Checking for leaking injector Bosch III
Thread Starter
Racer
Joined: Sep 2011
Posts: 462
Likes: 30
From: Riverside California
Checking for leaking injector Bosch III
Checking for a possible leaking injector, 93 LT1 stock.
Question: with the fuel rail removed and lifted enought to see if any are leaking, will the Bosch III's stay in the rail with pressure applied from the pump? No clips on the rail with the Bosch III.
Thanks
Question: with the fuel rail removed and lifted enought to see if any are leaking, will the Bosch III's stay in the rail with pressure applied from the pump? No clips on the rail with the Bosch III.
Thanks
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
Maybe but unlikely, if none are leaking. One should pop out. Leave the retaining clips in place. It works out better if they stay where they belong. If injector(s) leaks change it out and re-evaluate.
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 763
w/ aklim, you could send them to Jon at FIC for cleaning/testing, OR if you're creative, you can jury-rig and small test stand and bench test for a leaking/clogged injector (plenty of youtube videos out there). to the OP, why do you suspect a leaking injector? symptoms???
Last edited by Joe C; Jul 16, 2016 at 04:35 AM.
Thread Starter
Racer
Joined: Sep 2011
Posts: 462
Likes: 30
From: Riverside California
as the OP said, no clips used with boschIII's. I would say, that lifting the fuel rail, and applying, key on, 40PSI fuel pressure, should be enough to blow those injectors right out of the fuel rail. I wouldn't do it!
w/ aklim, you could send them to Jon at FIC for cleaning/testing, OR if you're creative, you can jury-rig and small test stand and bench test for a leaking/clogged injector (plenty of youtube videos out there). to the OP, why do you suspect a leaking injector? symptoms???
w/ aklim, you could send them to Jon at FIC for cleaning/testing, OR if you're creative, you can jury-rig and small test stand and bench test for a leaking/clogged injector (plenty of youtube videos out there). to the OP, why do you suspect a leaking injector? symptoms???By the way did get the III's from FIC, replaced them last fall.
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 763
Been looking for a miss at idle, wanted to make sure the fuel system checked out which it did. Got a pressure guage on it last night before pulling the injectors, pressure held right at 40 lbs for 15 minutes, and was still at 20 lbs 2 hours later. Took it into a shop last week and it's new opti time. They said they didn't check the fuel system and suggested I check it. So with the pressure holding good have to assume their is no leak.
By the way did get the III's from FIC, replaced them last fall.
By the way did get the III's from FIC, replaced them last fall.
Thread Starter
Racer
Joined: Sep 2011
Posts: 462
Likes: 30
From: Riverside California
Checked ohms yesterday, cold reading 15.1-15.3.
Just went out and checked the pressure guage, left it connected over night. When I turn the key on pump runs, but zero reading on guage? Turned key a couple of times still zero. Everything from the fuel pump, filters and FPR are new. No gas in FPR. Did hit the release valve on the pressure gauge, about a tablespoon of gas came out, but the gas was a light brown color. Most of the premium gas I've seen is either light pink to no color at all. I'm going to siphon some out of the tank to see if the gas is clear.
The shop, not a dealer, but a very good shop had the car for a couple of days to look for what was causing the miss. The only thing they could find was a rich condition and the oscilloscope did show signs of the opti or ignition not normal. All plugs are firing, new plugs, wires, ICM & coil, recently.
The miss is in drive stopped at a light, almost feels like it wants to stall. In park or neutral it's not as bad. Runs great at speed.
I'll check the injectors with a Noid and let you know what I find!
Thanks
Just went out and checked the pressure guage, left it connected over night. When I turn the key on pump runs, but zero reading on guage? Turned key a couple of times still zero. Everything from the fuel pump, filters and FPR are new. No gas in FPR. Did hit the release valve on the pressure gauge, about a tablespoon of gas came out, but the gas was a light brown color. Most of the premium gas I've seen is either light pink to no color at all. I'm going to siphon some out of the tank to see if the gas is clear.
The shop, not a dealer, but a very good shop had the car for a couple of days to look for what was causing the miss. The only thing they could find was a rich condition and the oscilloscope did show signs of the opti or ignition not normal. All plugs are firing, new plugs, wires, ICM & coil, recently.
The miss is in drive stopped at a light, almost feels like it wants to stall. In park or neutral it's not as bad. Runs great at speed.
I'll check the injectors with a Noid and let you know what I find!
Thanks
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
If your car sits a lot the fuel senders are known to rust. Pull the sender from the tank. Look for very fine brown particles on the bottom of the tank. The particles can get past the fuel pump sock and the fuel filter on the frame rail. They can damage the fuel pump and cause injector problems.
