My chevrolet lumina Z34 have been acting weird recently.
It is an intermittent problem. I have been have problem with the car when the temperature is below +5 in the past weeks. Id say 1 time out of 4, the car wont start, and then when I try again 6-7 hours after, it star without any difficulty.

Also, I take the car in the morning when the temperature is cold and it is working fine, but then in the after noon, it wont start. There is also no relation with the humidity outside and the fact that it wont start.

I really dont have any lead. What I can tell you is that when the car dont start, it is doing a normal noise of a motor that is trying to start, but dont succeed in doing it.

A month ago, the car wouldn't start at all so I had the electric cables changed and candle....it did work for about a week.

Please help me!!!

thanks, Phil Bern

sorry for my english :banghead:

DO you have Check Engine Light? You can pull the codes easily:
www.avigex.ca/xport/readingcodes.jpg
Most common cause with these symptoms is crank position sensor gone haywire....
www.avigex.ca/z34/cps34.jpg
or ignition module
www.avigex.ca/z34/ign34.jpg

Take a loose spark plug with you. When it doesn't start, pull a plug wire off, put the loose plug in the wire, set it on the engine and crank it to see if there's spark or not.

If there is spark, take a can of starting fluid (ether spray) with you, and fire a shot in the intake when it won't start, see if it starts on that.

Then you will know if it's spark, fuel, or both. Each has different implications.

Thanks for your response.

LMP, No I Dont have the Check Engine light on, except when there is slowdown on the highway some time it come on, but shut down when I turn off the motor.

****!! I brought the car to the garage and the guy charged me 400$ to change the starter!! THE CAR IS STILL DOING the same thing! He says that
the sensor are fine and that its not an electric trouble!

Hel^p!

..... What I can tell you is that when the car dont start, it is doing a normal noise of a motor that is trying to start, but dont succeed in doing it......
YOu were right. I had understood the starter cranked normally.
.....I brought the car to the garage and the guy ...says that the sensor are fine and that its not an electric trouble.
Interesting and annoying: how a guy who changes a primitive unit like a starter that already cranks can make difference between a good and a bad sensor...?
Car needs two things: fuel and fire. Test "jeffcoslacker" had indicated is COMPULSORY and you can do it for FREE. (well almost: a can of starting fluid you will have on hand for other occasions anyway) ... From there you will have a lead.
BY the way, enegine also needs air: my son's Z-34 has bad habit --well, occurences-- of flooding ...has to keep throttle pedal to the floor when that happens so it has air to burn the fuel.

EDIT: did you "pull" the codes as I suggested before? you said the CEL comes on from time to time: even with the CEL off, the codes stay stored and this could help. A blocked EGR valve could very well impair starting....however, since the battery has probably been disconnected for changing starter, these stored codes will have vanished....

I had the exact same problem with a 1982 Cavalier Wagon with the 2.8LV6 -- intermittent no start.

Ended up being the fuel pump in the fuel tank.

It was intermittent, but would certainly leave me stuck -- needed a tow several times, and guess what? by then, the car would always start, so that the problem could never be replicated -- the thing about it was that it would never happen if you tried, or at an opportune time or place.

I also had an issue with a non-reputable service center -- they correctly diagnosed the issue, and charged for the replacement of the fuel pump, but never changed the fuel pump. So beware.

The correct way to test this is when the issue occurs -- check the pressure at the Schrader Valve on the fuel rail -- with the key on fuel should come out with some pressure, so use a rag over the opening as you relieve the pressure -- then try cranking some more, if the burst ends up being a little spurt, get the fuel pump changed. Upon Key off/key on you should hear the fuel pump prime for a few seconds then shut off.

add: The CEL never illuminated. The old [stock OEM] pump was returned to me -- the electrical contacts were burned out as if their seals failed causing the pimp to short through the gasoline[?] or maybe from not being immersed in the fuel which cools the pump[?].

So LMP you say that a blocked EGR valve will cause the engine to not start? Because I have the same car: 92 Z34 and took it to get Ignition Module and 2 bad coil packs changed and still won't start. But SES light came on and threw back code for EGR circuit failure. My car used to stall out on me but now it wont start and has been sitting for 3 weeks.

what do you mean by "doesn't start"?
No sound from under the hood or what?
What happened after the starter has been changed?
(BTW, I like these guys - "Let's change that and see. It will cost you $$$". Education at the car owners' expense :) )

I've spent some time this weekend pinpointing the similar problem - there are plenty of opportunities for "not starting", so please, specify.

The code scanner will also help - Pepboys and Advance Autoparts sell it for $120, E-bay guys - just for $40 or even less.

O-ops, I didn't notice that you've already written about the "regular noise". Then check if the sparking plugs are dry, if the spark exists, if the pump buzzes when you turn the ignition key...

So LMP you say that a blocked EGR valve will cause the engine to not start? ... My car used to stall out on me but now it wont start and has been sitting for 3 weeks.
Yes I have had cases (not with the GM 3 valve style EGR though) of EGR valve blocked opened (or partly opened) . IN that case, engine fires a few strokes on starting but then exhaust bursts invade the intake manifold and it will stop right there..unless you throttle it to high rpm at the first sign of life..but then when you let it fall to idle, it stops.
My son Z-34 is not totally "clean", but this is winter and as long as it goes...I 'll wait for spring. One problem is high idle at start..the colder, the faster. Really annoying. returns to normal as soon as warmed up.WIll try some tricks soon...
Other is flooding..had to learn the kid (when that occurs) to keep throttle to the floor to kill the injectors. He got the car for 450$ last spring, so no complaint. Beside that, it's a nice car.