Ok guys I have a 97 lhs the fuel pump went bad replaced it car ran great again but now it wont start turns over have replaced the fuel filter and the coil pack and still it wont start im stumped please...
this is not unique to chrysler, at all, its EFI.
all EFI works alike , the shapes change to fool the non tech.
i dont know about you, but in my shop
i check fuel pressure and you found it at zero
then put in a new pump and didnt check pressure.
why would you do that? after all it was zero.
and you do that and its still zero. then find a bad wire /connector
in the fuel pump power feed or the fuel pump relay.
or ? a inertial cut out sw, or rollover switch. (i said generic)
now rule 2: if spark is bad, the ECU cuts fuel,
BY DESIGN. that dont mean spark really is bad, but does mean
the ECU can not SEE spark, or that the Tachmeter line is dead.
All ECU monitor spark 1 way or the other, and if that fails.
there WILL BE NO INJECTION period.
use your scan too to see DTCs while cranking and dead RPM cranking for 5 seconds, release key and look for crank or cam
sensors errors, key key on for 1min to see them pop up.
your are stumped because you are not troubleshooting, only guessing. and will make you broke fast.
here at the simple tests, in the proper order.
1: compression on all cylinders. if all are horrid.
the cam timing is way off. no motor will run like this.
2: spark check for spark. ! at all spark plugs, not just one.
3: make sure the ECU is happy about spark, RPM moves cranking , etc.
if spark tips are dry at this moment test fuel can be used.
does it start now then stall as the the test fuel is consumed.?
4: check for injection.
do the injectors click , do all of then click , cranking>?
if all fail, i can assure you the ECU is CUTTING FUEL!!!
if one dont click , then run a NOID lamp test in this injector
and make sure the coil reads near 10 ohms not infinity.
5b: you can do an injector balance test.
cranking, see that the pressure drops, as you crank.
Ill not cover this , as its a SOP proc, in all EFI books published.
but take to bank, can witness the drop in pressure and know the injector does in fact inject.
that way or by looking at fuel soaked spark tips.
the injectors can fail in many a way, they are fuel cooled.
A:shorted coil, open coil
B: ecu driver dead.
C: injector clogged or leaking (leaking causes flooding)
the injector has inside 10 micron screens. tiny,
d: bad fuel. cant burn or clog s screens.
you are now totally confused (above) or are un-stumped.
if you dont understand EFI at all , then lets go back to 1920.
this works too, on all otto cycle engines
1: compression, good, time number of cyclinders.
at spec. all equal, most 150psi to 200 is typical today.
2: got spark times all cycliners.(oh, yes, timing right)
3: over fueling or under.?
that is it, its and air pump , if it can pump air, it's hopeless.
the 3 steps work , every time. the tests are easy and are documented for 90 years, now.
Oct 02, 2013 |
1997 Chrysler LHS