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laimisl wrote:...Is there other method?

You could pull the fuel rail with the injectors attached without disconnecting the fuel lines. You could then set up six containers to catch the gasoline and turn the key to start and observe the spray pattern and measure the quantity of fuel from each injector. You can also watch to see if the injectors drip when the key is turned off.

Forgive me if this has already been discussed in this very very long thread....and, assuming that these things did not change between '95 and '97 (?)....Here is something interesting I came across while reading my '95 factory service manual regarding the fuel system:

95 Factory Service Manual 6E3-C2-5 wrote:
FUEL PUMP ELECTRICAL CIRCUIT
When the key is first turned "ON," the PCM energizes the fuel pump relay for two seconds to build up the fuel pressure quickly. If the engine is not started within two seconds, the PCM shuts the fuel pump "OFF" and waits until the engine is cranked. When the engine is cranked and the RPM signal has been detected by the PCM, the PCM supplies 12 volts to the fuel pump relay to energize the electric in-tank fuel pump.

As a backup system to the fuel pump relay, the fuel pump can also be energized by the fuel pump and engine oil pressure indicator switch. The normally open switch closes when oil pressure reaches about 28 kPa (4psi) . If the fuel pump relay fails, the fuel pump and engine oil pressure indicator switch will close and run the fuel pump.

An inoperative fuel pump relay can result in long cranking times, particularly if the engine is cold.(my highlight)

An inoperative fuel pump would cause a no start condition. A fuel pump which does not provide enough pressure can result in poor performance.

If you can hear the pump run for two seconds when you turn the key to "ON," I would think your relay is okay.

Here is another thing to try the next time it is really cold. Turn the key to "ON," wait until you hear the pump run and stop, then turn the key to "OFF;" wait a couple of seconds, and repeat before you turn the key to "START." This will help to build pressure in a faulty fuel system. If it starts easily then, you may have leaking injectors, bad check valve, or a weak fuel pump. I have a leaking injector on my '95 and that procedure really helped it to start more easily on really cold days or after it had been sitting for several days.

Hi everybody.

Hope you are having great summer.

I have just noticed that my outside temperature of that is shown inside of the car was blinking for a while and then it came back again to be ok. Coil this be the little issue that causes hard starts in the cold days east north of winter? I have seen that happen few times in the past and during wet days of winter.

Could that be wrongful data between outside temp and the temp of the coolant be of a problem?

As now it is summer it starts ok and easy and most of the times it starts from half a turn.

Yes my relay of fuel pump is ok and gives a sound of few seconds just as you described Bill.

Awaiting comments for the outside temp blinking issue.

Thanks, Larry

I don't know if the outside temperature sender for the climate control would have any effect on the "hard start cold" issues you have been experiencing. If I had to guess, I would say it is not likely. I hope someone will correct me if I am wrong.

It is my understanding that the PCM uses other sensors (intake air temperature, and coolant temperature sensors) for temperature inputs to adjust the fuel-air mixture for cold start.

I agree with Bill. My understanding is that the outside air temperature sensor is used exclusively for the climate control. The flashing indicates a problem in that system, often associated with a broken actuator. Yours may be flashing due to the temperature sensor. Some vehicles allow you to pull the codes out of that system, without a scanner. I don't believe that yours is one of them. You'll have to take it somewhere to have them scan it for you.

Thank you Bill and Archon for quick replies.

I have scanned the car numerous times, no codes found as well as no check engine is on.

Question, what is actuator and where is it for the climate control sensor?

Thanks,
Larry

Bill, could the failure of engine oil pressure indicator switch be the problem for the hard starts when cold?

Thanks,
Larry

Don't know when Bill may pop back in, so I'll answer for him. The oil pressure switch will not affect the starting. If it's a sensor, it will be one that controls things like air, fuel, or spark.

This is a thread where a member had a similar problem as yours. The scanner used must be one that can read the codes of the climate control system. Not all of them can.
http://www.pontiacbonnevilleclub.com/fo ... =19&t=7013

Thanks for the assist, Dick. Enjoyed a beautiful day today at the lake.

