Rain = no start

[LafaMJ]

i have a 89' MJ with a 4.0. Today i got in it and it started right up and i went to my friiends house to work on his Toy. 5 hours later and some rain also, i go out to leave and it doesnt start. Turns over and the batt. volt is fine. It also is gietting fuel. no idea whats up. So we ended up bump starting it then the idle went crazy it was around 2500 and 3000!! i dont know what it is up. It happed in San Fran one a rainy night at SFFD Station 7. Same deal but i had to get it towed back to my house and once it got of the truck it started right up... any ideas??
Thanks,
Chad

 

[mack]

at first it sounds like a dist cap, pull the cap and check for a crack or any water, that would give you a no start, as for the high idle, that could be a TPS.

 

[RichP]

Second on the cap, crack, warm engine, condenses moist air, wet dist. First one I ever had drove me nuts for a few weeks....66 mustang 6cyl...

 

[langer1]

So we ended up bump starting it then the idle went crazy it was around 2500 and 3000!! i dont know what it is up.

ASD relay IAC did not reset when you turned it off, also called the PowerLatch relay.

 

[stewie]

just pulling something out of my butt, but is your TPS getting wet? i know when i sprayed out my engine bay and forgot to cover it, mine was very difficult to start then had a hard time staying running. once dry, its fine.

 

[carnuck]

Bulkhead connector getting wet? (87/88 have another above the brake booster) That could mess with the signal from the sensors.

 

[Sand-Dog]

I would also bet on a small crack in the dist cap. That will be the cheapest part to try first. If the plug wires have over 100,000 miles on them, you may want to replace 'em at the same time...and the dist. rotor.

 

[langer1]

I doubt the Rain had anything to do with it.

 

[TickDontPick]

My '89 XJ does this on occasion also. Whenever it doesn't start or idles high, I lightly hit the IAC with a hammer, and it goes back to normal.

Chances are your IAC valve is sticking and will need to be replaced. I havn't replaced mine since the hammer trick works, but I doubt that will work forever.

 

[langer1]

So we ended up bump starting it then the idle went crazy it was around 2500 and 3000!! i dont know what it is up

Here's what happens.
Every time you turn your key off, your computer stays on for three seconds to set the IAC back to 0 you should hear a 3 second buzz/hum.
When you turn your key on to start the computer advances the IAC the amount needed based on tempature.
As the engine warms up the IAC is retracted as needed.
The computer always counts from 0 so if the IAC is not reset everything is off.

 

[Tweeternpi]

I am having close to the same problem. But I do not have the Idle problem. If it is wet out I will not start. Replace plugs, wires, Cap, Rotor, and coil. It is getting gas because I can smell it after I try to start it. All it does if Flood it. After it drys out it will start. Any ideas What to look at next?

 

[jdelamater]

I am having close to the same problem. But I do not have the Idle problem. If it is wet out I will not start. Replace plugs, wires, Cap, Rotor, and coil. It is getting gas because I can smell it after I try to start it. All it does if Flood it. After it drys out it will start. Any ideas What to look at next?

I'm resurrecting a long dead thread b/c I have the same problem. Any moisture, not just rain - even a morning dew! - makes it supers hard to start. 10 minutes of sporadic cranking normally gets it fired up but it's SO annoying. I have new plugs, rotor and wires. Any ideas are greatly appreciated. If this keeps up, she's going on the block and I'm buying a pickup.

 

[RichP]

I'm resurrecting a long dead thread b/c I have the same problem. Any moisture, not just rain - even a morning dew! - makes it supers hard to start. 10 minutes of sporadic cranking normally gets it fired up but it's SO annoying. I have new plugs, rotor and wires. Any ideas are greatly appreciated. If this keeps up, she's going on the block and I'm buying a pickup.

I had a 66 Mustang that had that problem, turned out to be a cracked distributor cap, when the engine was hot it was good, as it cooled down it pulled in nice cool air and I ended up with condensation inside the cap.

 

[winterbeater]

When you did rotor and wires, you must have done the cap too, right?

 

[90xj-65]

Every once in a while I will have this on my 90' after a good rain storm. I just uplug the CPS and snap it together again. The XJ will start the next turn of the key.

Seems to happen more with a good lightning storm.

 

[jdelamater]

Yup. New cap too. did those 1 year ago. Had the problem before that, too. Changing those never fixed it.

a friend said check the bulk head connections and if that doesn't work, replace the coil. I guess we'll see!