ScottyC

iTrader: (1)

Well, all was well on the new 4runner for over a week. Drove great, runs great, but today after driving it to work, then back into town to run some errands, it wouldn't start. Went back this afternoon, and sure enough, fired right up.

When I bought it, I was told that it used to have a hot starting problem, but the guy replaced the fuel pump, regulator, and filter and it never did it again.

Here is what I can confim.

1. There is fuel at the rail.
2. I am getting spark at the coil when cranking to start
3. It has an aftermarket Clifford alarm with keyless entry. I have no idea if it has a kill switch or not. Based on the fact that it fired right up later after the motor cooled, I would lean against this being the issue.

I am clueless on the 3.0 motors. I am getting a 25 & 26 code on the CEL, but that has been there since I bought it and it ran fine prior to this issue. It does have a brand new O2 Sensor as well. And, yes, I have reset codes a couple times and it still throws the 25 & 26 after a day or so.

What sensors would lead to not allowing it to start when warm? Any other things to check just in case? I hate not being able to trust a rig.

I have an extra coil, and plan to swap out the old one to see, but based on the fact that I have spark through the coil when cranking, I doubt that is the issue.

EGR maybe?

keithdphan

cold start injector is leaky.

ScottyC

iTrader: (1)

I'm not smelling any gas in the engine compartment at all. I am leaning towards that though. Would a bad Engine Coolant Temp Sensor Circuit do this?

keithdphan

unplug the electrical trigger on the injector and the next morn try to start it. if it it struggles to start then its the temp sensor, but if it starts like a champ then the injector is faulty.

ScottyC

iTrader: (1)

I am about ready to just drive this damn thing off a cliff. :mad3:


Today I swapped the distributor cap and rotor. Then I decided to run some checks on the rest of the sensors. Everything seems okay from what I can tell.

Still, even after its warm it will not start. But, I can get it to start by simply unplugging the Engine Coolant Temp sensor on the motor itself and plug in a room temp one. However, it still runs like dog-ass once its warmed up with a fairly quick fluctuating idle.

I bought a compression tester with the metric fittings today, but don't have time to do it until tomorrow. I figured I would install some new NGK plugs at the same time.

Has anyone had a similar issue to this? WTF was it?

So far, I have swapped out:
1. Dist cap and rotor
2. Engine Coolant Temp Sensor
3. Cold Start Injector
4. AFM and tubing
5. Cold Start Time Sensor
6. Cleaned the throttle body

The fuel pump, regulator, and filter are new. I have verified that it cannot be them by bypassing them switch so it runs constantly and it still won't start when warm.

89yoter

Sorry I cant be of any help but I am having the exact same problem with my
3.slow cant figure it out for the life of me. I switched the temp sensor and such out and now I cant even get it to turn over I give up for the night. I changed the cold start injector a few days ago didnt make a difference.

ScottyC

iTrader: (1)

Try the Cold start time switch. Mine cleared up again, so I cannot confirm if I fixed it or if its just being moody.

tc

I had "vapor lock" type symptoms. Replaced the coil/ignitor and all better.

They are kinda known to have a heat-soak problem apparently.

89yoter

I plugged in sensors out of a parts runner I have. When the cold start timer is plugged in it wont even turn over I unplug it and it turns over. So I put the original snesor back in and it turns over just fine and starts up when its cold. The sensors have the same part number. Im assuming that the sensor out of the runner is no good and causes a short that wont let the motor crank over. However when I Ohm the sensors according to my shistey haynes manual they are still good. Toyota wants 230$ for the cold start timer and 150$ for each of the other sensors in that coolant bypass block. I dont really want to throw away 500$ and not solve the problem I was wondering if anybody can help me. Yes I know I need to get a FSM but I dont have one right now. I am unsure of the other 2 sensors and how to OHM test them or if they are even related to the starting sequence. Sorry for the long winded useless post.

tc

FSM for a '93, yours should be pretty similar:
http://personal.utulsa.edu/~nathan-buchanan/93fsm/