Running great then dies(03 Navig. continued)

[Shad]

It has done this twice now…

Common issue is running well, idles down, runs well, begins to run less well, push the gas, it dies, won’t start.

I have spark, fuel pressure 39lbs, checked the inertia switch circuit around 10 volts, changed brake switch, checked relays and fuses, checked connections to injectors and coils. Now cleaning the MAF sensor, left fuel gauge on for ten minutes it held pressure.

Any ideas

Topic

[Hikaru]

Have you check the ignition coil and capacitor or the cdi?
I was have the same problem, idle and shut when I put the gas, I replace the distributor (coil, cdi and capacitor), it runs fine until now.

[EricTheCarGuy]

If fuel pressure is good during the time the problem occurs then perhaps look to the ignition system. I’m not saying you should replace the distributor but it’s probably worth looking into if you’re loosing spark when the engine stalls.

Good luck and keep us posted.

[Shad]

So if I can get it started again, leave the fuel gauge hooked up to see if pressure stays when it stalls out?

[Shad]

Ok I received my service manual today.

My fuel pressure is within tolerance.

THE ENGINE SEEMS TO RUN PERFECTLY WHEN I CAN GET IT STARTED

Let’s do it again, new plan of attack

I will first drain the gas, put fresh, check the plugs and coils this vehicle does not have a distributor…but I don’t know if that means there is no ignition coil( I am a rookie)

this time I guess I will check the injectors, U do this by listening to them?

And my inertia switch, which if I understand it correctly when it is released it applies pressure to the contact to open the circuit, it then has a reset button which is spring loaded and allows the switch to recoil allowing for the circuit to close is that correct?

I do have an exhaust gasket that is missing but I have the manifold mated to the block incase that might have something to do with the no start.

I feel like I am sooo close but I am failing to do something small

Also a friend of mine told me a story of a truck that had a sensor that was bad and wouldn’t let it run, what kind of sensor would that be?

Thanks for any help, you might be able to give

[Erin]

No distributor – if it doesn’t have one, then it has coil packs where one or two plugs have a dedicated coil which is usually pretty small.

Draining gas – You probably do not need to do that. The only time that is needed is if a car sits for months with the same gas and even then maybe not. OR if the gas got seriously contaminated like say the kids put a water hose in the gas tank (they wanted to play “gas station” ).

OK so here is some speculation…
I believe you recently changed the head gaskets yes? I forget what thread you mentioned something about having problems getting the head on but anyways if so…

When you re-installed the intakes, did you use new gaskets AND torque the bolts properly? Some engines you can re-use intake gaskets and some you just need to replace once the intakes are off. Engines are kind of sensitive about intakes. Ask me how I learned that one.

The missing exhaust gasket probably would not cause any real problems running the engine but would allow exhaust to seep by and stink up the cabin when at red lights.

[Shad]

how can I find out which plugs have the coils,all of the coil packs look the same

I did not torque either of the manifolds, I did replace the gaskets, and I did torque the head bolts

Can oil get in the fuel, the reason I ask is when I changed the fuel filter after the clear gas drained out the rest of the stuff was dark, I don’t know how long it had been on thre

[Gary]

Did you check for vacuum leaks after replacing everything? If you have a vacuum leak, unmetered air will be entering the manifold and may cause a lean condition. Of course I’m just speculating here. You’ve covered most of the bases. As for the fuel filter, it sounds like it was dirty if there was some dark stuff in there. Fuel can get into oil but not the other way around usually.

[Shad]

ok, so the vacuum lines are all the of the smaller lines right?
1.one goes to the fuel rail canister,2.one goes to the egr,3&4.two go to a plastic component that fastens to the side of the of the upper intake, 5.one goes to something in front of the steering wheel,6.these are all small colored hoses,7.then there are three black hoses 3/8″ o.d., 8.one goes to the front of the intake on the manifold on one side,9.one on the other side and one to the brake booster

does that sound right?

[Lorrin Barth]

[quote=”learner” post=115918]
Also a friend of mine told me a story of a truck that had a sensor that was bad and wouldn’t let it run, what kind of sensor would that be?

[/quote]

That could be the coolant temperature sensor or the throttle position sensor. Your service manual should contain instructions on how to test them.