Always happy to lend a helping hand.

Hi all,

Hope summer is nice where you are.

Just today I had this funny occurrence as described in viewtopic.php?f=19&t=12515 thread.

But in my case the SECURITY light was on and I could not turn engine on.It even I think, did not let the fuel pump to make the click noise in 2 secs about, and surely it did not let the starter to turn.

This happened as I left my car with open windows but closed doors and locks.

After this happened and I could not start I just made sure ignition lock is off (even without the key, you see I notice that the lock is used a bit, and sometimes I have power and lights inside even if the key is out, which is not standard, and if I juggle the ignition it locks and all lights shut off if the key is not there and the door is open) then I closed the car with remote and opened so on and off few times.

After that I tried to start and it started just fine.

Do you think that is ignition lock and/or key problem or can this be crank sensor that is also the problem during cold winter days? Where to locate that crank sensor and how to test it.

Thanks,
Larry

A bad crank sensor can cause a no-start condition without setting the check engine light. They can also become temperature sensitive; however, the typical symptom in that case is that the engine cranks but will not start when hot, but will start when cold. But, at this point, I don't think your case is typical, so I would not rule out a bad crank sensor.

The security light staying on when it should be off indicates a problem with the vehicle anti-theft system (VATS). The contacts for the VATS resistor are connected to the ignition lock cylinder. So, if the key is dirty or the cylinder is worn, that may explain the no-crank issue you had recently. This would seem to be a separate problem from the no-start-cold problem as, in that case, the starter does work.

A bad ignition switch can cause a crank but no-start, or random stall condition. The ignition switch is actuated by a long rod connected to the lock cylinder, and is located towards the top of the steering column under the dash.

I believe you can check the ignition switch with a test light at the pink wire entering the ignition control module. Be aware that checking for 12V on the pink wire with a multi-meter will not always reveal a bad ignition switch. The switch can wear in such a way that a small amount of current can pass and indicate 12V on a multi-meter, but not pass enough current to properly operate the ignition control module. I use a test light made with a brake light bulb. If the switch will pass enough current to light the brake light bulb, it will pass enough current to operate the ignition. A good ignition switch will light the test light every time when the key is in the start or run position.

To check the crank sensor, unplug one of the connectors to a fuel injector, then bend out and insert the metal contact wires from a small 12V 194 bulb into the injector connector. If the bulb lights repeatedly as you are cranking the engine, I think that indicates that the crank sensor and ICM are all doing their job.

The crank sensor is located behind the big crankshaft pulley (harmonic balancer - HB) at the bottom of the engine. You must remove the big bolt on the HB, either with an impact wrench or with large hand tools by immobilizing the crankshaft by holding the flex plate. Then you need to remove the HB with a puller designed for that work, then unsnap a plastic cover, then disconnect and unbolt the sensor. They cost about $35.

I am not positive that the above tests are foolproof, so I hope someone will correct me, if I am wrong.

Hi,

Thanks for the tips. I will check on that.

One more thing happened just few days ago when it was raining very hard and it was probably 100% humidity.

The car was on a little slope.

It started ok, but when I parked it on the slope, and tried to start it, I wanted to start it fast, meaning I did not wait for the fuel pump to make a click sound, so I tried tostart and it started with 100RPMs and then died , this lasted few tries and all of them failed, until I turned ignition off, and then on, and waited for the click sud of the fuel pump (or pressure) and then it started ok. I revved it up and it was fine. But it felt like the mixture was too rich once I have started it.

Any ideas what that may resemble to?

Thanks
Larry

Forgive me for not going back to re-read all 8 pages of this thread, Larry, but it will be quicker just to ask (perhaps again): Have you checked the fuel pressure under various conditions to determine whether you have low pressure, a leaking check valve, leaking injector, bad FPR, or other problem that might explain these poor starting issues?

Edit: I just did read all 8 pages of this thread, and unless I missed it, you have not checked injector function during a cold, no-start condition. And, again, unless I missed it, you have not checked the fuel pressure. Low fuel pressure, or leaking or weak injectors may be causing the hard cold start. I am thinking it is time to take a look at these items.

