Toyota Tacoma Stalling at Idle (1997 2.4L auto.)

[Craig]

I have a 1997 Toyota Tacoma 2.4L automatic that stalled on me at a stop sign (3 miles from home; so it was just getting up to regular operating temp).
I have do a LOT of work to fix this issue, and still have not been able to cure the issue. It is better, at least now the stalling is unpredictable, instead of ALL the time.

First, everything that I replaced since the start of the issue:

1. All Spark plugs
2. All Spark Plug wires
3. Distributor Cap and rotor
4. Fuel Filter
5. Fuel Pump
6. Fuel Pressure Regulator
7. Ignition Coil
8. Throttle Position Sensor(tested bad at idle position)
9. Crank Shaft Position Sensor (added this after suggestions in thread)

Cleaned:

1. IAC
2. Throttle Body
3. MAF Sensor

1. Added a can of SeaFoam to the gas tank and a little to the crankcase as well.
2. ODB2 Codes that I have received during this saga.. P0300 multiple misfire and P1300 ignition coil cylinder 1 misfire.
3. I have not pulled the EGR, however, I have pulled the PCV valve hose off (and it dies.. which is what it should do).

[il]Tested the Crankshaft Position Sensor with a multimeter, tested good, so did the wire harness[/il]

Since all of this work, I have been able to get it started and keep an idle, drive it a short distance, then it will stall out and not idle afterwards. Then the next day, without doing anything to it, it will start and run again. Now, Sometimes it Stalls, sometimes it doesn’t. I have been working on this issue for nearly 3 weeks now, with no certain fix.

:sick: THANK YOU SOOOO MUCH FOR ANY HELP YOU CAN PROVIDE !!! :S

Topic

[dan]

are there any codes stored?

[Craig]

no, the P0300 was the code i was getting at first, then i got it running, brought it to autozone, cleared out the codes, drove it home. The next morning, it through another code .. P1300. However, the night before, I used some engine de-greaser and hosed it out…so i thought that maybe getting something wet caused the P1300.

[dan]

P1300 Is a code for ignition system malfunction, without ignition you have no spark, no spark means no ignition of air fuel mixture, no ignition of air fuel mixture means engine wont run… see if you have spark, if you don’t see why…

http://engine-codes.com/p1300_toyota.html

[dan]

and this out

[Craig]

Thank you for the info on the P1300… I do indeed have spark at the plugs.

Also, I forgot to mention that I had the compression checked, and they were all within 10 psi of the highest (190-180 psi) across all 4 cylinders.

I am starting to think that the IAC valve actuator may be bad… I notice at idle, while driving (coasting), the Tachometer will idle at around 1000 RPM, then dip for just an instant to like 750 RPM, then catch up and go back up to 1000 RPM. I washed the IAC down pretty heavily with Throttle Body cleaner, and worked the valve open and closed with it full of cleaner, so i am pretty sure it is clean… and that seemed to help a little. But if the electronics of it are going out, then i guess that can cause it to still fail. I don’t know how to check to see if that thing is going out however.

I am baffled by the issue. I can drive it around with no problem, then all of a sudden, it will just die while driving (but off the accelerator, like turning into a driveway, etc..). I REALLY need my truck fixed as it is my main mode of transport to and from work.

[Craig]

So, that code P1300 was “Ignition Coil #1” so i changed the ignition coil and guess what, STILL GETTING THE SAME CODE and the truck will not stay running. I re-cleaned the IAC thinking it maybe was still clogged up, it is most certainly clean now.

I am loosing my freaking mind over this thing. I HAVE to get this thing running. And I can not afford to tow it to the dealership or professional. Anyone have any revelations for me?

[Craig]

Well cleared the codes, let it crank up and it ran for a couple minutes before stalling again. Checked the codes and only getting the P0300 Random multiple misfire. My cousin suggested maybe the TPS (Throttle Position Sensor) may be bad… he instructed that I unplug it and see what happens. Low and behold, it stayed running and would not stall out. It does run a little rough and hesitate when accelerating, because that is what that sensor is supposed to help with. BUT not idle stall. So, I’m going to go replace the TPS tomorrow. Wish me luck, after this, it may be a trip to a junk yard to find a EMC.

[Brian]

I think your problem may be rather simple. I have owned, worked on and loved Toyotas for decades.
Your problem sounds like a coil or coils.
How could that be?

A coil is a tight, fine winding of wire embedded in epoxy resin covered by a plastic shell. They tend to crack internally.

You can remove a coil and do resistance tests on it, and it may show that it’s good, but it can still be bad.

When its mounted on the engine, it warms up with the rest of the engine bay, and the heat make the crack expand. When you remove it for testing, it is cooled off and the crack contracts which makes a test look good.

I have a feeling that if you replace the coils with new units your problem will be solved.

Other possible but not as likely culprits.

Bad electrical connections on any or all ends of all the battery cables. Check connections on the battery as well as the starter, alternator and power distribution block aka underhood fuse box. Also the ground for the chassis and to the engine. Lights can still come on, but stall out due to poor or intermittent voltage. Sometimes a bad cell in a battery can cause this too.

