2001 tacoma doesn't start good when hot

I have a 20p1 tacoma TRD with a 3. 4L truck. When I start my truck when it is cold it fires up like it should, but when the truck is up to normal driving temp, and I try starting it, the truck shakes and barely turns over. My mechanic is stumped, he has replaced the following.
Fuel pump
Fuel filter
M.A.S.
Spark plugs, wires and tubes.
He is now installing a new crankshaft position sensor. The problem with the starting issue is that it is not throwing any codes.
If anyone has had a similar problem Please let me know, Thank you.

My tech guy installed the crankshaft position sensor and it starts a little better, but still has the same symptoms, but not as much.

 

Sounds like you might have too much fuel, or not enough fuel. Can your tech guy check the fuel pressure at cold start and then at a hot start???

 

Check compression.

 

Oxygen sensor possibly

 

The MIL does indeed work??

Leaking injectors causing the plugs to get wet. (Jen and Eric`s Saga )

Might be getting enough fuel to cause extra compression making it hard to crank

MAF Crank Sensor O2 sensor will all cause a code to trip

I hope your not paying labor as your mechanic?? guesses his way through your problem

What is next a New ECM ?? maybe a Engine Harness ??

 

Gosh i was totally thinking the very same thing as your last 2 lil paragraphs.

I get its hard to know where to go without a trouble code but with that said vehicle's were diagnosed and fixed without code readers and diagnostic codes for how long?? Older rigs certainly didn't have all these fucking sensors and electronically manipulated doodads to make everything play nicely together though either...idk...

 

Check the ect sensor

 

Just pickin your brain here...
Why do you think that would cause his symptoms?

 

Well i know its not a tacoma but when I had my old subaru my ect sensor was out of wack. Would start run fine til warmed up. Then wouldnt start say going into the store to grab a drink. It would have to sit a bit then would restart. Weird thing which it didnt throw a code. I looked on the tail pipe and had a bunch of black soot told me she was running way rich. I first replaced the bank 1 02 sensor with little improvement. The ect sends info to the computer and if its out of wack can be telling the ecu to dump more fuel in cuz it thinks its cold but its not. Some of these sensor stuff can be tuff to tackle. Best thing id say is hook it up to a "live data" ob2 scanner and see whats going on

 

We all know an engine needs 3 things to start
1. Fuel
2. Spark
3. Compression
Sounds like you have all 3. If you have low compression like if a timing belt broke you would know cuz when it turns over its really fast and sounds like a tonka toy.

 

So how in the heck did you ever come up with the ect as being the problem!? Seems like that could have taken forever to find!

You just start swapping parts that delt with fuel management?

 

Well soon as i found out it was running rich. 2 things off the top of my head was ect and 02 sensor. Gotta be careful some sensors its better to go oem. My old vw i had after the service, the alternator went out. Replaced twice with duralast alternators. Went oem on the 3rd time no problems after that. You outta check out gettin a scanner save you money in the long run. They will show you fuel pressure, intake temp, coolant temp. Bunch of cool stuff they tell ya

 

My suggesstion is to check out the ignitor. Typical failure mode for ignition related electronics is no start when hot. Next time it won't start check it for spark with an inline ignition tester at one of the spark plugs.

 

I don't think he meant ECT. IAC sensor?

But yeah, Jen and Erics saga lived on.
They found the issue by using a bore scope to visually see the injectors leaking down.

I gotta get one of these. $70 at HF!

 

Good info. Thanks!

 

...Seriously though did you have to pay to have all those parts replaced and it fix nothing? Honest question, I've never brought a vehicle to a mechanic unless its for an alignment transmission issues.

 

AIT. This helps me. I was thinking how can the Electronic Control Transmission button be involved with this issue?

I think I was a victim of auto correct.

 

I was just sharing an expierience I had similar to his thought I could help