cranks, won't start without starting fluid

[joecrna]

My reasonably stock 1998 SOHC will intermittently fail to start. It cranks normally. Everything seems fine, she just doesn't start. This happened once 6 months ago and now twice in the last three weeks. This always says to me one of two things. Fuel or spark.

I wish I could say I found a solution through proper reasoning and good trouble shooting, but I just stumbled on it because I was frustrated and in a hurry. When it would not start 6 months ago i took the intake apart and eventually, out of frustration, shot some starting fluid into the intake. She fired right up and continued to run. I put the intake back together and she still started up with no problem. The last two times, I simply removed the PCV tube from the boss in the cold air intake tube and shot some starting fluid into the air intake tube. Stuck the PCV tube back in place and it started up immediatly. No stumble, no stall, no further problems. Even restarts again easily after immediate shut down.

Clearly there is a problem and my girlfriend is now afraid to drive the Explorer for fear of getting stranded without me being nearby to help. It seems that some sensor is not telling the computer the truck is trying to start, as once started it continues to run without problem. No codes are triggered. Any ideas would be much appreciated. Taking it to the mechanic now would just result in multiple parts being replaced, lots of money wasted and no solution to the starting problem. Any thoughts?

 

[2000StreetRod]

Cold or warm start?

If it does it when attempting a cold start I would suspect the engine coolant temperature (ECT) sensor. The PCM receives the ECT from the sensor to determine how much to richen the mixture. You're having to richen the mixture manually to start the engine. One of BrooklynBay's useful threads contains a resistance vs temperature table to check the ECT sensor.

 

[96explo]

Check the fuel pressure, change the fuel filter and possibly the pump. If pressure is low (on the fuel pressure gauge) after cycling the key off, on several times without turning over the starter and trying cranking it you need to plan on getting a new pump soon! I used the actron CP5102 ($10 on ebay) 5/16" red tool in this pack to swap my pump, hopefully yours will not need it. I used the fram G3850 fuel filter from walmart, $8. If you don't have the fuel pressure gauge you can get them from harbor freight tools for about $16. Are you getting any odb2 check engine codes?

 

[joecrna]

No codes. It does it on cold start 2 of 3 times. The other, it did sit a couple hours. I'll test the coolant sensor. The fuel filter is reasonably new and it continues to run after starting with starting fluid. It does not lean out or stumble approaching red-line under wide open throttle so I doubt the fuel pump, but I will check the fuel pressure prior to cranking just in case.

Thanks for the replys.

 

[joecrna]

Coolant temperature sensor replaced with leaking housing. No more starting problems. How much do I hate computer controlled cars?