97 Deville No Start

[BodybyFisher]

Based on your previous reading, 1.55 Kohms that is 1550 ohms, so it appears that your CAM sensor is ok.

Based on what you find, Ill post more

[JimD]

Does anyone know what the resistance range should be for the Cam Sensor and Crank sensor(s) on a 97 Northstar?

What is the problem or symptoms? What exactly are you trying to correct?

Does the engine run at all?

[BodybyFisher]

Jim here is his main thread

http://caddyinfo.ipbhost.com/index.php?sho...c=18599&hl=

Both threads were merged at this point

[Ronniels]

Lets check the Ignition Control Module (ICM).

The ignition control module has three connectors, C3 (pnk) is hot all the time with 12 volts from Fuse DISTR.

C1 is the crank sensors (purple and yellow is CKP 'A' & blk/wht and blu/wht is CKP 'B'),

C2 is the CAM sensor (brn/wht and pnk/blk)

Disconnect C2, using a DVM measure the resistance between terminals A and B of IC module connector C2 (harness) side (here is what you were looking for) the resistance should be between 800 and 2100 ohms.

Individually measure the resistance to GROUND at both terminal A and B of module connector C2, the resistance should be AT or below 100 ohms

Let me know what you find, ill post more later.

C2 Harness Side 1250 Ohms (brown to pink wire) Module Side of C2 plug Individual Pin to ground is -46 Ohms and -52 Ohms

Now if I check the individual resistance to ground on the harness side it is not registering at all. So I wasn't sure which side to check to ground, so I did both.

[BodybyFisher]

C2 Harness Side 1250 Ohms (brown to pink wire) Module Side of C2 plug Individual Pin to ground is -46 Ohms and -52 Ohms

Now if I check the individual resistance to ground on the harness side it is not registering at all. So I wasn't sure which side to check to ground, so I did both.

C2 Harness Side 1250 Ohms (brown to pink wire), this means your CAM sensor is good

Module Side of C2 plug Individual Pin to ground is -46 Ohms and -52 Ohms, this is still a test of the CAM sensor correct?, you are testing the harness side right?, this needs to be less than 100 ohms which it appears it is, I believe they are testing if the CAM sensor is shorted to ground here. As long as its less than 100 ohms you are ok.

Did you check for power at C3 with the key on?, check that. You will probably have power as you say you have spark.

We need a way to check the crank sensors but for some reason, the FSM jumps OVER crank sensor testing, I'll keep looking to see what I can find.

Have you tried to start it now that you got all of the moisture out of the cyliners?

Did you check each coil for spark?

Can you get your hands on a new ICM? See this link for ICM symptoms:

http://forums.corvetteforum.com/showthread.php?t=2083818

[BodybyFisher]

My ICM was replaced in April 2003 by the prior owner and the receipt states the symptom as 'rough running cold'. They replaced the ignition module ($619). Now there appear to be many failure modes of the ICM (see Corvette link I posted above). In an earlier post you stated that it seems 'out of time'. Maybe its possible that the coil drivers for half your coils are damaged and that is why you don't start. If I were you, I would get an ICM from a scrap yard at this point and swap it in.

If you can determine that the 94 ICM is the same as the 97 ICM, Regis has one with coils for sale, but check out the compatibility. The ICM is not easily checked without special equipment and you have a no start condition, which is one of the failure modes of a bad ICM.

I found this regarding crank sensors

What are the symptoms of a bad crankshaft position sensor?

Answer:

NO spark and no fuel pulse at injectors. If both go off together then its the CPS.

Engine will stall when stopped, will stall when going along highway but usually start again because of speed. Sometimes will be hard to start, but will start after a couple of times of turning key off and starting again.

[Ronniels]

The -46 and -52 readings are from the ICM side, but the harness side, individually (C2) resistance to ground I can get no reading at all on any setting.

I found an ICM with coils on EBAY, just bought so should have that in a couple of days. If this is not my prob, can always resell the new one. Same with the replacement PCM, will just resell that as well.

Have not reinstalled plugs yet, was letting it dry as long as possible while checking the electrical items. With the ICM un plugged and no plugs it turns over smooth. Which it did not do even with the front four plugs out and the ICM plugged up.

I really appreciate everyone's input.

Thanks!!!

[BodybyFisher]

For future reference, never check the PCM or ICM or electronics side of modules, the simple act of probing can damage sensitive electronics, keep in mind that your volt meter operating in ohm meter mode has a battery inside that pushes a current through the sensitive electronics and can damage it.

