I have been having intermittent crank and no start problems with my 2010 Toyota 4Runner. The car has around 186k miles on it. It goes into crank and no start cycle after driving around for a while and then stopping.

Before I was using jump starter pack, which was helping every time, but now it doesn't. Not sure why extra boost would solve the problem. The last several days I had to be towed twice to my house.

When the car was still in crank and no start cycle I started to do the diagnosis. After eliminating NO Spark issue, I moved to NO Fuel issue. I started by spraying starter fluid into intake manifold to bypass fuel pump completely. After several cranking attempts it finally started. The engine hesitated a little bit, burning starting fluid, and then it started to run normally. The car would fire up right away, like there was never an issue.

I started to test the fuel system even further. Power circuit to the fuel pump and fuel pressure were checked, and everything was up to specs shown in the repair manual. Today I replaced fuel pump, hoping that this would solve the problem. The car starts up and runs fine, but I am having intermittent crank and no start issues.

Here is the video of the problem I am describing.

Intermittent starting - fuel pump just replaced - YouTube

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This is everything that has been done and tested on the vehicle.

BATTERY

The battery is AGM battery that is fully charged. I have a battery tester that checks every single thing.

- CCA are at 710A
- 12.5V charge
- Alternator charging AGM battery at 14.5V

...

FUEL

Fuel Pump (just replaced with BOSCH fuel pump)
- Fuse is fine.
- EFI relay is fine.
- C/OPN relay is fine.
- FP is receiving positive input with key in the ON position, but no negative input. With key in START position the pump is receiving both negative and positive inputs.
- Fuel pressure is 50 psi with key in the START position.
- Fuel pressure is 36 psi with engine not running. The pressure don't drop.

Fuel Injectors
- Did a listening test on 5 (couldn't reach the other one). Every one of them clicks. No misfire codes.

...

SPARK
- Did spark test one of the the cylinders. > 1 inch spark.
- No codes for camshaft or crankshaft position sensors.

I had a similar problem with my Jeep Wrangler years ago. Wouldn't start when it got hot. Turned out to be an intermittent crank shaft position sensor.
Even though yours was OK when you tested it, it may be intermittent under the right conditions.

Does it start if you keep cranking it? Any signs of chewed wiring or mouse nests?

Do you have access to Techstream or a good scan tool? There will be a P1604 code stored (no MIL or anything a low end scan tool can see) along with freeze frame data from the event, which has info like rpms from the crank sensor, immobilizer status, fuel pump activation, etc.

I wish I saw this reply a little earlier.

P1604 code was indeed stored. I didn't know about the freeze frame data from the event. If I only knew about this I could have narrowed down the problem to what it really was.

I don't have a scan tool, but I use OBD android apps for diagnostic purposes. The 3 that I use are Car Scanner, Torque Pro, and OBD Fusion. These were enough to do diagnostics for Engine Coolant Temperature Sensor, Crankshaft Position Sensor, MAF Sensor. For fuel pump I used DIY fuel pressure gauge.

Is it possible to read freeze frame data from the event on OBD android apps, or I need an actual scan tool for this?

At this point, I really want to invest in a good diagnostic tool that will prevent this sort of headache in the future.


Making long story short, I found what the problem was. It was the immobilizer chip in the key. If I had freeze frame data from the event with immobilizer status, I would have narrowed down the problem in a few minutes!

I found out about it in a very dramatic way when I was on the edge of mental breakdown trying to start the car that again would not start. I forcefully turned the key in the ignition and the plastic part broke off from the metal key. When I got another key and inserted it into the ignition switch it worked fine.

I returned home and removed and glued the key back in place. The car would not start with the old key, producing the same symptoms as before. It would start with a new key without problems though. I went ahead and cut out RFID chip from the old key and taped it to next to the ignition switch. With it in place I tried to start the car with the old key, and it worked fine. With RFID chip in the casing, the key would not work. Interesting...

I spent two weeks trying to diagnose the cause of intermittent crank and no start issue, looked at every system in the car, changed a bunch of parts, and never even considered that the problem could be as simple as this.

The funny thing is that if I didn't get mad and broke the casing off of the key, I would have never figured out what the problem was.

Glad you found the problem. That is a new one on me. I have never heard of the chip going bad. They are usually bullet proof -- the key fob battery, yes, but the chip? I'll have to try and remember that one.

Thanks for letting us know what the problem was.

If I have exact time of the event, can I pull what was happening from the Vehicle Control History in Techstream?

I installed Techstream along with drivers for several cords I ordered. Still waiting for the cords to arrive.

If this information is still in the memory, what are the steps to pull it up?

I've also had an episode where an aftermarket key properly added to the system, just randomly stopped working sometimes. Crank no fire situation as well.

How did you find out about it? I hope you didn't take the approach that I took - tracking the problem by the process of elimination.

1) Knowledge that unauthorized chipped transponder keys prevent fuel delivery is a common security feature
2) A healthy suspicion of the quality and reliability of a back alley aftermarket locksmith key
3) Simple experimentation with multiple keys