Folks,

It's been awhile since my last post on this topic. My '97 Expy still has a problem with dying right after the truck starts. I know most times changing the IAC vavle fixes the problem, but not so in my case. I even took the truck to a shop in town (no Ford dealer) and they have failed to fix it twice. Even though I explained the problem, and my line of thinking, the mech keeps going back to a fuel problem.

Today when it first died (cold engine) I disconnected the small vacuum line going to the top of the EGR valve. The truck started up on the next try, so I reconnected it and drove to the shop. Later when the truck was warm (sitting maybe 15 minutes max) it failed to start again, so I removed the vacuum line and it started up, but took longer (more cranking time.) The problem is so intermittent that it's hard to tell if it's the removed line, or the truck would have started anyhow.

Right now I've noticed that this valve...



...makes a light 'groaning' noise after shutting down the engine. At first I thought it was the EGR valve, but placeing a finger on top the valve in the picture causes the noise to stop, and a vibration can be felt.

I have tested the EGR valve by starting the truck and applying a bit of vacuum to the valve. It causes the engine to stumble and nearly die. I've traced vacuum lines all the way to behind the battery. No leaks or cracks were found.

My current plan is to call for yet another appointment at the local shop (it's the best in town, but that ain't saying much) and while waiting, play with the system of disconnecting the vacuum line at the EGR valve each time it fails to run after starting.

Thoughts?...

 

Will it stay running if you give it just a little bit of gas?

 

Hmmm...

The picture is not working right now. That sometimes happens with Sony ImageStation. If needed, I'll host it a Photobucket.

Anyhow, not with a 'little' gas, but with a lot of gas, it will sometimes stay running. It doesn't work for me, as I'm not willing to do that to the engine (high revs with little oil pressure while starting) but I've seen my wife do it a few times with success. Guess she doesn't understand the principle of oil protecting little things like crankshaft bearsing.

 

Hows this picture?

 

Anyone care to guess the name of that valve? The electrical wire going to is labeled "EVR".

 

Evaporative Vapor Recovery?? I can hear mine doing that too, I thing. It last for like a second or two when I shut it off. So I am guessing that this is normal.

 

Well, that's good news. One less thing to change. Anyhow, what's the verdict on your question about being able to force the truck to run with lot's of throttle?

Thanks

 

I would check the fuel pressure when it is acting up. It should be 32-40psi. I wonder if it is taking awhile for the pump to build pressure.

 

lxman1,

Got the truck into the shop again, and now they think it's in the anti-theft system. At least that's the code he got after it didn't start for him. That might explain the low/no fuel pressure theory both you and the mechanic have mentioned. Now I do recall some interesting facts about this problem. When the truck would die, it absolutely would not restart (even to just die again) unless the key was turned all the way to the 'off' position. Releasing the spring pressure back to 'run' then turning it again to 'start' produced only cranking with no starting at all. Also, and I'm not sure this is a factor, when cranking the engine for a long time waiting for it to start, occasionally all the door locks would lock then unlock all by themselves.

Do you think the mech is on to something here? If so, what would be a good fix, as I believe he just reset the codes and wants to check them again when this happens again. I'll do a search on the 'anti-theft' system here at this forum, but hope you may have something specific.

Thanks...

 

Try another key. It could have a failing chip in it.

 

Hi,

I just read this thread. I have '03 F150 SC 4.6L with 40k miles. Recently I filled up at a Sunoco station and since then have experienced similar stalling except it seems to always happen when hot. When cold it has not happened. If I stop for a couple minutes and then start, it seems to rev higher than normal then stall out after I put it in reverse. On restart I can give it a little gas and keep it running, sometimes after a couple tries. After I get it going and in gear it runs fine.

This does not happen every time. I just ordered a Diablo Predator. I will check to see if there are any codes. Will report back.

 

could be a dirty maf have u checked for vacume leaks along the PCV? what alarm system do u have?

 

My Predator does not show any error codes and now I have 93 Octane gas and the Diablo Tune installed. I am still having trouble if it is idling and I rev the engine up it stalls when it slows back down. I have to give it a little gas when I restart it and it will finally "catch" up. I think this may be a different problem than yours.

I removed my IAC valve and cleaned it but it did no good.

Good luck

 

The IAC motor could be bad, It probably wouldn't hurt to change it.

 

SITKA, LXMAN1 IS RIGHT REPLACE THE IAC MOTOR.
MY 99 EXPY DID THE SAME THING CHANGED THE IAC STARTED RIGHT UP RAN GREAT