Sounds very much like the fuel pump relay. Open the relay box on the
passenger side, under the hood. Swap the A/C relay with the fuel pump
relay- each has an unused pair of contacts, and they are opposites so
they will be good as new.
If that doesn't do it, another common problem is the crank position
I don't have personal experience with the crank position sensor, but
if you search this newsgroup you'll find info like this:
Here's some good info from Dr. Bob on the crank position
"The crank position sensor is the hall effect sensor pointing to the
front of the crankshaft. The hub behind the front pulley has grooves
machined in it, with one groove missing. the sensor reads each of the
pulses from the grooves to know exactly how far the crankshaft has
turned, and reads the missing groove to re-identify a known position
to reference from.
This allows the ignition and fuel injection systems to make sparks and
fuel at the right time.
There is a 'limp home' mode, as you have discovered, that allows the
engine minimum operating ability so you aren't stranded.
A failed sensor generates an error code, so the diagnosis is fairly
straightforward. If you weren't at a Ford dealer, the $200 is the
result of not having the right code reader. The sensor takes mere
minutes to change."
Here's a description of the problems it causes:
"The crank sensor went out last fall on our '92 XL, too. The car would
suddenly die and wouldn't start again. After about 10 minutes, it
start up fine and run like there was nothing wrong (until it would die
again, usually days later). Finally, it would run only poorly (the
"limp home" mode, I guess)."
OK, down to basics. To start you need:
2. proper fuel/air mixture
At least one of those is missing.
1. Have someone crank it while you check for a spark. Create an 1/8"
gap to ground somehow- old spark plug, nail, screwdriver, whatever.
However, you should have an error code if the ignition system is not
2. Listen near the gas tank while someone turns the key to run. You
should hear the fuel pump run briefly. Next check the fuel rail for
pressure. It runs along the top of both heads, connecting to each fuel
injector. Look for a schraeder valve, like on a tire. Have someone
turn the key to run for a few seconds, then off, and see if there is
pressure in the rail. Needless to say, there is some danger involved
here. Don't be spraying gas all over, smoking, etc. The spec is 35-45
psi, key on, engine off. It is supposed to drop 10 psi when the engine
starts. If you don't hear the fuel pump run and there is no fuel
pressure, you have narrowed it down to the fuel pump or the fuse and
wiring to the pump. There is also a fuel pressure regulator which can
fail, in which case the fuel pressure will be wrong.
3. You should have an error code if you have a crank sensor or other
timing related problem.
4. I'm sure you'd know if you had no compression in all 6 cylinders.
I checked for spark. Pulled plug, attached plug wire, laid on
alternator, cranked. No spark. Used different plug wire, no spark.
Also, for some reason the code reader doesn't seem to be working.
I had disconnected the battery and reconnected. The alarm kept going
Should I be able to smell gas once I removed a plug?
Well, if you have no spark I think you've narrowed it down
considerably. It ain't gonna start without a spark. The alarm going
off may have something to do with it, I think that also kills the
ignition. You need a working code reader now, it sounds like it's not
something simple and easy to diagnose, like a fuel pump problem.
I don't have a problem with the alarm anymore, I think.
I just used the code reader a month ago and it worked fine, that how I
replaced the EG sensor.
I hooked a fuel pressure gauge, but that doesn't register (fuel did
come out of the valve). Does the engine need to be running?
.45 round thru the block :-)
Apparently I was impatient with the code reader. I went back out and
it had cycled thru and came back 111-system pass.
Additionally, the fuel pressure gauge had a reading of 38PSI.
Guess that leaves just the spark issue!
I'm not POSITIVE, but I'm pretty sure it will give a code for things
like the crank position sensor failing. This is a gross failure, not
something like one cylinder miss firing.
But I'm too lazy to look it up, and if anyone knows for sure I'll
defer to their greater knowledge.
Now it gets really bizarre. When I finally got the reader to cycle
thru the test I heard the fuel pump run and then the fuel pressure
gauge shot up to 40psi then dropped to 37/38psi and the pressure held.
Then I was able to start the engine. I then shut the engine and
disconnected the fuel pressure gauge.
I tried to start the engine again with no luck.
I reconnected the code reader and ran it thru the test cycle, at least
until I heard the fuel pump run. Then the engine started.
What the #$%& would cause the fuel pump run when the code reader is
connected, but not when I turn the ignition on.
By the way, I still had no spark, therefore I must not have had it set
up correctly and spark all along...I guess.
My code reader resets the fail codes after 3 cycles of reading them.
So if the computer is sensing a code that tells it to cut off the
spark or fuel, that is a possible explanation.
But this is getting beyond troubleshooting by text messages.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.