Mysterious intermittant no-start, '94 Navajo

[GaryWR]

I've had this '94 Navajo since 2000. Starting around a year ago, at intervals of once every 1-2 months, the engine wouldn't start. Starter turns engine over speedily, but won't catch. Sometimes, after 10-20 tries, it will start and then no problem again for a week or a month. Twice, had it towed to my local mechanic, but on arrival at the garage, started right up, no problem. Replaced ignition wires, plugs, fuel pump relay, fuel pump, but a month later -- same again. Problem is occurring more often now, every few days. Tested for spark during an occurence a week ago (paper clip in coil pack to ingnition wire) -- no spark! Then the engine started with one wire off (plenty of sparking then!) and no problem with starting for another day or two. Then again, grind ... grind, no start. Tried the paper clip in the plug-end of an ignition wire this time, and again no spark, and then again engine started up with the wire off with sparking from the paper clip aplenty. I just took it to the mechanic again, but it started right up repeatedly and ran nicely. I could leave the Navajo with the mechanic and hope it malfunctions for him shortly, but if it doesn't my rental car bill will hurt.
Anyone with a definitive idea out there as to best action to take?

 

[wolfnutts]

[/U]http://www.explorerforum.com/forums/showthread.php?p=1330443[/url] hello try an read threw this post to see if it will help ya

 

[tdavis]

I'd check the fusible link, the grounds, and the fuses.

When my navajo had starting problems, it ended up being one of the battery cables had a open in them - in certain conditions, it would start and run fine, and then BOOM, nothing.

 

[TennTechMan]

I recently had trouble with my ignition switch. I had a problem very similar to yours. What was happening was that the contacts were wore in the ignition switch so that after holding the key in the start position it would seem to fire, but when I let go for the key to spring to the on position, it was coming off the contacts. I figured it out one day by accident. The next time it gives problems, if it starts to fire, let the tumbler go to the on position but continue to hold some pressure towards the start position.

This sounds kind of confusing, but I don't know of a better way to describe it.

 

[GaryWR]

Maybe a sticky power relay to the EEC

Thanks for the encouragement. It looks from the circuit diagram in the Haynes book, that the symptoms described in this thread could be caused by a intermittantly non-closing of the EEC power relay, there in the engine compartment fuse/relay box. I think I'm going to get a new one and have it handy, but not put it in until I get another no-start event and then check the voltage on the down side of this relay. Now...to find the best place in the wiring to do this and be ready. Most certainly it will be nighttime, windy and raining.