[EricTheCarGuy]

Let’s try and keep this simple. Avoid making assumptions. When it’s not starting, check for fuel psi and spark. You can reasonably conclude that mechanical is OK because it does run when it runs. After you find what’s missing, then pursue that system further. I outline how to do these checks in this article.

http://www.ericthecarguy.com/faq/solving-automotive-no-start-problems

One step at a time will get you there. Keep us posted.

[Shad]

So I have removed the plugs which are very black on the spark end, especially on the right cylinder bank ( how do you determine right and left, looking at the car or like you are sitting in the drivers seat?)

Found 3 bare spots on the ignition harness 1 on cylinder 5 and to on cylinder 7. I cleaned and insulated with high voltage silicone tape.

I checked each of the coils for spark, some seemed weaker than others so to eliminate variables I took one coil that I considered to be strong and interchanged it within the harness.
Result: I have the ability to deliver spark to the plugs at every cylinder.

Tomorrow I will check each of the coils to determine if any fail to deliver a strong spark.

I shouldn’t/can’t determine voltage at the end of the coil?

[EricTheCarGuy]

The damaged wiring is suspect. It could be causing increased resistance and keeping the coils from working properly. In addition to fixing the insulation, you should also make sure the wiring is intact.

There are spark testers that measure KV output.

http://www.jbtoolsales.com/lisle-50850-ignition-spark-tester/#oid=1002_1

I would think with that system you should have at least 40KV.

That said, if you have spark, then the problem may be in fuel delivery. For that you’ll need to do a fuel pressure test for starters. You may be able to rent a fuel pressure test kit from your local auto parts store.

Keep us posted.

[Shad]

I have steady fuel pressure 36lbs.( the service manual specs.@30-45)

I guess I should mention it has COP ignition system, I didn’t realize that there were more than one type.

I read that the crank sensor sends info to the PCM which in turn sends signal to coils and to injectors. Is that correct?

I gapped the plugs though I have seen a couple of your videos where you tell that it is unnecessary most of the time and the story of dropping the plug in the hole and damaging it, so I tried not to do that, thanks. They varied from .042 to .054

I will order the tester, where would I find the actual desired output of the coil if I wanted to know?

will my service manual have spec voltage for the coil connectors on the harness? It is PDF and I haven’t quite mastered navigating yet

I have recently checked out a couple of the FATR episodes, I enjoyed , will be checking out more in the future….You have a pretty cool gig!!

[Erin]

It sounds like so far you have done a lot of work. One thing – you DID make sure everything was at least connected yes? One time I was freaking out that my car would not start after doing something, I did all this testing, sweating etc… turns out I had forgot to reconnect the plug to the ignition coil pack. 😳 Yeah umm, it started right up after. I think the car actually laughed at me.

Here is another speculation, just to eliminate as a possibility…

Another thing to check also would be the resistance of the fuel injectors and no you should not have to remove them to test this.
Just disconnect each plug and carefully put the leads of your multimeter across them.
You will have to find out what the resistance should be, normally it is low double digits but get the facts.

I just say this cause one time I had this Cavalier that would not start easy but was alright once running, turns out fuel injectors were bad. This happened because it was out of gas and I tried to start it pretty aggressively. Well, the gas gauge said I had gas, turns out it was messed up (typical of older J-bodies) Gas lubricated the injectors.

For testing sparkat each wire, the quick and dirty billy-bob way to do that is find a bare piece of metal under the hood (NOT something for the fuel system, best if it is something like the body with exposed metal or a bolt) and situate the plug wire real close to it. As you crank the engine, you will hear it click as the spark jumps. Or if someone can crank the engine while you watch… but, do NOT touch the wire while doing so. It will feel like someone is using the wire to beat your hand. All this does it verify there IS spark, it does not give the voltage.

[Shad]

Cars sure can be difficult and frustrating and at this point Ican only imagine the rewarding feeling you guys get when you solve the puzzle. I have had to work a bit extra the last two weeks so Ihaven’t had time to work on the navigator. There are still some questions from earlier posts that I haven’t answered yet if you would like to check them out…Thanks for all of your help so far, I will keep you posted

[Author]

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