Intermittent start on 99 EB

[slayne]

Like other X owners I have the intermittent starting virus. I have a 99 EB 4.0 SHOC with about 94K miles. The intermittent start has been going on for about a year now. I have searched many of the articles on the forums looking for a solution trying various solutions suggested. Fuel filter has been replaced twice and fuel pressure is about 58 PSI and but does bleed down over the course of an hour or so. I've done the FPR and PCM relay swap as well as checking the inertia switch and they all seem to be OK. One thing I have noticed is that when the intermittent start happens I don't hear the fuel pump run. After several retries the pump starts pumping and the X starts except when my wife drove it 90 miles away and couldn’t get it to start. After starting it runs fine. This problem seems to present itself more as it gets cooler. Lows are in the high 40s with morning dew. Can a fuel pump die over a long period or do they just quit working? Could it be the crank or cam sensor possibly? I have not replaced either of these sensors. Are they part of the starting circuit and could they interrupt power to the fuel pump when starting? Any ideas would be greatly appreciated.

 

[Creatve]

did you ever fix your problem? that is exaclty what am experiencing with my vehicle now though my fuel pressure is at 66psi with the vehicle running and drops down to 20psi within a minute after shutting off the vehicle. its been happening fequently now that its colder (32F)
whenever i have problems starting, i dont hear the fuel pump hum in the beginning and theres less than 6psi pressure in the fuel.

 

[Cobraguy]

If it's intermittent, you more than likely have a short somewhere...open or closed. It can be as simple as a loose connection that can be worse with cold temps as materials contract away from each other, or as miserable as a broken wire inside the insulation. (let's hope it's not that) Right now, the most logical choice would be to check all connections and make sure they are clean and tight. This definitely includes ground connections. Also be sure to check the inertia switch connection. In fact, for testing purposes, you might want to bypass it and make sure it doesn't have an intermittent problem. Then I would pull all related fuses and make sure they are clean and not corroded. Then I would just flat replace the relay. Make sure you get a good, high quality relay. And I'll tell you one other circuit I would check...and that's the PCM circuit. If it dies, you would get the same issue. Again, check fuses for clean, connections, and replace that relay too. If all that fails, my next suggestion would be the fuel pressure sensor in the tank. Where this is so intermittent, it's just going to be a ***** to find.

I just thought of something...if you are losing power to the PCM circuit, then you should be able to pull codes and get a P1000 code. If it doesn't have that right after this has happened, the PCM is not losing power. That doesn't mean however that the PCM circuits for the fuel system shouldn't be checked for shorts.

 

[Creatve]

I've checked the fuses/connection and the relay. I didnt replace the relay, i just swapped the relay from my horn relay and it still has the same problems. I havnt check the PCM or know what the PCM is lol. Is it that thing on the top of the firewall close to the passenger side that looks like a cartridge with wires sticking out of it?

Would it be safe to say that the fuel pump is ok? i've been told the fuel pump usually either works or it doesnt, never in the middle. im worried with this condition happening practically every time i start the truck that my starter may go out soon or even worse my car wont start at all.

I've been trying to find the fuel pressure regulator but i cant seem to find it on the fuel rails.

 

[marragtop]

As cobra stated, check the connector on the bottom of the inertia switch. I had the same problem on my 95 and was ready to put a fuel pump in (which should be the last resort). Part of my trouble shooting process was to bypass the switch at which point I realized the connector was loose. If the connector is loose, it will not be in reset mode so you have to check the connector itself.

 

[96eb96]

A good PCM test is to make sure the check engine light goes on when you first turn the key to run. Then it should extinguish when the engine starts up if you have no codes.

 

[Creatve]

ok i checked the inertia switch connection and its good but wouldnt the fuel reset light trigger intermittently if the connection was loose? my pcm seems to be good, theres no check engine light and i read the codes and no codes are found. thanks so far but i still cant figure out where the pressure regulator is heh.

 

[outdoorman99]

i'm going through the exact same problem. have you found a fix yet? And where would i find the inertia switch?

 

[Creatve]

...where would i find the inertia switch?...

you should find it behind the passengers side kickpanel

 

[merrillf]

My 2001 XLT also has the same disease. Seems to surface mainly when it is cold, if it's fully warmed up it starts and runs like a new car. I replaced the fuel pump relay and reset the inertia switch, no change. I read one post that the rf device in the column maybe wasn't always recognizing the chip key, tried that..nothing. Next I will check fuses, maybe try another relay then I don't know. We need a Ford Master Tech to find the magic bullet solution as it sounds pretty common.

 

[marragtop]

When you encounter the no start situation, do you hear the fuel pump run for a second or 2 when you turn the key to the ON position? If not, then your problem is fuel delivery related. When you reset the inertia switch, did you check to make sure the connector is on tight at the bottom of the switch?

 

[outdoorman99]

The dealer replaced my ignition control module. Cost me about $430 bucks. Never had the problem after that. Had the fuel pump replaced before that for $700 which did not solve my problem. (it was a little low on the pressure) Hope this helps!