Fuel Injector replace
#1
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Thread Starter
Fuel Injector replace
1994 Le Sabre
In the last year I've notice a very slight surge at low speed with light throttle, also the idle in drive isn't quite as smooth as it was. Most people would not even notice this, but the car has been in the family since new and I can feel a slight difference.
I was looking at the Delphi FJ10035 injectors. There'* some good prices on the net on these.
Any comment/experience with these?
Thanks
Joel
In the last year I've notice a very slight surge at low speed with light throttle, also the idle in drive isn't quite as smooth as it was. Most people would not even notice this, but the car has been in the family since new and I can feel a slight difference.
I was looking at the Delphi FJ10035 injectors. There'* some good prices on the net on these.
Any comment/experience with these?
Thanks
Joel
#2
Retired
Do you actually have a reason to replace an injector beside drive-ability concerns? There are so many other reasons that can cause what you are describing. I would first look at the ignition system, ie, wires, spark plugs, airfilter, fuel filter, fuel pressure etc. Any stored codes?(just because the light isn't on, doesn't mean there isn't a pending code)
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2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
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joeld (10-07-2017)
#3
Senior Member
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Do you actually have a reason to replace an injector beside drive-ability concerns? There are so many other reasons that can cause what you are describing. I would first look at the ignition system, ie, wires, spark plugs, airfilter, fuel filter, fuel pressure etc. Any stored codes?(just because the light isn't on, doesn't mean there isn't a pending code)
Unless you are close to 200K miles, the injectors are the last place I would look. Even then, after I checked everything else.
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joeld (10-07-2017)
#4
Retired
Even at 200k, not too many 3800'* I've seen needed an injector.
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#5
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Thread Starter
Thanks for the replies guys. Sorry it took this long to get back, doing a lot of home remodel.
I should have given more info in my 1st post:
Car has 91454 miles as of today. A list of recent work:
AC Delco plugs #41 installed this past week end
AC Delco wires at 85000 miles
Wix air filter at 90700 miles
New AC Delco TPS several months ago
The real reason I suspected injectors was the resistance readings were really funky. But, I was using a "free" multimeter from Harbor Freight which I really don't trust. I'm going to buy a better meter in a few days and re-check.
Readings cold were:
#1 10.4
#3 10.1
#5 8.8
#2 1409
#4 14.9
#6 13.9
Joel
I should have given more info in my 1st post:
Car has 91454 miles as of today. A list of recent work:
AC Delco plugs #41 installed this past week end
AC Delco wires at 85000 miles
Wix air filter at 90700 miles
New AC Delco TPS several months ago
The real reason I suspected injectors was the resistance readings were really funky. But, I was using a "free" multimeter from Harbor Freight which I really don't trust. I'm going to buy a better meter in a few days and re-check.
Readings cold were:
#1 10.4
#3 10.1
#5 8.8
#2 1409
#4 14.9
#6 13.9
Joel
#6
Senior Member
Posts like a Supercharger
The Buick 3300 (and others) was using the first generation Multitec injectors which were trouble prone at least through '93 (mine is a '92). IIRC, the 3800 did start using something different in '93, but I can't say for sure. My good Multitec are 12.8 and 12.9 ohms with my Fluke 77. The original set I replaced at 200K had a number of them that were lower. They were known shorting when hot and actually shutting the engine down intermittently (at least with the MPI, probably less with SFI). I was getting random misfires and you could actually hear and feel the difference in the injectors when they were acting up.
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joeld (10-07-2017)
#7
Senior Member
True Car Nut
Did you have the meter set to ohms/200?
If you get the same values with a better multimeter I'd consider replacing the #5 injector for sure.
I am pretty sure readings should be around 11.4 to 12.6 Ohms, but looking at yours they may supposed to be like 14.5 Ohms, either way when an injector is off over .5 ohms it is said to be failing.
So if your readings are that far off you will want to replace 1, 3, and 5.
If money is not a problem and it were me, and I was replacing 3 already, I'd go ahead and do all 6 and not worry about them for the rest of the life of the car.
A video to help with the testing, even though obviously you tested them correctly.
Rock Auto has ACDELCO 217307 {#17121296} GM Original Equipment for 24.59 each, not a bad deal, no use in going with the 4x expensive Professional Series ones.
Sounds like they do not come with the o-rings which is odd, you can get a set of rings for them all for 14.59 at RockAuto
ACDELCO 2173102 {#17113544, 19178978, 2171379} GM Original Equipment
If you get the same values with a better multimeter I'd consider replacing the #5 injector for sure.
I am pretty sure readings should be around 11.4 to 12.6 Ohms, but looking at yours they may supposed to be like 14.5 Ohms, either way when an injector is off over .5 ohms it is said to be failing.
So if your readings are that far off you will want to replace 1, 3, and 5.
If money is not a problem and it were me, and I was replacing 3 already, I'd go ahead and do all 6 and not worry about them for the rest of the life of the car.
A video to help with the testing, even though obviously you tested them correctly.
Rock Auto has ACDELCO 217307 {#17121296} GM Original Equipment for 24.59 each, not a bad deal, no use in going with the 4x expensive Professional Series ones.
Sounds like they do not come with the o-rings which is odd, you can get a set of rings for them all for 14.59 at RockAuto
ACDELCO 2173102 {#17113544, 19178978, 2171379} GM Original Equipment
#8
Senior Member
Resistance checks are only good for finding something that is way out of spec, like an open, short, or several ohms difference...
Resistance checking of an injector is not absolute.......let'* say you have 3 injectors in front on a 3800 engine...they all measure 12 ohms....does that mean the injectors are all good?
Not necessarily....flow rates are very important......if the flow rate is out of spec, this can cause a stumble, misfire, hesitation....and many times when you replace an injector, the new one might not match the flow rate of the older ones......that'* why I recommend replacing all injectors on a rail, on old engines....
Resistance checking of an injector is not absolute.......let'* say you have 3 injectors in front on a 3800 engine...they all measure 12 ohms....does that mean the injectors are all good?
Not necessarily....flow rates are very important......if the flow rate is out of spec, this can cause a stumble, misfire, hesitation....and many times when you replace an injector, the new one might not match the flow rate of the older ones......that'* why I recommend replacing all injectors on a rail, on old engines....
#9
Retired
What ^ he just said.
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2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
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2023 Jeep Rubicon Diesel
#10
Senior Member
Posts like a Supercharger
Resistance checks are only good for finding something that is way out of spec, like an open, short, or several ohms difference...
Resistance checking of an injector is not absolute.......let'* say you have 3 injectors in front on a 3800 engine...they all measure 12 ohms....does that mean the injectors are all good?
Not necessarily....flow rates are very important......if the flow rate is out of spec, this can cause a stumble, misfire, hesitation....and many times when you replace an injector, the new one might not match the flow rate of the older ones......that'* why I recommend replacing all injectors on a rail, on old engines....
Resistance checking of an injector is not absolute.......let'* say you have 3 injectors in front on a 3800 engine...they all measure 12 ohms....does that mean the injectors are all good?
Not necessarily....flow rates are very important......if the flow rate is out of spec, this can cause a stumble, misfire, hesitation....and many times when you replace an injector, the new one might not match the flow rate of the older ones......that'* why I recommend replacing all injectors on a rail, on old engines....