Engine stalling, looses power, then hard to start

Seems the idling speed is too low and I would suggest cleaning the throttle body and IAC and retest. Dirty throttle body and IAC would result in low idling and stalling after warming up.

Hi,
What kind of cleaner shoudl I use? Is there a special kind? Or just a throttle bottle cleaner? Use the same cleaner to clean both?

James

So you would rule out the O2 sensor? The one I replaced was the upstream. I have never replaced the downstream O2 sensor? Should I replace it?

What about the ECT sensor?

James

We won't rule out anything for now. The normal procedure is to start with the basics and cleaning is not going to cost you much. Replacing components could be costly and might not resolve the problem if it is not the cause.

Cleaning the throttle body and IAC only helps and causes no harm. There are aerosol carb cleaners available at parts stores and the best way is to remove the throttle body and separate the IAC from it for cleaning. However if you remove the air hose and use a tooth brush and rag to clean the throttle bore, it works though the IAC cleaning might not be thorough. Point the nozzle into the port at bottom of throttle body to clean the IAC and let it soak for a few minutes. Repeat the process a few times and allow the carb cleaner to evaporate before attempting to start as excessive carb cleaner would result in flooding and difficult starting.

Initially the engine might be difficult to start and satll upon starting but that is to be expected, until the carb cleaner clears off.

The idling speed should increase and it might take some time to settle back. If necessary, repeat the IAC cleaning after running the engine for a few minutes.

Hi,
I did both of the things you mentioned today but have not driventhe car yet.

1- Will error codes still be present even if the check engine light is not on?


2-One thing I noticed is after use the sensor cleaner, I started the Tracker up, and you said it would run rough and it did. The symptoms im having is exactly the roughness and having to give it more gas to keep it going.

*What would be the next things to check for if this did not remedy the situation?

thanks,

James

If trouble codes had been recorded, they would be in memory until they are cleared.

Were the spark plugs checked/replaced?

Try driving around for a while and see if there are any improvement. /you might need to repeat the cleaning process again if the result is not satisfactory.

Should I use a good fule cleaner additive or are they a waste of money?

A while back I had a bad expereience with Berryman's B-12 additive. Are you familiar with it?
After using the additve, about 1 hour later the car did the same thing that it is doing now. Could that have been a result of the fuel additives?

Thanks,

James

I never have a good relationship with additives and don't think they are much of a help, at least that is what I have experienced. You could have bad fuel in the tank and draining and refilling might help.

Ok-
So a few days ago I did the IAC cleaning procedure and changed the fuel filter as well.

TODAY-
The car had been sitting all night, this morning I get up and drive it, about 30 minutes later after driving..I was idling..and it started to do it again...
It seems like it does it on warm or hot days, and it occurs usually while idling..it cuts out. Almost like fuel starvation.

Sometimes I am able to push on the accelerator and keep it going long enough to get it off the road. It is like the engine is starved of gas or a choke feeling which makes the engine stall. At times I have to put it in neutral and push the car off the road...

I usually wait about 30 minutes with the engine off, then start it and drive again..About another 30 minutes or so, it does it again.


The Spark plugs were replaced about 1-2 months ago. I have never replaced the ignition packs (#4 of them)

There is NO Check engine light that is coming on at all-right at the moment. The last time the check engine light came on (About 5 months or so ago) It was the O2 sensor Bank #1 Number #1.

Could there be codes now that indicate a problem even though the check engine light is not coming on?

What should I check next?

Today once thing I did notice is after waiting the 30 minutes for the car to rest, After I started it, the car idles at about 750 RPM..Which is normal according to my manual. I did notice that there a slight hesitation and drop in RPM, Could it be maybe a ignition problem?

What other clues should I be looking for so I can help find the solution?


Thanks James.



COULD IT BE ANY OF THESE THINGS:
*Temp sensor
*Throttle position sensor
*O2 sensor failing again?
*Crank sensor?
*Mass airflow sensor

What about a bad PCV Valve? I replaced it back in 03/24/13.

James

As problem seems to be temperature related, the next thing on the list to check would be the Engine Coolant Temperature sensor. Most sensors would throw error codes and the MIL not indicating does not necessarily mean there are no codes. Some codes requires a 2 trip detection and some don't trigger the M IL.