Lastly, the egr could have a carbon build up causing it to stall after it gets warm.

Eric has plenty of great vids on all these things.

Coils can be a little expensive, but it is a thing that is common with most of them that I’ve worked on. There are savings for those on the interwebs too.

[EricTheCarGuy]

I don’t think a single cylinder misfire is going to cause the engine to stall. Since you replaced the coil, I think it’s even less likely. Forget about the TPS, same with the EGR. If you don’t have a code for it, then it’s not likely to have anything to do with the problem. I did some research on this and it may be the crank sensor. The crank sensor will be responsible for telling which cylinder may be misfiring to set that code. If it’s faulty, or having an issue, it can cause that code to set as well as cause a stalling problem. Worth looking into anyway.

Keep us posted on what you find.

[Craig]

Tested the Crankshaft Position Sensor with a multimeter, it tested ok… 2200ohm at the sensor, and power the connector from the vehicle.
Tested the Throttle Position Sensor, it had a dead spot at the Idle position, so i went ahead and changed that. The car idles ok till it warms up and has run a bit. Then it dies. I can see when driving, when i let off the accelerator, the RPMs will dip low, then jump back up to running idle speed.

I am still getting a P1300 “Ignition Coil Primary Feedback Circuit” that is now the only code it is giving. I have changed the ignition coil, distributor Cap and Rotor already. The coil goes inside the distributor.

What am I missing here. I really do not want to change anymore parts.

[Craig]

update – OK so no good news yet…
I changed the Throttle Position Sensor and the Crankshaft Position Sensor, and am still having issues. (back in October).
Was STILL dying when I crank it. If I leave the TPS unplugged, i can drive the truck, but with some small issues. Sometimes, it will stall and die when I am driving, it will sometimes, loose acceleration at highway speeds then, if i pump the accelerator, it will catch and get going again. I have even experience where if I try to go over 70 mph, it will do that, but as long as i don’t go over 68-69, it is fine.

So, for the last couple of months, I have been able to get back and forth to work, more or less. Here is the big issue, when it is either very humid out (i live in south Louisiana) or when it has rained… I can barely get down the road without it stalling out and dying. I can get to work (15 miles from home) and then by noon, it cranks and runs fine, I assume that it has dried out.

NOW, as of a couple days ago, I can’t get it out of my drive way. I can crank it up, it will idle ok, but when i give it gas, it stalls and dies.

I got out the manual, and decided to look for a short circuit, so i used my multi-meter, and checked the readings of the IAC, TPS and MAF at both ends (sensor end and at the ECM end). All readings are within tolerances of the manual.

My next steps are to change the IAC, then change the ECM (Computer). Unless someone can give me some other advice.

I am moving to Georgia in a few weeks and REALLY need my poor little truck to work. HELP !!

[Brian]

I feel your problem is solely electrical. I have seen numerous situations where a car runs far worse when its raining or humid and every one it was electrical.
You’ve done a lot already and its all good stuff. Now it’s time to find the bad connections. All ends of all battery cables need to be inspected. Clean the ends if you must. How did the connection on the crank sensor look? If it’s hobbled together that will cause issues. Is the ECU in the engine bay in the elements? If so, disconnect it and look for corrosion in the connections.
I’ve seen your problems also in a car with a starter that was on its way out. The car started fine and the starter made no strange noises, but it was shorted out internally. Getting one of those free charging system checks may help there.
If you have an eprobe you can go thru critical wires looking for internal breakages also. I would trace critical sensor wires like crank, cam, tps and coil connections then to the ECU as well.
I hope you get it fixed man. Also, are you sure your truck was never under water? These issues sound a lot like a flood recovery vehicle as well. Look under the seat and floor mats and even under the dashboard for signs of fine silt like dirt and a musty odor. If that’s the case you may have even more work ahead of you.

[Craig]

[quote=”peshewa” post=155007]Also, are you sure your truck was never under water? These issues sound a lot like a flood recovery vehicle as well. Look under the seat and floor mats and even under the dashboard for signs of fine silt like dirt and a musty odor. If that’s the case you may have even more work ahead of you.[/quote]

It did get driven thru high water once. but it was running the whole time. Water was about up to the floorboards, but did not get inside the cabin.

I have changed the starter actually already, after the problems began from the original post. Thanks for the advise. I am going to do a wire inspection tomorrow. I have a bundle that goes to the distributor, and a few sensors that was under the breather tube, that i removed today. There is a lot of oil all over them, from a leaky valve cover (that is getting fixed in the next couple of days as well). Could be that heat and oil have fouled some wires?

[Brian]

A steady oil leak will definitely degrade over time, wire insulation and connections. Change the leaky oil seal, then clean your engine bay very well. Then take each connector apart and use electrical contact cleaner in each pin hole, make.certain they are dry before reconnecting them.

[Emmanuel]

Did you fix it?

[Author]

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