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LED tail light modification

If you recently pumped your ride with LED lamp and suddenly you get many error messages, and the autocruise dont work. the ECU got confused.
its probably the LED lamp having a low resistance compared to the original bulb.

try get hold of the original bulb, measure its resistance and compare it to the LED.

then, add a series resistor to increase the resistance back to default value.

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2 Answers

The service engine soon light will not come for pretest before starting engine. It is an automatic fail for emissions test. 2002 gmc sierra.


This could be something as simple as the Service Engine Soon light bulb being burned out. Removing the instrument cluster isn't too terribly difficult, but if you can carefully pull it out of the dash, look behind where the bulbs are located and see if that one happens to be burned out.
I hope this helps! :)

Jun 11, 2014 | Cars & Trucks

1 Answer

injector not fireing


you have a TBI 8valve engine. just like my 91
the injector , not firing, so by guy method.
1: it dont click? (sonic ,stethoscope)
2: the noid dont flash. (use a noid lamp and win)
3: it dont squirte, watching it with eyes, cranking,

if the noid fails, that means ECU is bad or one of 3 inputs to ECU are dead.
if noid works, that means, the injector is cogged, it has 10 micron screens that are easy to clean. or there is no 35 PSI fuel pressure.

here is the page just for that.
  1. THE ECU IS PROGRAMMED to cut fuel if there is no spark preventing TV like crashes and burns. (and other fire reasons)
  2. the tests are all easy. no order but #1 is #1
  3. fuel pressure at spec.
  4. injector coil reads 1.0 OHMS.
  5. injector clean. (there is only one, so all hope is just here)
  6. noid lamp fails , so is CMP dead? or TPS TP pin stuck high or , ecu throwing code 41./42s errors, BINGO!

http://www.fixkick.com/INJECTORS/injectors.html

or no starts

http://www.fixkick.com/INJECTORS/injectors.html

May 06, 2014 | 1992 Geo Tracker

1 Answer

1991 honda accord turns over wont start . when key in second postion no lights on dash exept for battery light


blown fuse.
the CEL lamp must glow, or the ECU is dead. (no power)
the CEL is very important lamp telling you the ECU has power
and it thinks(sic) that it is ok, (basics)
if the lamp is burned out, it become hard to work the ECU.
as this ECU flashes codes for errors,
check all fuse. in both boxes.

Feb 05, 2014 | 1991 Honda Accord

1 Answer

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 someone that knows chryslers HELP


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

3 Answers

no power going to the fuel pump... 1994 toyota corolla


4afe or 7aFE engine?
as always for ever and ever, check all fuses.
check it cranking some ECU dont power pump until cranked.
the ones that key on power are 3second, can you run that fast?
no. so crank.
if the fuel pump relay closing and sending full 12vdc to pump wire.?
no?
then fuse is blown
if cel lamp is not on key on fuses, are blown or lamp or ecu bad.
fix lamp first it must glow, that glowing means ECU passes, basic self tests. (like a pc doing P.O.S.T) (i rebuild and tune ECU's)
do you need a schematic,(alldata.com has it)

books are amazing things, no? im looking here, seen it many times.
the magic fuel pump relay on the 4AFE.
it is really a 2 coil relay forming what is called logic "AND"gate
7a works same,.... just looked
the ECU enables coil A with LC command line (software) 0v here.
the main relay must close and 12vdc out to pump relay
then the driver cranks, and relay coil B is activated. and pump spins.
always crank and test. see why?
if you need bigger photo ask, .....
if the relay fails to close cranked, check that the crank
signal makes it to (12v) to top left coil below.
if not there will NEVER be fuel. see crank sig below in red.



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Mar 28, 2011 | 1994 Toyota Corolla

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