Thanks Bil,

Appreciate that.

I read many other threads.

I understand that fuel pressure should read 37 PSI running 45 PSI key on engine off. Or similar.

To test that I need to buy a fuel pressure tester. Also the AC pressure tester would do, I will see what I can find, I am short with tools.

But I prefer to do it all myself.

I also read this ""If it cranks, but won't start, check the fuel pressure regulator on the fuel rail. Pull the vacuum line off from it, and check for fuel, or the smell of fuel. If you find any, replace the fuel pressure regulator, but don't drive the car. An errant spark can destroy the upper intake manifold and start a fire. If that's fine, check the fuel pressure. Then, we can move on from there, if no problems are found.""

So how the FPR looks like? Sorry to annoy you, I just do not have any idea how it looks like.

I am going out to look under the hood for something similar. And also gonna to check for pressure on the fuel rail at the schrader valve. Is that schrader valve similar to valve stem at the tire?

Thanks,
Larry

PS will be back in few minutes.

Here is an update:

The engine was running normally.

I assume this is FPR:
http://i601.photobucket.com/albums/tt98 ... CN5115.jpg


After I shut the engine down and removed the FPR vacuum line and sniffed it, it did not leak gas, and it was not wet with gas, it was dry. It smelled gas just very very little. I guess it should smell little bit as on the other side of diaphragm there is gas and the gas smell permeates through.
http://i601.photobucket.com/albums/tt98 ... CN5117.jpg


Then I waited less then 30 minutes, and then checked for pressure on the fuel rail at the schrader valve.
http://i601.photobucket.com/albums/tt98 ... CN5116.jpg

As it was mentioned in the thread there should be about 40+ psi of pressure when you depress the valve stem with a small screwdriver. So I pressed the Schraeder valve and just a little weak stream of gasoline went out.

As one of you mentioned "If there is little or no pressure on the fuel rail, and the oil still smells like gasoline, suspect a leaking injector."

I also smelled the oil dip stick, and yes it smells gasoline. It did smell that before as well, but somehow I assumed that this is the way it should be.

Now I have just few questions:

1. If the fuel injector or injectors leak, could there be anyway FPR diaphragm broken? And now as all pressure leaks through the injectors and there is no big pressure the FPR vacuum line it is not wet.

2. Is FPR assembled with a fuel railing as one unit or it can be disconnected and changed: http://i601.photobucket.com/albums/tt98 ... RailDS.jpg


3. What is that Hexagon screw on the top of FPR, also there is extensible ring that shows top of it can be removed, can I change parts inside of it?
http://i601.photobucket.com/albums/tt98 ... CN5114.jpg


4. I understand that to remove the injectors I need to remove few screws (4 in total) for each fuel railing, and then to twist and pull the injectors out, of course by removing electrical heads first.

5. Which injector is bad, how to know, could I test it with the pressure, or some testing equipment of some sort? Do you know if it is recommended to use rebuilt injectors? I know for diesel they do rebuild them, may this be the same?

Thank you for you input, I really hope this is the end of it all, so much time for this, but good thing is I am learning so much of new and interesting stuff and something I like.

Larry

PS After we are done with this, we have to tackle SECURITY issue with VATS system, as I dammit had this problem again just before testing for fuel pressure :-). After this car will be like new!

Larry, the FPR has a snap ring that you compress and remove. You can then pull the FPR out and install the new one. Don't know what the security torx screw is for on the top.

Somewhere back a few pages in this very thread, you will find a procedure that I described for you explaining how to check for a leaking injector.

Thank you very much Bill,

I have tried to fit the AC manometer on the schraeder valve to see what pressure ot gives, but that thread was different, so I will need to look for exact fuel pressure gauge.

Yes Bill, I went through all the thread in detail and reread all you advises how to search for the bad injector.

I also started to shop for the new injectors, and now considering weather I should go with rebuilt ones or not. Could you advise if that is worth? There is injectorwarehouse.com that offer all 6 for 150 rebuolt with 2 year or 24k miles warranty, same warranty the new injectors come with.

Since me vehicle has 320k km, it would be the time to change all of them. Dont you think?

