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1995 Buick regal custom 3.8 no spark

my 1995 buick regal does not have a spark, and I have had 2 mechanics look at it. The sereptine belt broke while I was driving, I believe it was because the water pump was bad and locked up. the belt got wrapped up in the crank pulley and I removed it. The AC has not worked in a really long time so I do not think that it is that pulley. It is not getting a spark. I have replaced the water pump, and the car sounds like it wants to start but it is getting no spark to it. I have had the crank sensor tested and the coil something. none of those seems to be the problem. some one suggested that it is the computer brain. I suggested that it was the timing. Though I do not really know. the battery is good so i know it is not that. and it has fuel. and i know that the engine is getting fuel. I know that the spark plugs are not getting spark (tested with a screwdriver in the socket on metal) So I have no idea what is wrong with it. Please help

The no-start problem might be caused from a faulty ignition control module.


Two different mechanics were unable to diagnose a missing spark?
You’ve had the crank sesnsor and the coil [pack?] tested?

Did you bring the car in and tell the mechanics what to check, or did you bring the car in and say “it won’t start, I think I might have no spark, please diagnose it”?

I mean no disrespect, but while there are a number of possible causes, a missing spark should be easy for any mechanic to diagnose. I’m feeling like sommething is missing from the explanation.

Is the Security light on the dash blinking??

I think I’d be replacing the crank sensor anyway. Broken belt could have wrapped it good and they weren’t that good to begin with. I took mine in to a shop too to look at the crank sensor. Said no problem but 30 miles later it came apart. So I just might question the mechanic. But like said should be easy to find the problem.

My first suspicion was the crank sensor. Good chance they didn’t understand how to test it.

I know that the spark plugs are not getting spark (tested with a screwdriver in the socket on metal)

This is a REALLY BAD idea on a modern ignition. Good way to fry the module and coils.

Did any mechanic actually test for a signal from the crank/cam sensors? And that engine will toss the timing chain when the plastic cam gear wears. Also, when the timing chain wears iron dust accumulates on the relucter causing a loss of the cam angle sensor.

The coil was replaced and it still wont start I know that it has no spark and the mechanic who has it is my friend and knows that it wont spark also, the crank/cam sensors were tested and still no results. The plugs and wires are new I replaced them my self. I do not know about the module I will have to call and ask him if he checked that, also I asked him if he checked the reluctor wheel on the crank pulley but he has not gotten back to me yet, those are the only two things that I am unsure of at this moment. I have also asked him about the timing chain but at this point I think that he is trying not to take the engine apart too much. I was also wondering if it could be the computer that is messing up…

No offense intended towards your friend, but it is hard to believe a mechanic can’t figure out why there’s no spark.

If that’s just a regular coil, put a 12V test light (a simple small bulb between it and ground) on the primary and try to crank it. If you have a volt meter, you may see a fluctuating reading when it cranks but most multimeters are not very responsive so you could see a lower reading just by virtue of you cranking.
You should see pulsed 12V so a quickly flickering bulb. If you don’t, it is before the coil somewhere.

Maybe the timing belt/chain jumped and the timing is totally hosed? He should be able to determine whether its basic timing is correct by setting the mark on the pulley (I take it is has one) and checking for top dead center on the correct cylinder. Not too much should have to come apart for that, I think.

Reading between the lines here leads me to believe that the car has not been diagnosed or repaired because the owner wishes to have an absolute assurance that the diagnosis is pinpoint and certain and the total price unequivocal. Of course, that is often impossible and shops often play at cat and mouse games to get the customer’s committal to repair the car as they see fit when they actually get started. I would never open that can of worms if the customer expected me to deliver the car back in proper running condition, limiting my bill to the price of parts and labor for my initial ‘from the hip’ guess as to why it failed to run. Could a shop be certain that the car could be made road ready for $2,500? I wouldn’t stick my neck out on that premise.

There’s an inexpensive gadget available, a better, safer way to test for spark at the spark plug. Ask your auto-part store for advice. Harbor Freight has this gadget too I think.

Here’s how to approach it maybe. The spark is produced by something in the engine called the “igniter”. The igniter has 2 inputs: 12 volts, and a timing signal. It has one output: The spark. The igniter circuit might be one part, or a bunch of parts distributed here and there, but it consists of a coil, and a way to interupt the 12 volt input to the coil, and a way to get the spark to the spark plug. ( The current interuption is what produces the high voltage spark, and it has to be timed correctly to the compression stroke.)

To get a spark then, you need battery voltage to the igniter. And you need the timing signal input to the igniter. And you need a connection from the spark output to the spark plug. And you need a properly operating igniter.

A good mechanic will step through these one by one to find what exactly is amiss.

Your friend/mechanic replaced the coil? Just one or all 3?

Unless you’re using a labscope or a digital storage oscilloscope to test the crank sensor just replace it. This requires removing the crankshaft pulley with a special tool. Any testing you do with a plain old voltmeter will be useless.

Are the fuel injectors pulsing?

witch pully did the belt wrap it shelf around if it was the crank pull it could have broke or damaged the fines on the back side of the dampner witch the crank sensor uses. the dampler is sold at most auto part stores for about 90.00.