Ok I Give Up!

:banghead: I came to this forum about 6 months ago with my 99 3.4 70,000 mile alero not starting.well its been a nightmare and still no start.It was running like new the night i parked it in my driveway.the next morning i turned the key and it turned over but wouldnt start .ok here i go...Ive changed the fuel filter,the fuel pump modual,the fuel regulator,the injectors,the MAF sensor,The MAP sensor,Ive checked the temp sensor,i have spark on all plugs .i can spray starting fluid in the intake and it will run.I finally decided to bite the bullet and had it towed to the dealer.I get a call from then saying i need a new engine!!!!!.WTF.they said there is a noise when it was barely running .i new that it does make noise when it isnt getting enough fuel but runs great when spraying starter fluid.I Dont get it?-Also ive noticed a security light comes on that i didnt have before.That strange since i dont have any security,no chip in my key.Help.:screwy:

When that SECURITY light comes on it will not start. Fuel pump enable is disabled. Your Alero has the Passlock anti-theft deterrent system. Passlock does not use a chip in the key like Passkey I/II.

Try the key relearn. With ignition to on, not start leve the key in the ignition switch for at least 10 minutes until the light goes out. Ignition to off and then try starting.

When that SECURITY light comes on it will not start. Fuel pump enable is disabled. Your Alero has the Passlock anti-theft deterrent system. Passlock does not use a chip in the key like Passkey I/II.

Try the key relearn. With ignition to on, not start leve the key in the ignition switch for at least 10 minutes until the light goes out. Ignition to off and then try starting.ok ill try

As a side note, I had an alternator go on mine and after I replaced it and the battery, I left it in the on position for 14, (The clock reset to 1:00 so it was easy to tell the time.), minutes and the light didn't go out, but when I then turned it off and back up again it did start. So the light may not go out, but waiting did seem to reset the system.

I thought I would add this just in case you waited for the light to go off and it never did.

well thanks for the help.i have gotten a new battery and had the alternator checked .The security ligh stays on.Could it be my ignition switch maybe?

well thanks for the help.i have gotten a new battery and had the alternator checked .The security ligh stays on.Could it be my ignition switch maybe?

The ignition switch key cylinder has the transponder module which in turns sends the proper code to the body control module (BCM). The BCM provides the fuel pump enable signal to the powertrain control module (PCM). So it is possibility. Someone posted a bypass procedure for Passlock for your type problem but I am not sure it will work.

The ignition switch key cylinder has the transponder module which in turns sends the proper code to the body control module (BCM). The BCM provides the fuel pump enable signal to the powertrain control module (PCM). So it is possibility. Someone posted a bypass procedure for Passlock for your type problem but I am not sure it will work.the thing is i can hear the pump when i turn the key ,along with fuel pressure i put a gauge on.the injectors are not injecting .still a passlock problem?

the thing is i can hear the pump when i turn the key ,along with fuel pressure i put a gauge on.the injectors are not injecting .still a passlock problem?

I doubt it since you are getting fuel pressure. Also, does the engine crank? Sounds like the Security light is just staying on but not really affecting anything.

How did they determine your engine was bad?

:banghead: :banghead: :banghead: :banghead: They said they had it going for a few seconds and it was makeing alot of noise.I have heard the noise they are talking about ,but thats because it isnt getting enough fuel .It runs fine without any noise when i spray starting fluid.The injectors have 12v to them they just are not getting the ground signal from the PCM.Bottomline is the engine doesnt go bad sitting in my driveway over night.Again thanks for your time

The problem doesn't make sense but I recall you replaced just about everything or at least checked. If the fuel pressure is good at the rail then the fuel injectors are getting fuel to a point, however, maybe the fuel injector pulse from the PCM is bad. The problem is it is impossible to check with a noid light due to no place to hookup the test device.

Have you done anything to the PCM module?

Well actually i tried a PCM out of another 99 alero and had the same results.When i put the key in and turn it it kinds sticks a little bit thats why im thinking its something in the ignition switch .i dunno ,as you can imagine its quite frustrating

Veeery interesting case! We need to review a few things.

So the dealer gets it running for a few seconds, hears a noise & then tells you the engine is shot. Did they tell you what they heard or what they think is wrong with the engine?

It runs while spraying starting fluid so we can rule out ignition problems. How long would it run with the starting fluid?

You said you checked fuel pressure at the rail. I'm assuming you checked this while someone was attemping to start it - correct me if I'm wrong. What was the pressure?

Have you tried checking the throttle position sensor?

The dealer said "Theres something going on in the engine"-"you need a new one,its makeing some noise"....$4300 parts an labor..Like i said ive heard the noise it makes and it does sound bad,But only when its starveing for fuel.I had 41lbs before i changed the fuel pump now i have 42lbs just turning the key to on -not cranking.The Haynes manual shows that i am within specs.of 41lbs -47lbs..So it only runs while the starting fluid is being sprayed,and it runs good to ,no noise..and no i havent checked the TPS..The code reader never came up with that ,matter of fact it said pass -no problems! Go figure ..lol.Well keep the suggestions comeing please. Thank you

The injectors have 12v to them they just are not getting the ground signal from the PCM.

