Thanks.

 

Ricmo:
Very common cause of this is a big vac leak. The EGR valve will not respond to the vac solenoid with a vac leak. Also if this is a Speed Density system the MAP sensor will not be able to read intake vac and mess up the mixture big time.

Look at the vac lines over the passenger side exhaust manifold. Also look at the vac reservoir "coffe can" behind the battery.

 

Just replaced the TPS. No go. Will look into the vac system more closely--Thanks.

 

All vac lines look good--no cracks! The coffee can also looks great. Replaced the EGR valve--no longer get a 3-4 code with KOEO.
Did not replace the stator pick up, as recommended by FORDFUELINJECTION.COM, when I replaced the TFI ignition module. Thinking this may be the problem. Any suggestions/diagrams out there?

 

Sorry I did not see this the first time around.
I think you have a ground problem. Two things to look for:
1. Coming off the NEG (-) post of the battery there is a small wire and after about 3 inches more or less there is a in-line connector that looks like a fuse holder and then from there is a black wire with a green stripe. Make sure this is all good or it will not run or run right.

2. The other thing is you might not have a good body ground. Try running a wire from the NEG (-) Post of your battery to a good clean body ground.

I think one of these will solve your problem.

 

Reworked all this when replacing starter in 12/05. All new cables. Re-tested continuity at wires. All good. Could it be the stator pickup if I have spark?

 

Yahoo! Replaced the stator pick up, and it started right up. Idle is a little low and acceleration is a little slow, but it starts and goes. May take a while to get the computer to sort out all of the new sensors, relays, regulator, etc. But it runs! Thanks for the help.

 

Wow, a lot of parts replaced. If by chance this dies again, considering the mileage, try disconnecting the cat. converter.

 

I'm game. What would that do? They check for it when they do emission testing.Also, most of the parts were never replaced, I think I got my money's worth. Considering I put every mile on the van.

 

Hello to all. Have been rolling along since replacing the stator pick-up, a little slow on the giddy-up and low idle--until now. Stopped to tank-up (painful in itself) this morning, and the van would not start afterwards. 20 mins. of cranking later, got going and made it to work. Am now in a No Parking zone and it will not start. Cranks like it wants to, just doesn't. Help, as always, is appreciated.

 

By the way, I get a 4-1 code on KOEO test.