I think you would benefit from purchasing a factory service manual (FSM) for your car if you plan to keep it. You can sometimes find them on ebay. Good Luck with this and let us know how this turns out. I hope the one you buy is servicable that will REALLY throw a monkey wrench into this if its not. Mike

[Ronniels]

Is it a problem that when I check resistance to ground for the harness side I am getting no reading?

[BodybyFisher]

Is it a problem that when I check resistance to ground for the harness side I am getting no reading?

No that is good, that means that neither lead on your CAM sensor is shorted to ground, less than 100 ohms is good, you have zero

[Ronniels]

Thanks, well I am still working on drying the cylinders...I just have a 2 gal. portable compressor, so it empties fairly quick and I have two cylinders that are still giving me alot of liquid residue everytime I blow into them. So to keep from wearing the comp. out I am only doing them a couple of times a day. As soon as I get the new ICM in I will re-install the plugs and try it.

Even with all of the carb cleaner, I am certain I smelled str8 gasoline on a couple of the plugs, so hopefully like you mentioned previously. Only 1 bank is out of time and that is throwing off the whoe thing.

I did have someone mention that it was possible that where the previous owners had cranked on it so much, that the starter may be getting fried and pulling too much juice and keeping the spark from being strong enough? Never ran into that myself.

And if the ICM is only parially dead, will that still keep it from even trying to fire? (I am thinking about before they dumped the carb cleaner in) Since that was before I ever saw the car, I can not be for certain how it even sounded turning over then.

Again, the help is greatly appreciated!

[BodybyFisher]

Thanks, well I am still working on drying the cylinders...I just have a 2 gal. portable compressor, so it empties fairly quick and I have two cylinders that are still giving me alot of liquid residue everytime I blow into them. So to keep from wearing the comp. out I am only doing them a couple of times a day. As soon as I get the new ICM in I will re-install the plugs and try it.

Even with all of the carb cleaner, I am certain I smelled str8 gasoline on a couple of the plugs, so hopefully like you mentioned previously. Only 1 bank is out of time and that is throwing off the whoe thing.

I did have someone mention that it was possible that where the previous owners had cranked on it so much, that the starter may be getting fried and pulling too much juice and keeping the spark from being strong enough? Never ran into that myself.

And if the ICM is only parially dead, will that still keep it from even trying to fire? (I am thinking about before they dumped the carb cleaner in) Since that was before I ever saw the car, I can not be for certain how it even sounded turning over then.

Again, the help is greatly appreciated!

In the old days, an engine would not start if the plugs were soaked, it was like throwing a lit match in a buckeet of gas (not that I would ever want to test that theory. I am sure you have had a lawn mower that had a soaked plug. Now I am not sure if that still holds true with the high voltage of todays coils. I am not sure what can happen with the ICM, I just know what I have heard or read, and a no start is one of the symptoms, since you have looked at a lot of other items in your diagnosis, this is an untestable module that we need to get out of the way. The manuals used to say, replace x with a known good x, that is what we are doing here. Because you are not getting an almost start, I don't think the crank sensors are bad, I think I recall the PCM having a 'default' mode if the crank sensor fails, Ill do some reading. Its a shot in the dark but lets get the ICM out of the way. You read that Corvette forum thread right?

With regard to your starter, we can perform a starter draw test at some point, the cables could be melted/burned causing high resistance, turn your lights on and try to start it when you put the plugs back in, how bad do your headlights dim for a quick test.

Do me a favor, take the oil fill off, and look in to see if the lifters move when you turn the starter, at least you can check one bank for its chain or even the main chain. BUT, I think if you did break a chain you would hear noise as they would be interfering badly. According to the guru, the chains are bullet proof and are good for the life of the engine, we don't hear of chains going often.

The other thing that used to happen in the old days is that due to the long cranking, and low oil pressure and possible fuel in the oil, the lifters would not be pumped up impeding adequate fuel mixture flow. Check your oil to see how thin it is and smell it.

Put your battery on charge if you can so its sharp when the ICM comes.

[KHE]

Have you checked for spark at each plug wire? If there is spark, then I would think the ICM was good. "Drying out the cylinders" was mentioned - it sounds like the engine may be flooding. Press and hold the accelerator pedal to the floor while cranking the engine. That puts the ECM into "Clear Flood" mode which turns off the injectors. If it starts, then you need to look for unmetered fuel entering the engine. A leaking fuel pressure regulator or leaking injector(s) are two ways for unmetered fuel to enter the combustion chamber.

[BodybyFisher]

Kevin, this fellow from the prior owner that he poured carburator cleaner into the intake, and flooded the cyliners, I think if that occurred to an extreme the engine could hydrolock, he found the plugs wet. But you are correct about the fpr. He has the old style fuel rail and I advised him not to mess with it until its replaced, otherwise I would suggest he lift it and pressurize it by turning on the key..

