'90 Cutlass Supreme 3100 PFI

mccabet at mediaone.net mccabet at mediaone.net
Sun Mar 1 04:42:42 GMT 1998


Scott Shotton wrote:
> 
> Fuel injectors are basically solenoids with a specific resistance.
> Temperatrature effects resistance.  If the injector resistance drops to
> far when hot, it could shot down the injector driver.  If it is a banked
> system, you loose three cyls.  When the driver cools, it works again.  A
> condition that requires an increased injector pulse width can magnify
> this problem.
> 
> For example:  GM 2.8 and 3.1 L.  The injectors are under the plennum and
> are exposed to a lot of heat.  If the injectors are just starting to
> fail, you can:  warm the car up, go for a ride, mash the accelerator to
> the floor and the car will instantly die.  Reason:  the demand for fuel
> maxes the pulse width, and because of lower resistance, the circuit
> flows more current which over heats the driver.  I can't count the
> number of 2.8/3.1 injectors I have replaced for this problem.
> 
> I think injector resistance specs for your car are about 12 ohms each.
> Just check them all and if one or two vary by a decent ammount, you
> found the problem.  It is not very likely that all of the injectors went
> bad.  You can save a chunk of change if only one is bad, but some say it
> is a good idea to replace the set.

Scott,
	Thanks for the info.  I finally got to check deeper into this problem. 
It turns out there was one injector about 2.5 ohm, 3 were around 8 ohm
and two were near 12 ohm.  I am replacing the entire set.  I figure, if
I'm removing the plenum, I am replacing all of them.

Thanks to all for the pointers and comments.  I will let you all know
how it turns out after I get this thing back together.

L8r

-- 
Thomas McCabe
-mccabet at mediaone.net
'80 Cordoba, 340, Auto (904) w/ shift kit & 6500 Rpm shift points, 3.23
SG
'83 Cordoba, 318, Auto
'85 D250, 340, Auto
'87 Lebaron, 2.2L Turbo I, Auto
'89 Lebaron GTC, 2.2L Turbo II, A-555 5 Speed, MPSBEC
'96 Dakota SLT Club Cab, Brilliant Blue, 5.2L, Auto, 3.55 SG, 
    Gibson Cat-Back Exhaust, ARE A-234 15x7 rims w/ Dunlop GT Qualifiers
    255R60-15, Molded running boards and flares, Lund bug shield, Cool 
    Fronts, Ventvisors, and Extang Saber Tonno cover.



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