2.7L will only start if you catch it in gear????

I have a 1998 tacoma 2.7l 5 speed and I have fuel pressure at the rail. New fuel pump and filter. Have spark. New crank position sensor. and it will crank but not fully turn over. sometimes i can get it to turn for a second if i hold my foot on the throttle like an 1/8 of an inch but will not stay running. I have tried holding it to the floor but it wont start that way either. but cannot figure it out. the truck will start and run like a top if i catch it in gear runs perfect.

Any ideas?
Im out of time and money and ideas and need this thing fixed

 

so it fires and runs if you get it rolling and pop the clutch but won't fire off the starter? Maybe the battery and/or the starter is weak and not quite spinning the engine fast enough to get it to fire.

 

Battery is new and fully charged. even tried it with it on the charger

 

starter?

 

starter turns freely and fine like it should

 

but what "could" be happening is the starter kicking in drops the voltage down enough to where the plugs aren't firing correctly.

this could be a starter, starter wire, or bad battery issue so those are the things to look at that fit your issue you describe where is starts as long as nothing is drawing power from the electrical system to do so.

 

somethin along the lines of what keaker said must be happening If it starts and runs fine from popping the clutch but won't fire from the starter. I dunno what else would cause that situation. maybe pull the starter and have it tested just to be safe, should be free at most part houses. Also maybe slap a compression tester on there if haven't already, just to be certain of engine health.

 

but if the battery is 100% and i keep it hooked to a charger while cranking it should have more than enough to fire. Correct?

 

not if the wires are bad or the starter is shorted making it draw more amps then it should, if the starter is drawing all the power there may be none left over to power the computer or fire the coils which is why you cant think your way through this but you must go through the process of elimination bypassing one item at a time until you find the weak link.

my uncle thought he had a bad battery, it would charge and hold a charge just fine but didn't have the power to start his car. it was a shorted starter that would completely drain the battery as soon as it started cranking it just once, he went through 3 batteries before he finally changed the starter because he was trying to use logic to solve the problem rather then try replacing the one part in the system he never changed.

I hate solving problems by parts changing your way through then but when regular logic fails to give you the solution the next step is systematic part replacement which in your case you replaced the battery so now use jumper cables to bypass the wires to the starter and if that doesn't do it then bring your starter in to have it load tested to see if its drawing too much power

 

OK so I checked the starter and tried new wires and jumped it completely and still nothing.

I caught it in gear and let it sit and run for a while. I got a code P0115 which is my coolant temp sensor?

The truck will start with the key if the motor is hot.

Do you think it could just be the faulty coolant temp sensor?

 

If the coolant temp sensor thinks the motor is hot when it's actually cold, the computer might not let enough air in to start the truck. That would be why a little bit of throttle will help it go sometimes.

Maybe try unplugging the air temp sensor that is on your air filter box and starting it with that unplugged. That will put it in "limp home" mode where the computer just gives a standard mix of fuel and air. If it starts, the bad coolant temp sensor is likely your problem. If it doesn't start, then you can continue chasing a potential problem with shorts to the starter or not enough juice to get it to crank.

Bad coolant temp sensors usually give a hot start problem not a cold start one, but anything is possible.

 

Have you checked the main ground between battery and truck? A hot engine is easier to start, turns easier. You might be getting enough juice to bump it but not enough to overcome compression.

You can do a quick check with a jumper cable.

 

It was the coolant temp sensor the whole time. $15 part and about 10 minutes work.

Thanks for all the help

 

this is why engines were so much better when you only had a fuel line and a vacuum line to attach and they didn't have all this computerized crap.

amazing how something so simple and mundane could shut down your engine over stupidity like that