96 2.7 Hot Start Issue HELP

I need help big time, my truck starts fine in the morning when its it's cold, but if I drive it around go in a store and try to crank it again when hot, it either has a really hard time or won't start at all.

I have tried EVERYTHING I can think of.
Fuel Pump, Fuel Filter, Fuel Injectors, Fuel Pressure Regulator, Spark Plugs, Wires, Distributor Cap, EGR Valve, IAC, Coolant Temp Sensor, probably something else. I just cant figure it out at all. Its stressing me out. I haven't put a whole new distributor but it's getting good spark so I dont think it's that.

I've heard maybe camshaft/crankshaft position sensor, but I dont know it seems like it just doesnt get fuel when it's hot. Anyone have ANY idea what's up?

 

In this whole ordeal what codes have you pulled?? This will point us in a direction critical!!!

You have a crank but will not start?? Does not crank ??

These are all new parts tested before installing?

Now you have introduced new variables to the equation .

When it does not start what do the plugs look like??

No fuel or to much fuel ??

What is the charging system doing ??

Possible the EFI or Circuit opening Relay coil gets hot and opens.

 

It hasnt thrown any codes at all. It cranks and cranks but does not start. All new parts work like the should. The plugs look okay a little white but nothing too bad. As far as the fuel I haven't been able to test the fuel pressure because when it happens I'm not near a mechanic and it need a special pressure guage as it has no valve for one.

 

It may seem like not getting fuel because it's true, it's not getting fuel. Not due to faulty fuel system component but due to the ECM intentionally NOT energizing the fuel pump, injectors, etc. One of these conditions that can cause this and thus 'no start, but crank fine' is in fact the cam position sensor and the crank position sensor. The ECM has to receive the signal at a certain time to know the timing chain/ignition system is in time. I'm not sure if a code is usually thrown when this happens or not.
Something to check anyway

 

Next time before a hot start R&R the gas cap. If it starts normally after, it's the EVAP flooding the engine.

 

Great suggestion dude

 

I tried that as well. No luck.

 

I see what you're saying. Someone else had told me that but I also read somewhere since I posted that distributor vehicles may not have cam/crank sensors.

 

A faulty Purge Selnoid will vent gas vapor into intake flooding the engine.
Try flooring it on hot starts?

 

Flooring it does not help either. And if it happens to catch but is really weak and I press the pedal it will die.

 

And igniter can definitely cause the symptoms you're describing as well. Pretty sure your igniter is in the distributor. There is a way to test it, it's in the FSM. My FSM is the coil pack one, year 2000 or I'd look it up
And I'm not sure the earlier first gens, ones with distributors, lacked those sensors.
I'll try and search a diagram for the distributor ignition 3RZ 2.7

 

That rules out tank pressure sensor and purge Selnoid. Cruiserguy may be onto something with Cam and crank sensors. IDK about Carburated with or without sensors.

 

It’d be nice to try another ecm

 

They have cam and Crank sensors and will trip a code .

They will also trip a code of the ECM does not see the signal from the igniter

All 3 will shut off fuel.They are one trip codes and will trip on cranking

OP your Check Engine light does turn on with the ignition switch in run engine not running ??

 

Try a used Denso distributor. On the 1996 4-cylinders the cam position sensor is built into the distributor, so it could be that or the coil, so that's why I say to replace the whole thing. And aftermarket distributors can cause problems for some reason, the coil and such are just not as high a quality as Denso. You can inspect and test the coil specs (primary/secondary resistance), but sometimes the problems don't show up during that static test. Check for cracks or burns on the coil.

On the 1996 the igniter may be mounted on the passenger side above the wheel well, but that should throw a code if there is a problem.

You can also read the live data before you crank the engine and check that all the sensor values seem reasonable, like coolant temp and air temp.

 

I have a 1996 Toyota tacoma 2.7 4x4 with the same issue. Winter time it runs great. Summer time when it's hot outside it start great the first start up but once driving around in the hot weather if you shut it off. It doesn't want to start. It will crank over. Like YamahaKid says above it just keeps cranking over like it's not getting fuel . But if you open the hood for about 15-30 minutes. It will start back up. I have read on other forums it could be the mass air sensor getting hot. So I bought a k&m cold air intake which relocates the mass sensor forward not so much over the header like the stock air filter system, but that didn't help. But it has something to do with it being hot outside. I just can't figure it out either.

 

I dealt with that exact problem for years with my '96. It always started eventually so I didn't spend a lot of time diagnosing. One day as I was leaving the house the truck was very sluggish so I backed down the driveway and parked. No CEL but I had a code pointing to the MAF. Replaced the MAF and the hot starting issue disappeared completely.

 

Was it a aftermarket MAF or OEM? Just curious, my '95 has the same hot start issue, but it'll start, most of the time, with the pedal to the floor, standing on your head,,,, sometimes.
Mine has been like this for years, I just put up with it. Usually it'll start up after 15 to 20 minutes.

 

The faulty one was original to the truck. I replaced with a Hitachi MAF0053, reportedly built to OEM specs. 4 years later still working great with no hot starting issues.

 

, Thanks bud