Check for trouble codes and if possible, monitor the ECT operations.

I took out the Idle Air control Valve and cleaned the end with some throttle body spray. A few questions about the IAC Valve:

1) What is the proper way to test the valve to see if it is working ok?

2) When I re-install the valve, what adjustment do I need to make it to it? Should it be all the was adjusted back in or left out a little?

3) I checked the resistance on both the IAC and TPS and it checked out fine. But how would I know for sure they are working ok?



TPS Questions:
I checked the resistance and it was ok. Is there a way I can clean the TPS? What about adjust it?

2) How would I know if the TPS is ok or broke?

AFTER THESE THINGS:
*What should be next to check?

Thanks,

James

ANOTHER QUESTION:

One thing I think I originally forgot to tell you involves the changing of the fuel pumps. AFTER changing a new fuel pump the issues seem to go away for several months, then reappear again.

I have a friend of mine change the fuel pumps and the little white sock that is attached to the new fuel pump, then it will run fine for a while then act up again.

What could that indicate?

James

Yes, you should be checking the fuel pressure. I missed out the date you replaced the fuel pump and thought it was recent. Fuel pump can go bad but sometimes it is just the hose connecting the fuel pump to the housing that is leaking resulting in pressure losses and difficult starting. This would also reduce engine performance.

The best way to test the TPS and IAC is to use a scan tool to monitor their range while in operations.

You cannot clean the TPS as it is a sealed unit and is a variable device for different resistance at different throttle opening.

As to IAC, you need not adjust it as the engine computer would automatically reset it depending on signals from other sensors.

The thing I mentioned is the frequent changing of fuels pumps. The issues I mentioned seem to go away for several months after a new fuel pump is installed.

Why would this occur?

ALSO:
Im not 100% sure how to check my fuel pump relays. I tried using a VOM for example the Haynes book says the resistance between terminal C + D should be according to the haynes book (63-77 Ohm's) When I check it im getting 90-92 Ohm's.

There are three relays I saw that are the same exact ones (GM 30013237) when I tested all 3 im getting 90-92 Ohm's..Am I testing it wrong to get these values?


FUEL PUMP REGULATOR:
*Could this be a issue with the symptoms im describing to you since we started?

Thanks,

James

If you test the fuel pump pressure and regulator, you would be able to find out if they are faulty.

I wonder why your manual mentions testing relays coils for resistance. What you should be testing is if the relay is working and the resistance should be for the main power supply through it.

Ken,
Ok here is what I have done lately. Inside these checkoff list are some basic questions as well to see what I should do.

1) Took off the IAC valve- It was really dirty, Used some carb cleaner on the end of it and inside the IAC (Not on the electrical though)

*How much should the end piece (Pintle) go in and out? When I had my wife start the Tracker, I watched the Pintle move a little at the end, but not a huge movement-

*When I have the IAC Valve removed, how far inside should I spray cleaner into the small hole? Should I use specail cleaner or just carb cleaner for that area?



2) After spraying throttle body cleaner inside the intake throttle area, I left the car for a while for the spray to work. Once I came back I tried starting the car and it would not start at all! When I clicked on the ignition it would not turn on. After waiting a bit longer I was finally able to try and start it, but it would not start as it sounded flooded possibly all the spray I put in?

I ended up having to charge the battery before I could get it started 60 minutes later. Is this normall? The battery is about 3 years old but checks out ok.



3) Once started I noticed these things, that may hel pinpoint the potential issues-

*With the engine running I unplugged the IAC Valve harness...I did not notice much of a difference with it plugged in or not plugged in- Could the IAC be the problem?

Is there a better way to check the IAC Valve? What exactly should that end of it be doing? How far in/Out? Movement, ETC.


4) Also with engine running I unplugged the air filter housing and took the air cleaner out, then engine remained running? Is that normal or should it have stalled out?

ONE OTHER SIDE QUESTION:

5) When a fuel pump is changed, should the mechanic replace the little rubber gasket that holds the fuel assembly to the actual tank? The times I have had the pump replaced, the mechanic just -reused that gasket! Could that be part of the problem?

Thanks,

James

Ken,
Should I load another donation since this is a long process with questions?

