A different starting problem with the 3.0 V6
 

I am having a starting problem with my 95 3.0 V6 Auto.
If I hit it just right with the correct amount of gas it will start and run after sitting a completley cooling (usually over night). If I miss it though I have to unplug the fuel pump because anymore cranking will only flood it. I unplug the Air meter (it kills the fuel pump) and crank crank crank and crank some more until it fires and with me giving it gas will stay tunning long enough to plug the air meter back up. After this it will run fine, but doesn't seem to idle up. Its kinda like starting a carb engine with no choke.
Once it is warmed up a bit it will start just fine.
Things I have changed,
Cold start injector (its unplugged now it just floods the motor)
Timing belt
ECU
Fuel pump
Air meter
Fuel Pressure regulator

I have already toasted one starter cranking so much please someone help me on this one.

come on, someone knows. please help me out. toss ideas out anything

have you check for codes? is your check engine light?

no cel, no codes. checked multiple times.

You say the cold start injector is flooding the engine. That would mean the cold start timing switch is also working. IOW, it operates the cold start injector until the motor has warmed up to a certain degree. Once it is warm to that degree, it should no longer energize the cold start injector. The timing switch is on the back of the motor between the manifold and firewall.....first or second switch on the left. It's the big one.

Anyway,you may be having a problem with the idle air control valve located on the bottom side of the throttle body. It's suppose to be open while the motor/coolant is below operating temp. When the motor's cold, the ECU is open loop mode and injector more fuel/a richer mix. But, you have to have enough air to properly fire that much fuel at start up and cold idle. The idle air control valve is the way this is accomplished. If it's stuck shut while cold, you won't get enough air. So, hard to start and floods out until the motor warms up enough for the ECU to lean out injector duration/amount of fuel needed.

I guess I'd start there. Otherwise, it could be the coolant temp sensor.

Ok...but if one of those sensor are out...it would show a code and the cel will be on..right?..

Matthew, Is the Air Valve the same thing as the idle air control valve? Thats what it called in my manual.
Anyway it makes since to me and I will check it as soon as I get a chance. Is their any way to clean it or will I need to replace it if found bad?
The cold start injector can be plugged up and the motor will start and run fine as long as its already warm. I am thinking the timing switch is ok. I think it is just doing its job and I am trying to stop all the fuel I can, so the air valve makes good since.
The tempature guage works so I am guessing its not the coolant sensor.
But please steer me in the correct direction if I am not correct in my thinking.

Norcal, good question so it leads me to belive the sensors are good.

I'll let you all know what I find with the idle air control valve (Air valve)....

Thanks

OK someone please point me to the cleaning the idle air control valve in the FSM on this website.. I can even find the FSM...LOL

the front screw on the throttle body is the idle air control screw. you can underwind it all the way out and clean it. spray some carb cleaner or throttle body cleaner in it and blow it out. then open throttle blades and clean that area out and the port for the idle air. its easy.its the one in the center directly to the left of wear the hose goes on. its a flat head. cant miss it. but id recomend marking it, then turning it in all the way, counting the turns. that way whenyou put it back in you can get roughly the same spot. also take a note at your rpm before and after as half a turn will change engine rpm slightly.


the cold start injector swith is a problem in these. stays on longer than it should and floods them. seen it happen a few times. try it. its at the back behind intake beside coolant temp sensor. i think its the one on the right. theres 2 and they look the same. hope this helps.

OK cleaned the idle air control valve and still no better.
If I have the cold strt injector unplugged would the cold start timing switch still matter?

Anyone have anything?

Not necessarily. If the coolant temp sensor circuit is disconnected, IOW, not sending any signal at all, it will throw a code for that. But, if it's just sending incorrect voltage it will not. Atleast, not for the coolant sensor. You may get an O2 sensor signal, though, because the engine may be running too rich. It's kind of a primitive diagnostic system that way.

The idle bypass screw is not the same thing as the idle air control valve. The idle bypass is what you adjust to regulate idle speed, but the idle air control valve is under the throttle body. Here's a link.....

Read it....
http://www.autoshop101.com/forms/h21.pdf

The coolant temp sensor is not the same as the coolant temp sending unit. The sending unit is for the guage, but the sensor is for the ECU for EFI control. Much different.

If you have the cold start injector unplugged, the timing switch won't matter. The part that it's suppose to help operate (cold start injector) is unplugged and the switch is not affecting anything else. Theoretically, if the injector leaks, it can create a situation such as yours. Or, if the timing switch is continually grounding thereby continually activating the injector....same thing. But, if you unplugged the electrical connection at the injector when the engine has reached operating temp and the engine still stalls, then the injector is leaking or it's something else......like the idle air control valve (IAV).

So, now that you know the differences between parts, hopefully you can troubleshoot a bit better. And, now that you have two threads going on the same issue ????? you should get plenty of input. :wrench:

i would also check your throttle position sensor. that controls the idle as well. if it isnt working properly or isnt adjusted properly, the engine will not want to start very well, and will not idle very smooth

OK, I'll change the coolant temp sensor because I have one of those already.
I think maybe we are getting off the actual problem a bit. Just a refresher.
It wont start anymore at all. It just cranks. Doesn't hit at all doesn't even try to start.
It has fire and it has fuel. I sprayed starting fluid directly into a plug hole, installed the plug and cranked it with no results at all.. Shouldn't I have gotten a sputter or something?
That is why I am leaning toward fire and not so much as fuel.
I also took put heat on the air idle control valve and got it to close. Then when it cooled ot opened up again. it's not open much but it is open when cool.

Coolant temp sensor installed no change.

Well, that's just the nature of EFI troubleshooting. It could be one of a few things causing very similar problems. So, you just have to track it down.

I recall someone mentioning you may be having an ignition system issue. Team420, I believe it was. Might test your coil next. Sounds like your cold idle air valve is working, and I'd think, yes, you should've atleast gotten a sputter if you were getting adequate spark.

Hey there, I'm new here, just found the site and registered today. I am having the same problem you have described. I am able to tow it and it will start and after running a few minutes will start right up and run fine. After sitting several hours, back to the same problem. Have checked out pretty much all the same components that you have. If you found a resolve to your problem could you please let me know.

Yeah I solved the problem, I bought a Dodge....
Really the truck is still sitting out there waiting for me to regain intrest. I think my problem is in the injectors. I have thought about taking them out and testing them one at a time but the new Dodge Truck with ice cold air and me having little to no time to work on it has kept it sitting alone under the back deck.
If you figure it out give me a shout on here. I'll do the same for you....



Also coil is good, spark is strong.:fire2:

Thanks for the reply! Found a new problem today though, it has a blown head gasket and is getting antifreeze in the oil. Just started that yesterday. If you know any sights to buy a good used engine cheaper than rebuilding this one I'm searching. Thought about replacing the head gasket, but this engine has 246,000 on it, so if I was gonna get that far into it, I should probably go ahead and rebuild or replace it.
Thanks! FRUSTRATED