[PAUL T]

I still say it is a bad FPR. Just because there is no gas on the vacuum side does not mean that it is not bad. All the symptoms you have point to a bad FPR.

[BodybyFisher]

I still say it is a bad FPR. Just because there is no gas on the vacuum side does not mean that it is not bad. All the symptoms you have point to a bad FPR.

Paul a bad FPR will cause a no start?, do you see the problem as too much fuel here or too little fuel?

[Ranger]

I still say it is a bad FPR. Just because there is no gas on the vacuum side does not mean that it is not bad. All the symptoms you have point to a bad FPR.

The diaphragm inside it is the only thing that can go bad on it. If you want to double check it put a hand held vacuum pump on the vacuum side while you have fuel pressure on the other side. If you still have no fuel on the vacuum side, you can rest assured that it is OK.

[Ronniels]

I am still waiting on the new ICM & Coils, but removed the original to take a pic of something odd... If you look at the last coil post (#6), you will see it is heavily discolored yet the other seven look brand new (in person they do) The inside of all 8 wires are clean though.

OK, scratch that idea...how do I post a photo? The #6 post on the last coil is brown, yet the other 7 are shiny like they just came out of a box... Just thought it was odd...Have a nice photo of it

[BodybyFisher]

I am still waiting on the new ICM & Coils, but removed the original to take a pic of something odd... If you look at the last coil post (#6), you will see it is heavily discolored yet the other seven look brand new (in person they do) The inside of all 8 wires are clean though.

OK, scratch that idea...how do I post a photo? The #6 post on the last coil is brown, yet the other 7 are shiny like they just came out of a box... Just thought it was odd...Have a nice photo of it

It is not likely that one coil would cause a no start condition, but it is something to keep an eye on if you have a misfire or roughness. KenD had a slight mis and someone suggested he look at the coils as you have just done.

Do some research to see if there is any diagnostics for the crank sensors. I am looking forward to see if the ICM fixes this

[KHE]

You need to check the fuel pressure - it needs to be around 45 psi for the engine to fire up. This is the first thing I would do before throwing expensive parts such as coils, ignition modules, etc. at it.

You hear the fuel pump prime - that's good but you have no idea if it is pressurizing the fuel rail with ENOUGH pressure to allow the engine to run.

Do you have spark at each plug? Is it blue? If so, I would not suspect any of the ignition components. The crank sensors on your vintage of car were not a problem.

[Ronniels]

Put the new (used) ICM & Coil Set in the car, and she tried to fire first click!!! (but only for a second or two) But the old plugs sat saturated for so long, they are shot. So went and got some fresh plugs, dropped them in and she ran for a few seconds then died, then restarted, then died. Pulled the plugs back out, 4 of the cylinders are still flinging the stuff they sprayed into it. So I made sure the clean looking ones were definitely dry and put them back in, now back to drying out the other 4 cylinders.

Thanks alot for the advice and input, I know what a pain it is to diagnose something without being with it. My relatives do it to me all of the time.

Just this Deville was kicking my butt since the computer was saying all was good. I do have the original back in the car though. Now will resale the used one. Now she is showing several History codes, but nothing Current.

To show what a gluten for punishment I am...I bought a non-running Northstar with almowst no history about it's condition (the Deville) and just bought a 1993 Olds Conv. with the 3.4 DOHC...this will be my third one of those, if anyone is familiar with them and thier timing belt & oil leak issues, you know the Northstar is somewhat of a cakewalk as long as you keep it maintained in comparison.

But I like challenges, and the Northstar and that 3.4 DOHC are two of the funnest engines (FWD) that I have ever had the joy of driving.

The 3.4 has the original Timing Belt (105k), and it looks a little ragged (just checked it this morning) So there goes a couple of days of fun!

Again, thanks for the help on the Deville. I may have a whole new set of questions after she's running smoothly (fingers crossed), but let's say in this case, my silence is a good thing

[Ronniels]

BTW, the ICM with all four coils, I picked up off of Ebay for $35...so was not too worried if that was not the prob, would have been easy to resale.

[Ranger]

If you have 4 cylinders not firing check the fuses. I am not positive, but if I recall correctly there are two injector fuses. I don't recall if they are for each bank or are devided some other way. just a thought.

[Ronniels]

They are firing, just that the previous owner poured alot of fuel injector cleaner into the intake when he couldn't get it started (bad advice from a good friend I guess) and I am trying to dry them out. Four down, Four to go. So it is slinging onto the plugs when spinning and keeping them from effectively firing.

[JimD]

I would pull all the sparking bolts, hold the throttle valve wide open, and crank the engine for several thirty second bursts.