Thanks,

James

Ken,
Ok here is what I have done lately. Inside these checkoff list are some basic questions as well to see what I should do.

1) Took off the IAC valve- It was really dirty, Used some carb cleaner on the end of it and inside the IAC (Not on the electrical though)

*How much should the end piece (Pintle) go in and out? When I had my wife start the Tracker, I watched the Pintle move a little at the end, but not a huge movement-

*When I have the IAC Valve removed, how far inside should I spray cleaner into the small hole? Should I use specail cleaner or just carb cleaner for that area?

2) After spraying throttle body cleaner inside the intake throttle area, I left the car for a while for the spray to work. Once I came back I tried starting the car and it would not start at all! When I clicked on the ignition it would not turn on. After waiting a bit longer I was finally able to try and start it, but it would not start as it sounded flooded possibly all the spray I put in?

I ended up having to charge the battery before I could get it started 60 minutes later. Is this normall? The battery is about 3 years old but checks out ok.

3) Once started I noticed these things, that may hel pinpoint the potential issues-

*With the engine running I unplugged the IAC Valve harness...I did not notice much of a difference with it plugged in or not plugged in- Could the IAC be the problem?

Is there a better way to check the IAC Valve? What exactly should that end of it be doing? How far in/Out? Movement, ETC.

4) Also with engine running I unplugged the air filter housing and took the air cleaner out, then engine remained running? Is that normal or should it have stalled out?

ONE OTHER SIDE QUESTION:

5) When a fuel pump is changed, should the mechanic replace the little rubber gasket that holds the fuel assembly to the actual tank? The times I have had the pump replaced, the mechanic just -reused that gasket! Could that be part of the problem?

Thanks,

James

Sorry for the delay in replying. I was away for the past few weeks.

*How much should the end piece (Pintle) go in and out? When I had my wife start the Tracker, I watched the Pintle move a little at the end, but not a huge movement-

Movement of pintle depends on how much it was out previously and engine temperature. It usually moves only slightly.

*When I have the IAC Valve removed, how far inside should I spray cleaner into the small hole? Should I use specail cleaner or just carb cleaner for that area?

Carb cleaner should do.


2) After spraying throttle body cleaner inside the intake throttle area, I left the car for a while for the spray to work. Once I came back I tried starting the car and it would not start at all! When I clicked on the ignition it would not turn on. After waiting a bit longer I was finally able to try and start it, but it would not start as it sounded flooded possibly all the spray I put in?

Yes, after using carb cleaner it would usually require some cranking before it fires up due to flooding.

I ended up having to charge the battery before I could get it started 60 minutes later. Is this normall? The battery is about 3 years old but checks out ok.

Cranking time depends on battery condition/charge and amount of cranking time and if you are able to fully charge it without any starting problem, it should be normal.


*With the engine running I unplugged the IAC Valve harness...I did not notice much of a difference with it plugged in or not plugged in- Could the IAC be the problem?

Since pintle was moving in and out when you tested it, it should be good. Disconnectting the IAC would not make much difference in idling speed as the pintle type would remain where it was at the moment it was disconnected. If you disconnect the wire when engine is cold, rpm would be higher then idling speed.

Is there a better way to check the IAC Valve? What exactly should that end of it be doing? How far in/Out? Movement, ETC.

A scan tool would allow you to actuate the IAC movement

4) Also with engine running I unplugged the air filter housing and took the air cleaner out, then engine remained running? Is that normal or should it have stalled out?

Removing the air cleaner does not affect the engine operations unless the MAF was disconnected.


ONE OTHER SIDE QUESTION:

5) When a fuel pump is changed, should the mechanic replace the little rubber gasket that holds the fuel assembly to the actual tank? The times I have had the pump replaced, the mechanic just -reused that gasket! Could that be part of the problem?

The gasket is only for sealing purposes and if it is not leaking, it should be good.

Hi, Still needing some help, can you help me resolve some more issues with this?

STILL- Having the same issues as mentioned in the above 2 pages.

1- Is there a easy way to check to see if the crank Shaft Sensor may be causing this issue of stalling? Seems to happen when the car starts from a cold start in the AM until it warms up-

Usually if the crank sensor is causing the problem, it would throw a code. However if you have a scan tool plugged in, you can monitor the crank sensor pulse.