91 LX 5.0 wont start

one day just wouldnt start
so i checked for spark on cylinder 1 looks weak replaced coil, Didnt help
pulled engine codes heres what i got
21 coolant temp sensor out of range
22 barametric pressure sensor out of range
24 air charge temp low

Did you have any of those codes beforehand?


[addsig]

Could be anything from weak battery to bad TFI module. If all lights come on and stay bright when cranking, then bat is probably still good. A TFI module will keep it from starting... they can be purchase at auto parts stores for a reasonable price but takes a specialized tool to get the screws out.
http://fordfuelinjection.com/?p=12
Good luck, Ron

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2005-12-09 15:25, Ronbuell wrote:
Could be anything from weak battery to bad TFI module. If all lights come on and stay bright when cranking, then bat is probably still good. A TFI module will keep it from starting... they can be purchase at auto parts stores for a reasonable price but takes a specialized tool to get the screws out.
http://fordfuelinjection.com/?p=12
Good luck, Ron
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
If the battery is relocated to the trunk do you think the ground connection may not be good enough for it to start?

the engine cranks but will not start.

where is the tfi module located?

OK, I'm going to get a little basic so let's run thru the list. Is this fuel injected or carbed? Makes a difference. Fuel injected, turn the key on, with other items off so you can hear, and listen toward the back for the fuel pump to turn on. If it does, then you should have pressure. You gotta have 38-40 PSI in the fuel rail to run.
Carbed car, has to have gas in the bowl.
Spark, Need a friend to help, can be done by yourself with a remote switch on the starter solonoid. Pull the coil wire off the distributor, plug a sparkplug into it and ground it. With key on, bump the starter and see if you have spark. Be careful, this one will make you hurt yourself if you try to hold the wire or plug.
Other thing is timing. Be sure to put the coil wire back on the distributor. Pop the top off the distributor and look at which way the rotor is pointed. Rotate the motor, key off, until rotor points toward #1 plug wire location. On 5.0, that's pointing almost straight back. Now look at the timing marks on the flywheel and see its even close. If you can't see it, you could be on exhaust stroke and 180 out. Rotate it one more revolution and check again. Sometimes the distributor locking bolt can come loose so check and see if it rotates or is locked down. Rotor should point at #1 before the timing mark comes up to TDC.
Baring all those, if you have decent compression, fuel, spark, and its timed right, it should run. A compression tester in each plug hole will test it. Should run between 140 and 165, higher is better. Below 100 and it will hardly run, if at all.
If you had a timing chain break, don't turn it over, you could damage the heads, valves, or pistons. Takes major work to fix, but, some cylinders would show no compression. High mileage motors tend to break them or, can jump timing a tooth AND still barely run... I've seen it.
A lotta work there, go ye therefor and find.

The TFI is the gray module under the distributor that a harness plugs into to. Sometimes they will leave you walking. Any auto parts should have one. Will need the tool above to get it off.



<font size=-1>[ This Message was edited by: Ronbuell on 12/23/05 10:05am ]</font>