If you press the gas to the floor while cranking the PCM cuts the fuel supply. If the throttle position sensor is shorted out it could be sending the 'clear flood mode' to the PCM. Your manual should have a testing procedure. How did you determine the PCM is not grounding the fuel injectors?

im figureing theres no ground signal to the injectors from the PCM or there would be fuel spraying in the cylinders to run.

im figureing theres no ground signal to the injectors from the PCM or there would be fuel spraying in the cylinders to run.

If you've confirmed the fuel injectors are not spraying or being inhibited then you may actually have a Passlock related problem. I did some research and Passlock works like Passkey/VATS. One thing it does is send a pulse width modulated signal to the PCM module to enable the fuel injectors. I'm quite sure the source of the signal is the BCM module since the key cylinder interfaces with that component.

BTW - You may have an ignition switch problem.

yeah i think ill check into the ign.switch,ive pretty much been everywhere else.

You need to find out for certain whether or not the fuel injectors are getting grounded from the PCM. I've used a #194 light bulb to make sure the injectors are being fired.

I wouldn't waste too much time hunting down this so called ground. Based on what he has said so far it appears the injectors are not being pulsed.

Plus accessing the fuel injectors on the GM 3.4L V6 is not easy including hooking up any device such as a test lamp or NOID light. Plus he is hindered by using poor reference materials like a Chiltons or Haynes manual.

On the 3.4L V6, 12 volts is always present at one side of the fuel injector coil when ignition is at run/start. The 12 volts can be checked at the fuse socket for minifuse #48 (engine compartment fuse box) which is the fuel pump/injector fuse. Also, make sure that fuse is good.

The pulse from the injector control line from the PCM for each fuel injector would have to go "low" or as he put it in his terms "ground". At that point the injector does it's thing for that short period of time. At all other times the fuel injector control line is high meaning the injector(s) does not fire.

From what I can see the fuel injector control lines are being inhibited possibly due to the Passlock problem and as seen by his SECURITY light. If he gets this issue resolved then he will be able to see what further internal engine problems he has, if any at all.

This does sound like an ignition switch problem, but I :dunno:.....

Start with some obviuos, Does the key look dirty?
or hav things hanging from it(trinkets) ?
Does the key pull out when in the "on" position?
(these should all be NO ;))

He said the injectors were replaced, were they New or remanufactured/rebuilt?
or were the old ones cleaned ???

You can test the injectors at the harness for the injectors on these 3.4s, not at the injector, because you cant get to them with the niod or really anything.

Just follow the wires from the injectors to the main harness connector, and test with the niod and check voltages at the PINK wire, they should Ohm out between11.4--12.6ohms this is done with the key "on" or while cranking it over. If no power is at the injector then check the feulpump/injector fuse.

Also thiers a ground on the intake for the injection system, if its loose it will cause a no start or make it seem as if thiers more serious problems then their really is. This could hav been overlooked when injector work was done.

A lean fuel mix , or misfire will cause the motor to sound rough, as if something else was wrong.

that is whats funny, he's replaced all that stuff which could hav been tested first :disappoin
I hate throwing $$ at something like that.:shakehead

:angryfire Dont take it personal anyone, the stealership should hav been able to diagnose the problem to a "T" , and tell you whats wrong. :angryfire

hope this all helps procrstinator :)

something I forgot is the crankshaft position sensor, thiers two on the v6.
The 7x is on the firewall side of the motor, the 24x is on the CS behind harmonic balancer(CS Pully).
Check them for broken or loose wires, both can be tested too.

The 7x is a pita to get to, thiers two wires for this one at the ignition control mod a purple and a yello they need to be tested in AC, should be at least 200millivolts when cranking over, if not replace it.
THe 24x on the CS (passengerside), first check for power from the pcm.
Disconnect the plugin, connect the positve on the voltmeter to the red/white wire and the ground to the black wire terminal turn the key on and it should be 12vlts, if not check the wiring from the 24x to the pcm.
To check for operation is a bit moer involved, reconnect the plugin. Using a probe, back probe the light blu/black wire terminal of the CSPS and connect the positve lead of the voltmeter to the probe and the negative to an engine ground. Turn the key on, it should be about 10vlts. Now rotate the engine slowly(by hand) with a breaker bar and socket on the CS bolt, while reading the meter it should read between 10vlts to 0 as the blades pass the interpruter ring passed the CSPS.
If its not with in those tolerances, replce the 24X CS postion sensor.

Yeah, your dealer sounds like a rip off artist just like mine. I knew nothing about this whole VATS / PASSKEY / PASSLOCK issue until I started reading posts last night after being very frustrated and loosing $800 on my 96 Monte Carlo.... Search forum with "96 monte carlo won't start" if your intrested in reading my story.

Yeah, your dealer sounds like a rip off artist just like mine. I knew nothing about this whole VATS / PASSKEY / PASSLOCK issue until I started reading posts last night after being very frustrated and loosing $800 on my 96 Monte Carlo.... Search forum with "96 monte carlo won't start" if your intrested in reading my story.

Interesting story. I agree with one of the posters about using WD40.

The problem is cleaning and lube may only be a temporary cure. The key cylinder/ignition switch should be replaced because it is worn out, otherwise the problem may come back.

Give the dealer hell. Good luck!

Actually WD40 can short out the ignition switch.

They make a special dry lube for eletronics thats best used,
but as BOB said,
replace the Ignition switch and it should fix the problem the right way.

Good Luck