williamb82

When the car has sat overnight, and I try to start it in the morning when it is fairly cool, it will not start. it just spins over. If I unplug the MAF and try to start it, it tries to fire then stops. Then I plug it back in it fires right up just fine and as long as I let the car warm up a bit before driving, it is fine. I have also found if I unplug the TPS, it fires right up, and I can plug the TPS back in and it stays running just fine, again, I must let it warm up a little bit before driving or it will stall.

The IACV has been replaced with a known good one and cleaned. The Engine coolant temp sensor is brand new. The MAF has been replaced with a known good one as well. At that point I figured must be the ecu, so it has been replaced also, same issue. TPS has been adjusted and is in good working order. I have tested it. No dead spots etc...

I have done some research and people claim it is a bad FPR, or fuel pump etc... I know this is not the case. The fuel pump is less than a year old, and the FPR was swapped with a known good one awhile ago. Also, I wired a push button from +B to FP so that while the key is in the "on" position, I can push it to make the pump run, and it does as I can hear it, but priming the pump does not make a change. I do not believe it to be a clogged fuel filter either as it runs and drives fine, and when the TPS is unplugged it fires immediately. This is also why I do not believe it to be spark related. The plugs, wires, cap and rotor are less than 2 years old.

Has anyone encountered this issue before, and where you able to solve it? If it is warm outside, the car fires right up by barely bumping the key over.

Im at a loss at this point and have no idea what else it could be. If it was firing then dieing, id say maybe the EGR valve was stuck open, but it doesn't even attempt to fire, just spins. There are no vacuum leaks I am aware of, and the hz for the MAF is in the normal range while cranking cold as it is when hot. Checked this with my SAFC 2 that is connected. Also checked the TPS voltage while cold and warm, and they are also the same. I have no idea what it could be. I am tempted to swap a spare set of injectors in and block the EGR off just for the hell of it to see if it makes a difference, though it should not, so I would rather not go through the hassle if I don't have too.

skytechja

sound like you pretty much ran through every single thing...

did you also check your plugs and plug wires (if its the non-vvti)

kene

iTrader: (2)

Are there any codes at the when it starts and dies.
And if not have you tried 3 or 4 times of "starting and dying" back-to-back so that a code can 100% register in the ECU? (non-intermittent error)

skytechja

i didnt read the lil exert from the original......

if you unplug the tps and it fires immediately.... please try and properly replace the tps ........... or it will most likely be your tps circuitry ....


break out that multimeter and wiring diagram and test for continuity from all of em wires and reckeck grounding wires n all of that...


if ur tps is connected and your getting em bad startt n its dieing,, it means whatever signal the ecu is getting is wrong

williamb82

Well, the thing is it will also start by unplugging the MAF. I do plan to swap another TPS on it, just have not had the chance. I will probably do that in the morning. As for the plugs, they are recent, as are the wires. The wiring from the ecu to the tps is fine, otherwise I would not have the proper readings at the SAFC2, which I connected at the ecu. it has been connected for nearly 2 years. The voltage at idle is fine on the tps, as is the percentage etc...

If I check engine codes after the start/die thing, it is for the maf and air temp sensor, which is correct since I unplugged the MAF for that to happen. If I unplug the tps instead to start it, I get a tps error code, because the tps was unplugged. Never all 3 in any scenario. It is a very strange issue. If I wait till like 8-9am in the morning, itll start with no issue, and no engine codes.

skytechja

ohhhhhh ok

@ 8-9am the time is a bit warmer......

so once the engne itself is really cold it wont start without u disconnecting either tps or maf....

interesting.... sounds like a lil kid who doesnt wanna get up early ... lol

williamb82

Pretty much. I had the issue after fishing one night. Went to leave at like 1am, car had been off since like 6:30pm. However if I drive it to work, when I leave at 5pm, it starts right up just fine even though it has been off since like 7:30am. The time it sits is not the cause, it is solely the temp as far as i am concerned, however the air temp sensor, and engine coolant temp sensor both check out to the proper ohms at the ecu connectors. i checked this weeks ago and compared the resistance values with the chart in the tsrm based on the current temp when I took the readings. Engine had been off all day so was at ambient temp.

By the way, in the morning, if I let it warm up a few min before turning it off after having the issue, it starts right back up no prob. so a slight change in temp in the engine resolves the issue. But its about to start getting cold out and I do not want to have to start disconnecting the stupid tps every time I need to start the car.

skytechja

yes... i totally understand what ur dilema is right now.....

wow....

its all about the temp of the engine ..... in the day time its warmer so no issues... its just from the cold temp that it gives that issue...

computer doesnt throw any codes at all either......

im gonna consult my mech n hear what he n his friends have to say about this one

williamb82

I posted in hopes someone has had this issue before, and had some oddball thing they finally did that ended up fixing it. Using logic, it just isn't going away. It did start this morning, though it was a hard start. Didn't change anything last night for it to do so.

skytechja

ohhh ok...

question though... the spark plugs that are being used.. are they factory spec ?

williamb82

I run coppers. Least resistance of any plug you can run. I dont run them as long as you would platniums though. The plugs are not the issue. Car isnt boosted. I run coppers in my 7mgte as well, but change them ~10k miles as they burn up faster than platnium or iridium.

I changed the TPS this morning. The part number on the TPS installed is not the same as the 2 possibilities I found online, which is weird. I never changed the TPS myself, so I guess someone did it for the previous owner. weird. Anyway, I had 1 in the proper part number and put it on and adjusted it. Car fired up fine, but it was also about 9am. Real test probably wont be until Monday morning when i leave for work. Fingers crossed.

skytechja

wow....

well im anticipating good results and the answer to your problems.....

i had already rellaced both tps on my car.....
when i used to start it wud start n run like **** for few seconds n then shut off... u would have to gass it for about 5 min for the engine to really warm up to run properly....

but he prob was a dead tps n damaged distributor brush...



well i hope all is well on monday !!!!!!

williamb82

Well, ran fine till I filled up with gas, then after leaving the gas station the engine light came on. Car still ran fine. Checked it when I got home, code 71, egr. It is a federal ECU, so no EGR temp sensor, so im guessing the resistor inside the ecu for this circuit has gone out of spec. Gonna be fun trying to find it to replace since you cant get a schematic for the ecu.

skytechja

ohh snap.... sorry to hear...

yes its gonna be hard to get that schematic still...

u tried resetting ecu and see if it will still throw that code ?

williamb82

This was after resetting the ecu. The code has no effect at all on the way the engine runs, just an annoyance.