hi I have a 92 caady. Its missing, hard starting, rough idle.. I checked the tps and o2 sensor, ended up at the stealership.. they said I have multec injectors taht are shorted... They want more than the car is worth to fix it.. So i am going to do it myself.. But, my question is how do i know if its really injectors.. i really don't trust the stealership. What test can i do.. The car is a cream puff and only has 60,000 miles on it.. Why are the injectors bad

 

Shorted means that the wiring harness to them shorted I presume. I doubt if the injectors themselves are shorted based on what you posted. If their repair is to replace the injectors then its unlikely all 8 are faulty. Given what you've said you did to diagnose a miss, I would get a second opinion from another shop. I dont think you have the expertise to ck wiring for a short nor the ability to replace injectors. Rebuilt injectors are offered on E BAY for less money than new. My car has 140,000 miles on it and has had one injector replaced because a piece of dirt got in it. So what I'm saying is injectors last well beyond 60,000 miles unless someone applies 12 volts to them which will short them out or somehow the wiring to them is damaged. Each injector has a wiring connector to it which can be individuallydisconnected to isolate the inop injector much like pulling a plug wire to determine a faultly plug or wire on an older engine.

 

the diag you got from the stealership aint worth much.

carnut has given you a better diag w/o even looking at the car.

BTW, the connectors to each injector are more likely to be the problem than the injectors themselves. in my many cars aging (15 to 22 yrs, up to 175,000 miles) fleet, i have never ever, replaced even one injector, however, the connectors have needed cleaning now and then.

make sure you also get yourself a new fuel filter.

 

ok let me try again.. got the car apart.. to check an injector i put an ohm meter on the terminals on the injector.. FSM says normal is 16ohm of resistance. I found 6 in specs and 2 have readings of 3.2 and 4.5.. so those injectors are shorted.. I ordered a set of the Bosch replacements.. they will be here saturday.. I will put them in and report.. This thing has not been running right for a year.. Lets see if the fuel injectors help..

 

well I finally got this car running right. I got the new design 3 Bosch injectors from the Fuel Injector Connection. wwwfuelinjectorconnection.com for 169.00 for the whole set.. Beats 800 from the stealership. I put them in and bingo its perfect.. No more hesitation or stumble.. Started it this morning cranked over in a sec. I am so happy what a difference.

 

with the injectors now out, do the two suspects still show shorts?

 

yes they do still show shorted coils.. I have been reading alot on these multec injectors that gm used between 89- 94,, They are not alcohol complient.. There is an epoxy seal inside the injector that insulates the fuel orfice from the coil housing. When this seal is gone the fuel leaks into the coil causing it to short.. There were serv bulitins on this from AC delco Advising not to clean or use fuel injector additive in the fuel in these years.. When the Multec 2 came out in 95 this problem was addressed. But, they still clog like any other injector.