My car won't start when hot. Not the battery,not the starter. It tries to crank and almost sounds like a car with the timing to high. It cranks fine cold and runs smooth and strong.

 

It may be a case of the Engine Coolant Temp Sensor (ECTS) sending the wrong (e.g. always cold) temperature reading to the ECU. If the ECU thinks the engine is cold, the fuel mixture may be too rich for a warm engine -- thus resulting in a hard to start condition.

Here's a video on how to test the ECTS below to rule out that possibility.

http://www.boredmder.com/FSMs/Nissan/Maxima/1995/EC.pdf (Page 108)


And this video.

 

I don't think that was it. I tested it cold at 2 ohms,when heated ohms dropped. I cooled it way back of and put it in the car started. I wonder if it is really bad. It acted funny all winter. The warmer it gets the worse it gets. I'm gonna get a new one anyway

 

Have you checked the spark plugs for any blackened or wet (fuel smelling) plugs as soon as you can after shutting off the engine? Do you smell fuel in the exhaust once the car starts when warm? I had a hard to start issue that was caused by flooding from two failing injector o-rings.

 

If it's not the ECTS (my first suggestion), then I'd replace the FPR. This happened to me, a hot max and it shut off while driving. Wouldn't restart until the next day. Replaced FPR, and no more issues.

 

I think the FPR is a maintenance item after 15 to 20 years.

If you do replace the FPR, you might want to replace the brass factory screws with stainless socket head cap screws (4th gens) use the following screw sizes. I pick up Hillman Stainless Fasteners from hardware stores like Lowe's or Ace Hardware.

Injector Caps and the Fuel Pressure Regulator use M5 (size) 0.8 (pitch) x 16mm (length) with M5 lock washers.

You'll see the reason for the screw change once you get into replacement.

 

I think it started back before christmas, its just been so cold it never has not started till it got warm outside here. There have been a few times on cold mornings i could smell raw fuel thru the vents and outside some. When its starts in the morning and the car is cold it has a bit of a surge to it till it gets warm. I am going to pick up a Temp sensor anyway. FPR= Fuel pressure regulator?

 

FPR= Fuel pressure regulator? Correct.

Also, to help clear a flooding condition when the engine is hot, you can hold the accelerator open. When mine started the flooding problem, I had to hold the accelerator all the way open to get it to start period.

As for ECTS and FPR, I've been using the BWD/SMP Intermotor brand without issue. Rockauto usually has the best price. But when I'm in a hurry for parts on weekends, I buy from Advance Auto online (specify in store pickup) and use coupon codes TRT30 or TRT41 (depending on total purchase amount) for 30% to 40% off.

 

I tried holding it to the floor, it didnt help clear it up. I recently tested all the crank sensors and cam sensor. I havent replaced the fuel filter on this car since i got it either. Not sure when its ever been done.

 

That's one of those maintenance item that is often neglected.

 

Yes it is and i keep forgetting about it. ill start with the temp sensor this evening. I work 12 hour days so its late when i get home. Ill check the FPR and change the fuel filter this weekend. Maybe change the FPR. I also thought maybe an injector leaking fuel after i shut it off. Its def heat related tho i think

 

I'm betting you will find the issue.

 

ok. just converted my ohm reading of 2.0 ohms to Kilo Ohms. i had 2 Ohms which is .002 ohms. My sensor should be bad. 2 Kilo Ohms is 2000 ohms.

 

Oh well,not the temp sensor.. Guess I'll start throwing parts at it. Im going to pick up a FPR on the way home and change it tomorrow. It seems like it is flooding when it is hot and you restart it or try. It couldnt of messed up when i was off 12 days in a row.

 

mine ( 99) did this last summer, quit when it got cooler. don't know if it will come back this summer.
when its summer, flooring the accel pedal will start it or,
crank for 2 seconds, turn switch off and immediately start again, it always starts this way. what does the off on with the key do to start it?

 

Its not the FPR either. Oh well. I guess I'll sell it. I sold a dependable car and got this and haven't put the tools down yet

 

Seems it was the damn starter. I put one on it last year. It actually quit today and I got another one under warranty. It even cranks different cold and hot. I would of never guessed it by the symptoms. Never had that issue before, but I guess that starter was actually bad the whole time.

 

Congratulations! That's definitely an edge case if I've ever seen one. Good to see it worked out.