Home Forums Gear Hunting Trucks and Four-Wheel Drives 2002 Tacoma hard to start

I have 6 cyl Tacoma 4 door and it is having a hard
time starting, sometimes it fires up after a few cranks
other times it might crank for ten seconds. Replaced
the camshaft and crankshaft sensors after pulling the
codes but didn't help. Anyone know the real fix?

Thanks in advance
Chris

Did a dealer do the diagnostics on it?

When is the last time you replaced the fuel filter?

Chris, more details may help. Is it only when cold - when hot.. Does it start better if you feather the gas pedal.. Does it run fine when it first starts up.. Fuel filter would be an easy start but could me something else. How many miles does it have.. It sounds like it had CEL codes before you changed the sensors, have they stayed clear since..

Did you do a compression check? How many miles on it? When was the last time the sparkplugs were changed?

without more info here's my guess

it's fuel oriented, pump going bad or more likely the fuel filter

I have changed the filter, it has 99,268 miles on it
the check engine light did come on for the sensors when
I changed them. Then it came on again once after and it was the
camshaft sensor again, reset and hasn't came back on for a
month now. Next step is plugs. It used to start fine cold and
hard once warmed up, but now it's all the time. Just cranks
too long.

Chris

O2 sensor is normally the first to go

The 02 Sensor should trip the CEL. Still not enough specific info to diagnose. If the plugs haven't been changed they are due anyhow. Then I would try cleaning the Idle Air Control (IAC) and the Throttle body. Are you running a stock air filter?

Would the O2 sensor pull a code? I'm planning on changing the plugs and doing the 100,000 tune up, and it has the K&N filter and air induction on it. I have read about others on the net doing the same thing, but no one has a fix. I went to start it this morning and it cranked for 5 to 10 seconds before it fired, got to work and shut it off, tried to start it again and the same thing, 5 to 10 seconds and then it fired. The timing belt is in good condition, checked when the sensors were changed. The net says that it might be the cold start sensor, but I can't find where its at.

Chris

CT, I bet the problem started after you put the K&N Filter on it. While they are good filters, the oil off of them coats the wire on the IAC (I believe IAC, they are MAS on the 4cyl) and the computer don't get a good reading. Get you some Mass Air Sensor cleaner and spray it off, making sure not to touch or drop the sensor. Replace it and put in a factory filter and I bet your good to go. Yes, go ahead and change the plugs as they are due. Let us know.

I think you have to achieve a certain fuel pressure before the computer will turn on the ignition right?

My '97 Z71 didn't start right away unless I turned the key on and waited for the fuel pump to quit runnning. Then it would light instantly.

If that's the case, maybe it is your fuel filter or something else preventing pressure buildup.

Also, while I can't say for certain on the V6, the I4 has the ambient temperature senor in the air box. This too can get coated from the oil of a K&N Filter. When these sensors get coated they give false readings to the computer and it sets the air/fuel mix wrong and will cause hard starting. It could be a combination of several things, but as a general rule, the K&N is prone to causing problems on the Tacos.

Thanks I'll try this and see what happens. The k&n was in it when
I bought it so I'll try to find a regular filter and housing for it. I'll let you
know.

ECU.

Tunacan,

what is ECU?

My bad not the ECU. Try cleaning the MAF ( mass air flow sensor)

Look at this link

http://www.yotatech.com/f2/maf-cleaning-165411/

http://www.4x4wire.com/toyota/4Runner/tech/OBDII_ECU/

My truck was doing the same thing as yours and this helped. I seafomed it while I was at it.

Google seafoam and youll get some good reading.

Also make a post on yotatech.com

That site gets so much traffic and its crazy the things these people know about tacomas.

You might also want to do a search on there before asking questions.

Tons of good info

Check the vacuum line on the fuel pressure regulator for gasoline. If it is leaking fuel into the manifold the engine will be slightly flooded and start hard. Especially when warm.

Jerry

Did the maf, didn't work. The vacuum line didn't have any fuel in it. Still at a loss with this.

I had a brand new 1996 Toyota Tacoma V6 extended cab. That thing was hard to start from day 1. Once, when it was only a month or two old, it took so long to start I almost killed the battery. Traded it in after one year with 7,000 miles on it. Took a bath (of course); never bought another Toyota car or truck.