Fuel injector problems?

Tiny
GATORDOG
  • MEMBER
  • 1995 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 189,000 MILES
My truck statred out by not firieing up after about two to three cranks, then it would start. ( It has always stated up after the first two to three cranks.) Then it started to sputter acting as though it was not getting enough fule. I parked the truck and then it would not start. I checked the spark and its good. I disconnected the fule line after the fule filter and there was gas pressure. I then disconnected the fule lines at the carborator and there was no fule. If you touch the bottom of the injectors a little fule is pressent, but when you crank over the engin you cannot see any fule dispursing from the injectors. I put a little fule into the carb and it fired right up untill the fule was burned up then it would die.
Monday, April 12th, 2010 AT 10:22 AM

23 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Hi gatordog, Welcome to 2carpros and TY for the donation.

Check the injector fuse if okay get a noid lite and hook it up to the injector harness it should be flashing if not could be the injector ground drivers/input power If its flashing test the injectors
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Monday, April 12th, 2010 AT 1:38 PM
Tiny
GATORDOG
  • MEMBER
  • 4 POSTS
How do you test the injectors?
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Monday, April 12th, 2010 AT 1:59 PM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Unplug the injector and use and ohmmeter and measure the resistance on the injector terminal and check if the injector resistance is within specs.
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Monday, April 12th, 2010 AT 5:02 PM
Tiny
DAVID HUDSON
  • MEMBER
  • 1 POST
  • 1994 CHEVROLET SILVERADO
  • V8
  • 102,656 MILES
I replaced my intake gaskets on my 1994 chev k1500 with an 350 k motor with TBI. The motor is running great but since installing the new gaskets both injectors are making a very loud pinging noise. Any advice for me?
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
RACEFAN966
  • MECHANIC
  • 5,029 POSTS
If you would get a can of seafoam and put it in the gas tank next time you get gas it may be that they are dirty. Let me know if that helps. If not then I will need to know if you have a timing light ok.
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
FMERC01
  • MEMBER
  • 1 POST
  • 1994 CHEVROLET SILVERADO
  • V8
  • 2WD
  • AUTOMATIC
  • 195,000 MILES
Injectors in throtle body not shooting out fuel. What controls the opening and closing of injectors?
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Hello, are there any codes? How's the fuel pressure? With the engine cranking, is there any spark at the plugs? The B+ to the injectors goes hot when you turn the key on, the computer switches the ground to control.
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
JEEPBUG
  • MEMBER
  • 1 POST
  • 1993 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 190,609 MILES
When I turn the key on the injectors spray fuel non stop. Cannot get my OBD 1 and 2 scanner to read my truck. Help please.
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
The one of the injectors could be shorted please unplug them and see if it stops, then plug one in at a time to see what happens.

Please let us know what happens.

Best, Ken
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
TOPFUEL
  • MEMBER
  • 5 POSTS
  • 1993 CHEVROLET SILVERADO
Electrical problem V8 Two Wheel Drive Automatic 216k miles

Hi, yesterday my truck would not start. I am getting spark, but no fuel is spraying from the injectors. I removed the fuel line feeding the TBI to check and see if fuel was reaching it, and it is. Not a lot of pressure but it is getting fuel. The TBI is a brand new Holley 670cfm that was working flawlessly up until the no start. The engine has been rebuilt but no problems to speak of until this. Fuel pump is the original so maybe its time to be replaced? Checked the fuses I could find in my diagram and they are all good, wiring looks sound going to the TBI and injectors. Just don't know why the injectors aren't spraying any fuel after trying to start multiple times.

Thanks in advance!
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
What you need to do here is check the actual fuel pressure with a fuel pressure gauge designed for your fuel system

Here is a guide

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

if okay-check for power to the injector/s-got power still no pulses-could mean the computer ground drivers has gone bad

Here is a guide

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Check out the diagrams (Below)

Please let us know what happens.

Cheers
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
TOPFUEL
  • MEMBER
  • 5 POSTS
Checked fuel pressure to TBI, its sitting at 13 There is power going to the injectors, what else would cause this problem?


https://www.2carpros.com/forum/automotive_pictures/278243_IMG_0920_1.jpg



https://www.2carpros.com/forum/automotive_pictures/278243_IMG_0919_1.jpg

psi.
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
TOPFUEL
  • MEMBER
  • 5 POSTS
New thought, I recently had a car security system installed, could this have somehow caused a problem so suddenly a week after installation?
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
If it has to do w/the security system it won't last a week. Hook up a noid light to the injector and see what happens-if its not blinking its not pulsing could be the computer ground drivers -or the computer is missing an ignition reference signal from the cam/crankshaft sensors therefore not synchronizing the injectors.
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
KONUN
  • MEMBER
  • 3 POSTS
  • 1992 CHEVROLET SILVERADO
  • 200,000 MILES
Hard starting for past couple weeks until not starting at all. No fuel coming from injectors. Fuel pump 2 years old. With ignition turned on, pump makes whirring sound. Pump ok. Fuel filter changed last week. Today I changed both injectors, fuel pressure regulator kit, and pump relay. Afterwards I attached each injector electrical connector with a test (noid) light and cranked the engine over. No light flashes on either one. The book said then you need to look at the ECM, so I replaced it. Still the same result.
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
TOPFUEL
  • MEMBER
  • 5 POSTS
I don't have a noid light and its a too late to buy one today, but I threw a voltage meter on it and only saw constant current when the motor was cranking, no pulsing, then again the meter probably isn't fast enough to see the pulses. I guess i'll pick one up tomorrow. Thanks much for the help so far!
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
What is the exact fuel pressure?

The distributor send a signal to the ecm to toggle the injectors.

Roy
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
TOPFUEL
  • MEMBER
  • 5 POSTS
Hi again, tested injectors with a light and its not blinking at all on either injector. Checked for codes and its showing code 12 (No Problems detected). So I replaced the ECM and the truck started it was bad. Thanks for your help
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
KONUN
  • MEMBER
  • 3 POSTS
I do not know the exact fuel pressure.
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Friday, August 21st, 2020 AT 9:47 AM (Merged)
Tiny
BARFARMER
  • MEMBER
  • 1 POST
I have a 1993 Silverado that has don that more than once. In each case it was the Distributor. I bought a dist at Auto Zone with a lifetime warantee and they have to replace it about every 2Yr. You will think it is a fuel system problem but it is not. I have had this problem on another 1993 chevy custom with a 350 engine 2 times and my own at least 4 times hope this helps.
Keeps AAA in the Rollback business too ha ha
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Friday, August 21st, 2020 AT 9:47 AM (Merged)

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