I have a 97 SE that has had a warm start problem since I've had the car and have never been able to diagnose the problem. The car starts perfectly fine in the mornings. The problem occurs when I get the car up to normal temp. and let it sit for 45min. to 2 hours or so. It has plenty of cranking power, it just takes a little longer(6 sec. or so) to finally turn over. It almost acts like it is choking itself out. If I get gas or run in and out of a store real quick....no problems. I only have an extended start when the car has sat for a period of time. I have heard that the coolant temp. sensor can cause this. I changed the sensor and still same problem. Could I possibly have a problem with the coolant temp. sensor harness? This is really annoying and if someone has had this problem, your input would greatly be appreciated. All other suggestions would also be appreciated. Thanks in advance

 

Am I the only one with this weird warm start problem?

 

I have this exact problem, but unfortunately I can't give any insight as to what it is since it is still plaguing me. I'm simply subscribing to this thread to hopefully get an answer to this problem. If someone comes up with an idea on how to fix it, we now have at least two cars to try it on.

 

I have this problem as well...very annoying. Very strong cold starts, and then when the car sits for an hour or two, after being driven to operating temp on the previous trip, it seems to stumble to life...very weird, very occasional, but very annoying. I cannot off insight as well...hopefully someone knows a fix. But if you replaced the sensor, and there isn't any other causes, then you're right, the next plan of attack should be the harness.

 

maybe this will help http://www.jatan.net/tsbs/056423.pdf

 

i will agree with the post above.. i have a similar problem sometimes.. i have heard from many people(not around here for some reason) that SOME of the maximas fuel injectors leak...

 

I have a few suggestions.
1) Clean the TB and the IACV
2) Clean, check or replace the PCV valve
3) Fuel filter??
4) Remove both crank position sensors and clean the fine metalic dust off the pick ups.
4a) Same for the Camshaft angle sensor.

I remember a thread a while back, somebody had the same warm starting issue. It wound up being the ignition switch. I don't think that part is that expensive, might be worth a try replacing that, it's a known failure item.

 

i have the same problem