Last edited by Hooked on Vettes; Jul 16, 2016 at 11:30 AM.
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Team Owner
Joined: Jul 2004
Posts: 28,430
Likes: 3,283
From: Hartford WI
Checked ohms yesterday, cold reading 15.1-15.3.
Just went out and checked the pressure guage, left it connected over night. When I turn the key on pump runs, but zero reading on guage? Turned key a couple of times still zero. Everything from the fuel pump, filters and FPR are new. No gas in FPR. Did hit the release valve on the pressure gauge, about a tablespoon of gas came out, but the gas was a light brown color. Most of the premium gas I've seen is either light pink to no color at all. I'm going to siphon some out of the tank to see if the gas is clear.
The shop, not a dealer, but a very good shop had the car for a couple of days to look for what was causing the miss. The only thing they could find was a rich condition and the oscilloscope did show signs of the opti or ignition not normal. All plugs are firing, new plugs, wires, ICM & coil, recently.
The miss is in drive stopped at a light, almost feels like it wants to stall. In park or neutral it's not as bad. Runs great at speed.
I'll check the injectors with a Noid and let you know what I find!
Thanks
Just went out and checked the pressure guage, left it connected over night. When I turn the key on pump runs, but zero reading on guage? Turned key a couple of times still zero. Everything from the fuel pump, filters and FPR are new. No gas in FPR. Did hit the release valve on the pressure gauge, about a tablespoon of gas came out, but the gas was a light brown color. Most of the premium gas I've seen is either light pink to no color at all. I'm going to siphon some out of the tank to see if the gas is clear.
The shop, not a dealer, but a very good shop had the car for a couple of days to look for what was causing the miss. The only thing they could find was a rich condition and the oscilloscope did show signs of the opti or ignition not normal. All plugs are firing, new plugs, wires, ICM & coil, recently.
The miss is in drive stopped at a light, almost feels like it wants to stall. In park or neutral it's not as bad. Runs great at speed.
I'll check the injectors with a Noid and let you know what I find!
Thanks
Thread Starter
Racer
Joined: Sep 2011
Posts: 462
Likes: 30
From: Riverside California
Here's something new:
Had to hit the key on switch 5 or 6 times to build pressure
Started engine fuel pressure at idle 34#
Shut off engine pressure holds at 34#
Relieve pressure guage to zero
Within a few minutes pressure climbs back up to 40#(key off, released pressure at gas cap no change).
Could I have a plugged fuel filter? Something is building or holding pressure in the fuel rail?
Any suggestions?
Thanks
Had to hit the key on switch 5 or 6 times to build pressure
Started engine fuel pressure at idle 34#
Shut off engine pressure holds at 34#
Relieve pressure guage to zero
Within a few minutes pressure climbs back up to 40#(key off, released pressure at gas cap no change).
Could I have a plugged fuel filter? Something is building or holding pressure in the fuel rail?
Any suggestions?
Thanks
Thread Starter
Racer
Joined: Sep 2011
Posts: 462
Likes: 30
From: Riverside California
That is kinda normal. You should hear the pump run once and the next couple of times (within a certain time period) it won't re-prime. You might have to wait a minute or two, IIRC. However, not getting a pressure is abnormal. If the pump runs, you should get pressure. Check it at the terminal to see if it is getting power and how much. That the pump moves doesn't mean it is getting good pressure
Gray wire 12.4 key on holds for 2 seconds..
Next I'm going to check pressure at the fuel pump...not till tomorrow off to a wedding. Will advise what I find?
Thanks
Thread Starter
Racer
Joined: Sep 2011
Posts: 462
Likes: 30
From: Riverside California
Follow up
Fuel pressure at the pump (measured at fuel line out of tank) 100 lbs
Fuel volume (pump run for 2 seconds key on) 4ounces..
Fuel pressure at rail 0, would go up if pump was primed 5 plus times or would climb up after key turned off.
See attached photo of the gas from the bottom of the tank, picked up by fuel pump when measured the volume.Looks more like diesel fuel, not gasoline.
My thinking is the fuel filter is plugged, so the next step is to empty the tank, clean out the junk, new filters pump and fuel line. Fresh gas and keep my fingers crossed that I'm on the right track
Thread Starter
Racer
Joined: Sep 2011
Posts: 462
Likes: 30
From: Riverside California
That's what I have in there now, just ordered a new filter sock from Racetronics and new AC Delco fuel filters
By the way I don't think Racetronics sell "pimp" kits! �� Got to love that auto correction.
Have a great week.
��
By the way I don't think Racetronics sell "pimp" kits! �� Got to love that auto correction.
Have a great week.
��
Team Owner
Joined: Jul 2004
Posts: 28,430
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From: Hartford WI
