Hello, and I need some advice. I own a 98 xc and lately its been giving me more trouble than usual. After the car sits all day it won't start without lots of attention and cursing. Here's the facts. Good spark, fuel pressure on rail is 41 psi (not too bad), sometimes the cooling fan comes on after sitting all nite when its 20 out, And will start almost right away with starting fluid. Fuel pump seems ok, gets up to 41 as soon as key is turned. Could it be coolant sensor or maf sensor. I don't have a way to pull up codes,so I may have to break down and spend some cash.This ones driving me crazy.

 

Could very well be a coolant temp sensor.

Have you let the car sit overnight with the guage on?

If so does it drop all the way to 0?

Try turning the key on and off a couple of times before trying to start and see if that helps.

 

Tech,
Thanks for your reply. The preesure guage will drop to zero overnight. But will pump right up in the morning when key is turned on.with no dip in preesure when start is attempted. This morning I went out, it was 10 degrees, car sat all nite, pulled the mas sensor connection, and the car fired right up(like new) let it warm for 2 minutes, shut it off, replaced the maf connection, and it startes fine again. Maybe maf went bad and telling module to lean out the fuel, so cold starts are tuff. May pull sensor tonight and look to see anything out of the ordinary. Thanks, jack

 

Sounds like you might have tracked it down.
Try cleaning with Brake clean if you have any.

Also the pressure should hold at about 15 PSI overnight.

 

so maybe the pump check valve is leaking by, may be not a 100% connection on guage, may be losing vacuum. Oh, and now the car wouldn't reproduce a start with the maf sensor disconnected. In the am, i'll try temp probe disconnect. Open the circuit, should tell ecm that motor is cold. I may have to go to advance auto parts and burrow the scanner they have, thanks again

 

Let me know how it goes.

 

problem solved, looks like it was the temp sensor on the engine. It's hard to believe that that 22 dollar part plays such a large role. This time I got away cheap. Thanks for your help tech. jack

 

Anytime