And please remind me (not sure if it was mentioned in this thread) how to change the injectors. What I think, is that on each of the sides I loosen 4 bolts that hold fuel railing and then remove electro connectors, and from the web new injector pictures I did not see any threads on them, so the would just pop out and new would pop in. Please confirm.

Of course I expect to re-leave the pressure via fuel pressure gauge schraeder valve.

Also Bill do you think I need to replace FPR as it is dry and not really smelling lots of gasoline?

Thanks,
Larry

The Techinfo thread: Change Upper Intake Manifold & Lower Intake Manifold Gaskets provides detail with photos on how to change the injectors, but does not discuss testing them.

I would first check the flow pattern and whether they shut completely off (no dripping) with the fuel injectors still connected to the rail as described on the top of this page of this thread to see if, indeed, I had a bad injector. If so, it is up to you whether to change all, or just the bad one(s). If it were me, I suppose I would probably opt for just changing out the bad one. It is not that difficult and you don't have to dig down into the engine to get to them.

Some folks like to change everything to eliminate the possibility that any of the new parts will soon fail. Sometimes that makes sense, other times, not. I usually cannot afford to replace everything that might fail in the future. So, if it were not leaking, and if it was working properly (fuel pressure increases properly as vacuum is applied), I would not change the FPR.

In your case, I would say your money may be better spent on a Harbor Freight or other low-cost fuel pressure test kit. This will tell you whether you have a weak fuel pump, a good FPR, and also quantify any pressure loss caused by a leaking injector or bad fuel pump check valve.

Thanks for reply Bill.

Here some fresh info.

Got the fuel pressure gauge-meter.

Just before starting the car pressed the shrader valve - nothing came out, not a whiz, just little flow with no pressure.

Then hooked the pressure meter on, showed no pressure.

Started the car-engine. Pressure showed to be between 29 and 30 PSI., revved the engine up, the PSI dropped to abt 26.

As it idles, it shows between 29 to 30 lets say 29.5 PSI.

As I stopped it this what it showed as time passed:

after 10 mins - 28PSI
after another 5 - abt 27PSI
after another 7 - 25 PSI
after another 4 - 24PSI

So do you confirm this is the injectors fault?

I have lubed with oil the fasteners of fuel railings, and also I think I need to remove one short fastener that keeps alternator secures to the engine, do you agree Bill? Is anything special there? With that alternator rod?

Then as the railing will be loose to be removed should I disconnect the injectors from it or pull the whole thing out?

As I will be installing, should I install each injector and only then the fuel railing?

I am about to change all 6 injectors as all 6 refurbished comes with 2 year warranty and 24k mile guarantee, and I have no time to test the old ones, and also all 6 re manufactured cost 150$.

Also the from 3 injectors are rusted on the metal side of theirs. So not much saving there.

I would not like to replace so much, but the price is good, and I just got a newborn, so do not have so much time to do all tests, I would like to fix this and hope it will last me another 5 years.

Awaiting for your comments as I need to roll on this and get it over with. Thank you.

Thanks,
Larry

Bill's taking a short vacation so we'll be filling in for him while he's gone. By the instructions, it looks as if the only things you'll have to remove to get at the fuel rail is the spark plug wires that run over the top of the intake, and maybe some cable clips that attach the wiring harness to the fuel rail.

Your fuel pressure readings are low. Did you bleed the air out using the valve on the tester? Turn the key on and off about 3 times. The normal reading is between 48 & 55 psi, and over a 10 minute period it should not drop more than 5 psi. Your pressure seems to be holding well, but the test may not be all that accurate due to the low pressure. If you haven't already, start by replacing the fuel filter to see if pressure increases. At idle, does the pressure increase if you pull the vacuum hose off from the fuel pressure regulator?

I'd suggest pulling the rail with all of the injectors attached, then working on them from there. Clean the area around the injectors well, with compressed air if you have it, to keep dirt from falling into the holes when the rail is removed.

If you are driving the car, do so carefully. Hard or WOT throttle runs with low fuel pressure can cause some serious damage to the engine due to a lean condition.