[mjsor]

04 Malibu, 4 cylinder, auto.

When trying to start the car may start and run with no issues what so ever.
(OR)
* Starts but dies immediately.
* Starts with key, then immediately dies, and tries to restart/starter automatically engages without turning key.
* Starts but runs at idle/low rpms, runs very slow, like "limp" mode in a diesel truck.

HELP?!?!?!?????

Thanks,

 

[Starship]

Welcome to the forum. If you have the 2.2L, I'd think it's a Malibu or Classic (not LS) which may or may not make a difference. I think your ignition switch is flaky based on "starter automatically engages without turning key." Anything else you can add? Accident and repair history? Current mileage?

 

[mjsor]

Its a Malibu Base model, not an LS or classic, sorry for that mistake. It is a 2.2L purchased new with 85k miles.

It has not been in any accidents or had any repair work that would cause an issue.

It only tries starting itself after it has been started with the key and has died. It seems to turnover until it starts itself then will die and doesn't repeat. Only does this once following me turning the key for the initial start. It doesnt do this ever time. It could be any of the issues I noted. Currently it will not start, only turnover with key but doesnt start.

First thought it may be bad smart key but seems to have issue with either of the two keys.

Thinking:
Fuel Filter
Fuel Pump
Ignition Switch
?????

Any tests that I can do?

 

[Starship]

When you turn the key to ON and wait, what do you see in the instrument cluster? Any indicators blinking or constantly on? What kind of tools (OBD scanner, multimeter) do you own and how familiar with them?

 

[mjsor]

Seems normal... Take a look and tell us what you think.

digital multimeter but do not have a obd meter. No check engine lights are on.

thanks,

 

[chevyguy8893]

The gauge lights run as normal. When the car does start is there a check engine light on or may have been on and went off? It may be a fuel pump issue for the starting and running rough problem, but it seems weird to me that it will run fine once in a while.

I know this sounds weird and it sometimes works, but have someone hit the gas tank with a rubber mallet while someone tries to start the car. Sometimes it jars the pump enough to provide enough fuel pressure to start the car. Sometimes it works and sometimes it doesn't.

As for the vehicle trying to crank without turning the key may be an ignition issue; some have ground issues, programming issues, and even battery terminal issues.

 

[Starship]

It'd be so much easier if you can scan for BCM codes. The fuel pump should prime (distinct whirring sound) for a couple seconds as soon as the key is turned to ON. If not, the Fuel Pump fuse or relay in the rear compartment fuse block may be blown. Also, this Malibu has the PASS-Key III+ system and thus it can get confused if the key ring has other keys with transponders or even a Speedpass key tag.

One other thing to try is to disconnect the electrical connector from the MAF sensor located at the junction of the air cleaner cover and the duct. If that's the problem, the engine won't run without it very well but it will start.

 

[mjsor]

Well we took the car to the local shop. They have the Snap On OBD tool. At the moment the fuel pump is working properly, electrically and pressure. The only issue that we can see is the fuel injectors are not working all the time. When the injectors are pulsing the car will start and run. When the injectors stop pulsing the car will stop running or not start. At the moment we do not know why they start and stop pulsing/working.

Sounds electrical to me, maybe computer related???
Thoughts??
Thanks!

 

[Starship]

Turning the key to ON or START sends a voltage signal each to the BCM. The BCM then energizes the RUN/CRANK Ignition relay. Battery voltage to the injectors come from the RUN/CRANK Ignition relay and then through the Fuel Injectors fuse, both in the engine compartment fuse block. The PCM then fires off each injector by grounding the ground side of the injector wiring. PCM needs input from both MAF and CMP sensors to calculate injector pulses. Anything missing in this whole series of events can produce the symptom you're describing.

 

[mjsor]

Since we needed the car drivable asap, we took it to the local shop. They said they found two issue:

1.) Car would start or not.
2.) When car was running it would (sometimes) run rough. I hadnt noticed this...

They said that the running rough was due to the CMP (camshaft position sensor). This again isnt something that I had noticed. It seemed to run or not and when it ran it ran ok. When it was having issues, meaning, it was not running or would start and die, it would run rough. This is the only time I can remember it running rough.

As for the main issue of not starting etc., they couldnt find a definite issue. They told us that it wouldnt start 5 different times and they noticed that if they touched the fuel pump relay in the rear fuse panel it would start. They could have one technican turning the key while another put his finger on the relay. When he touched it the car would start. From this they suggested we replace the entire fuse panel in the rear of the car. They said it was a connection issue. I ask them to test the relay while the car was running. With the car running we saw 13-14V on the relay pin that powers the fuel pump. As we were doing this the car slowly sputtered and quiet running. A couple seconds later the relay went to 0Vdc. So this tells me that the fuel pump would be the issue but they tell us that when its doing this you can just touch the relay and it will start running again.

This is the most confusing thing ever!!! Wondering if anyone has seen anything like this! We payed for their time and the Camshaft sensor today. This gives us a bit more time to see if the issue arises again.

 

[Starship]

If you're able, you can try a new relay and/or take the fuse panel off and reseat the connectors on the back, I guess.

 

[mjsor]

That was our thought... Unless there was a known, common issue with the panel. That would seem odd that the panel is causing the issue.

We will disassemble and clean/reassemble and update later.

Thanks,