This is sort of long winded, but I want to give a complete description of the problem. I have a 94 Buick Lesabre, have had it about 5 years, when we got it, the car ran rough, and when it was getting a tunr-up, the technician noticed that a wire to an injector had been chewed through by a rodent. It was replaced along with the injector, and the car has run fine up until now. About a week ago, pulling from the gas station, the car began stumbling badly. I took it to a friends shop, and he quickly determined one of the cylinders wasn't firing. He then put a test light on the battery, and to test the light, he touched the positive side of the battery, and it sparked.. badly. He knew right away, there was a short somewhere, and decided to taste the injector in the bad cylinder, however as soon as he touched the test light to the injector harness, the car died! Now we have fuel in the rails, and tests fine, but none of the injectors were firing, if we spray some ether into the air intake, the car will start and run. I decided to replace the computer, and have done so. With the new computer in the car, the battery no longer "arcs", and for the first time since we've owned the car, the interior lights also work, but still no injector firing. Ive been told when a computer shorts out, its possible to also short out the temp sending, or oil pressure switch, but it's there an easy way to test these withuot just replacing them? Any other possibilities? Thanks in advance!

Test all under hood and under dash fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-t...tml#post252145

Even though I don't think it's a factor, here's how to test the temperature sending unit:

https://www.askmehelpdesk.com/cars-t...ml#post2043857

Thanks for the quick response, we did test all the fuses, underhood, and in passenger compartment fusebox. I was hoping there was an injector fuse, or fuse-able link, but wasn't able to discover any, nor find any listed on online schematics, (guess that would just be too easy though) :( I'll recheck the fuses again tomorrow, along with the temp sending. Is there anything else that would cause the computer to shut down the fuel? Thanks again!

Perform the tests in the link below:

https://www.askmehelpdesk.com/cars-t...ml#post2123675

Can you hear the fuel pump in the gas tank run, when you turn the ignition key to ON? The fuel rail must be fully pressurized, in order for the injectors to work. Replace the fuel filter and test the fuel pressure.

Honestly, most "crank but won't start situations" are electrical related, not fuel. Be sure the Ignition Control Module (ICM) and coil packs have been replaced in the last 120,000 miles or 10 years. Replace the platinum spark plugs (ACDelco only), if they have not been changed in the last 3 years. Many people don't change the rear plugs on a V-6, because of the hassle. Don't let this be your situation.

Plugs, and wires were recently changed with OEM (Delco), about 6 months ago, (I actually didn't want the hassle of replacing the rear plugs either, so I had it done... hope they didn't feel the same way.. lol). The fuel pump is working, and the rail is holding pressure, (The ICM is also on the list, I'm planning on taking it out tomorrow and having it tested, (even though I've been told they can "test" OK, and still be bad :S Ive also had it suggested to check/replace the crank sensor. The car will start right up, and run as long as you want to spray the starting fluid in her, and even a few minutes after its run that way, it will still start 3-4 times just from the left over fumes).

It wouldn't surprise me, now, if the ICM is the problem. Your fuel system is likely fine.

The ICM may be bad and firing at the wrong time for the injectors; however, it may run temporarily with starting fluid. Interesting situation.

LOL.. at this point, it won't surprise me if I go out tomorrow, and the engine is missing. I guess tomorrow will be another long day... we did test the injector plugs, and get no power to any of them, If I understand this properly, there is one lead that operates fuel that goes through the ICM, (although the person that told me wasn't certain if that was the injectors, or pump). God I miss the days of working on my old Muscle cars...

This is what happens when a body man tries to work on engines... lol

Totally different skill set.

Tell me about it.. lol I swear I've never even just opened a hood without leaving at least part of my knuckles as a "sacrifice" to the "car gods" :S Seriously, I appreciate the help, and ill post tomorrow night the results of the tests you suggest. Thanks again!

Quote:

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Originally Posted by ;

About a week ago, pulling from the gas station, the car began stumbling badly. I took it to a friends shop, and he quickly determined one of the cylinders wasnt firing.

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This was likely the ICM failing. The cylinder was not firing because the "Ignitor" wasn't firing when the ECM wanted it to.

I think you may find out that a compromised electrical system made you think the fuel system was to blame. This is very common. I see very few fuel problems on modern-day cars.

I'll stick my neck out and say this may be a 5-minute repair job, allowing time for coffee.

LOL.. 5 minutes sounds great to me, I did go out and check one of the first items on your checklist, when I turn the key to the on position, all the lights come on, (oil, batt, CEL, etc), however the only one that shuts off is the airbag one, the rest remain on, (not sure if they EVER go out, but they didn't after 5 minutes).

If the CEL does not go out after 2 seconds, a fuse may be bad; the PCM may be failing; the main PCM ground may need cleaning; or the ignition switch may be bad, due to wear, pitting, or melting.

Did you reset the ECM? On your OBD-I car, you may only have to disconnect the negative battery cable for 10 seconds.

Could you hear the fuel pump run?

We can hear the pump run, the computer is new, (just replaced today.. errr.. yesterday now I guess), we had the negative off the battery for installing the computer, did NOT take it off again however after connecting the computer, and replacing the PCM, (Im assuming PCM/ECM is the same.. right? :S).

Is there also a procedure for testing/diagnosing the ICM? Our local autoparts stores don't test them. Thanks again.

AutoZone can test them. However, my experience is that if they test bad, they are bad. If they test OK, they may or may not work. Instead, I recommend replacing them, along with coils, every 120,000 miles or 10 years, whichever comes first. My advice is to shop around for a deal on a new one.

Apparently my size of my booming metropolis doesn't warrant the local Autozones, (and Advance Autoparts), stocking the tester, as none of the local stores, (SEVEN of them), have one. I really hate throwing money at this thing until I happen onto the correct part, but I guess my options are becoming limited.

Im also having great difficulty with finding a shop that will hook up to my "transition year" OBD1.5 The GM Dealer wants $150 to hook it up, and give me the codes.. if I fix those, and it still doesn't start, and has to be put on the scanner again... thats right, another $150..

See if you have a Service Check Connector that will allow you to check for codes. Here's how it's done on Hondas of your generation:

https://www.askmehelpdesk.com/cars-t...tml#post832012

You may want to buy a Haynes Manual for your car.