Question------------------------- FIRST... THANK YOU SO MUCH! YOUR KNOWLEDGE IS GREATLY WELCOMED. I WOULD LOVE TO SEND YOU A BOTTLE OF WINE....LET ME KNOW. I checked voltage to fuel pump tank it was 12.3 volts. Fuel pump tested at 13 to 15 psi. I tested fuel injectors with timing light and discovered no fuel what so ever coming from injector that had broken wire. (drivers side). I double checked 10 amp fuse (ECM1) that powers injectors, all ok. (This fuse HAD been blown, I neglected to tell you in first letter, I replaced it after repairing green injector wire.) other injector seems to be working fine. What kind of electrical reading should I get at injectors? Do both injectors recieve power thru the same circut/fuse? (Model 220 throttle body)I Rechecked green wire repair to injector in question, I have continunity thru repair. I also changed oil and filter. I didn't proceed with remainder of tests as fuel injector seems to be the problem. Can i replace just one fuel injector? They are not cheap $125.00 for rebuilt thru local napa plus $45 gasket kit. I am ok with spending this much but really want to make sure injector is bad and not power source. This lack of fuel seems to fit with symtoms truck is experiencing.
Followup
Question -
my nieghbors 89 S-10 2 wheel drive with 4.3 v6/auto is diving me nuts. It wouldn't start. I installed new cap, rotor, plugs, wires,and air filter. truck now started but still ran rough. changed fuel filter still no better. Tested grey fuel pump wire running to tank only 8 volts. installed new fuel pump relay, truck seemed to run better. Neighbor called the next day said truck won't run. I inspected all vac lines, all electrical connections to sensors ect, all ok. I found green fuel injector wire in throttle body ground out between spacer and base.(I had not removed this spacer the day before) I repaired wire. runs but still rough and NOW when shifting into drive engine looses power immediatly, starts farting all over itself, sounds like it's loading up and missing. shift to N and engine acts normal again. I have checked stored codes and had a 33 MAP sensor bad. Replaced MAP sensor. Now i have no codes (just12) stored, truck seems to run rough at start up but warms and idles smoothly at temp. still strange loss of power when shifting into gear. I checked the timing and its within 1 degree of specs. Was the fuel injector damaged when wire ground out on throttle body? Could the TCC be my problem? Cat converter? I realize i had more than one problem when i started but still have 1 gremlin i can't find.I would love to hear your imput, thanks so much Cris. other things i have done. checked torque on intake manifold bolts, throttle body bolts, new air cleaner base gasket and throttle body spacer gasket.new PCV valve, checked EGR valve for proper operation. Trans is full of fluid. checked all ground straps. checked all fuses none were burnt. disconnected battery ground to do repairs and reset computer.
Answer -
1. Make sure you have battery voltage, 8 volts is to LOW, at the fuel pump electrical connector at the fuel tank wiring harness connector located near the rear bumper.
2. Test the fuel pump for adequate FUEL PRESSURE and FUEL VOLUME. Pump pressure should be 9 to 13 lbs.
3. Are BOTH fuel injectors appear to have the SAME fuel dispersement. Take your test light and attach it as though you were going to check the timing. However, with the engine running in PARK, turn the advance wheel on the timing light to, IF memory servse 30 degrees and aim it at BOTH fuel injectors and you will see a nice even FUEL CONE SPRAY from the injectors and they should look identical.
4. Unplug the 4 wire electrical connector going into the transmission as this will de-actiavte the TCC solenoid and see IF it runs better.
5. Whenever you disconnect battery power from the ECM (computer) is it VITAL that you drive the vehicle for several miles so the ECM can RE-LEARN it's proper settings.
6. I have encountered many instances when the MAP sensor fails it contaminates the engine oil with gasoline and drives the oxygen sensor NUTS. You should consider changing the oil and filter, I ALWAYS do when a MAP sensor fails.
7. On the TEST LEAD wire for the fuel pump, Take a 10 amp FUSED jumper wire and attcah it to the positive side of the battery and to this TEST LEAD. This will cause the fuel pump to run ALL THE TIME, It will NOT hurt anything. See IF the vehicle know runs.
The grounding of the GREEN fuel injector wire is what controls the GROUND side of the pulse solenoid within the ECM. As long as BOTH injectors appear to have equal spray patterns, I would not be concerned about this wire for now.
Perform ALL of the above and let me know.
autohelp
AnswerYou stated: "Fuel pump tested at 13 to 15 psi.".
ANSWER: That is to HIGH. Should be 9 to 13 lbs.
Are you POSITIVE that your gage is accurate ?. This IS CRITICAL.
IF the gage IS accurate,
Test procedure:
1. Disconnect bOTH electrical connectors at the injectors.
2. Disconnect the fuel return line at the throttle body.
3. Attach a suitable, I use a 5/16th rubber ful line hose to the throttle body side of the return line.
4. Insert the other end into a suitable SAFETY container.
5. Note the fuel pressure when you turn the igition key to the ON position ONLY and the fuel pump will naturally run for 2 seconds. Do NOT crank the engine.
6. If the fuel pressure now reads 9 to 13 lbs you have a restriction in the return line from the throttle body to the fuel tank.
7. If the fuel pressure AFTER doing above step # 5 reads above 13 lbs., Make SURE your test hose from the throttle body and the gage is NOT restricted as sometimes debris from the return port on the throttle body CAN be enough to clog the hose and your gage.
8. If the hose and gage are OK, REPLACE the fuel meter cover which INCLUDES the PRESSURE REGULATOR.
CAUTION: IF this is a dual tank vehicle I NEED TO KNOW as you will have to REPEAT the above tests while switched to the other tank.
YES, both injectors recieve power thru the same circut/fuse.
You should have normal battery voltage at both injectors.
The WHITE and RED wires for the injectors have battery voltage.
The Light Green and the Light Blue are the injector grounds that go back to the ECM.
NO, You should NOT replace just one fuel injector. If you get a hole in one of your shoes, Do you buy just ONE ?. You won't walk very evenly as would be with the worn injector and the new injector.
If you want to see the injectors being turned ON and OFF, Attach a standard 12 volt test light to each connected injector and start the engine and watch the light blink. If you install a test light on EACH injector you will see both lights blink together and at the SAME INTENSITY.
I like to attach 2 ANALOG metrs so I can verify EQUAL voltage to both injectors as the needles on the meters should read at exactly the same time just like your windshield wipers. PROVIDED both meters are calibrated EXACTLY.
That should resolve your problem.
let me know.
autohelp
You can contact me at my personal e-mail address being:
meperganfortis@msn.com
