98 4.0 sohc explorer died in operation

Hello,

I own a 98 4 litre sohc explorer sport. Just after a short drive today, the engine died on my way home. It will not start.

I had a tune up done recently as well as a new muffler, belt tensioner and idler pully (bad bearing). There has always been a problem with cold weather affecting the idle state of the engine. I can keep the block heater plugged in and it starts fine with 5w 30.

would a diognostic tool work while the engine is off?

could the problem be something that a diognostic tool can't read?

should I replace the iac valve and gasket or simply clean it?

Welcome to the forum!

When you say the engine won't start, we need more details. Does it crank but won't fire, does it just make clicking sounds, does it sound like it wants to start (sputters), will it start if the accelerator is held partially down? Were there any symptoms leading up to this (other than the cold weather idle issues) such as rough idle, stumbling, etc.?

The cold weather issues could be coolant temperture sensor or idle air control (IAC) but shouldn't prevent the engine from starting. If the IAC is completely closed, then holding the accelerator slightly down should allow the engine to start if the IAC is the issue.

-Rod

thanks for the response.

the engine cranks (starter moter turns and fuel pump turns on) but it still wont start. Could it be a crank sensor? I tried pushing the accellerator down and still nothing. thanks again.

Well, the next step would be to determine which you don't have of proper air/fuel ratio, spark, or compression. Of these, the easiest to check for is spark. I think your '98 has the coil pack, so you will want to use a spark tester, don't just hold the plug wire near the block (hard on the coil packs). If you have spark, then your crankshaft position sensor is working, next would be to check for fuel. After cranking the engine a few times, pull a spark plug or two and see if they're wet. If not, then you probably don't have fuel. Or, if you have a fuel pressure tester, use that to check for fuel. If you don't have fuel, then check the fuel pump inertia shut off switch located behind the passenger kick panel trim piece. If that is not tripped but there's no fuel, you'll want to investigate a fuel pump issue and fuel filter.

If you appear to have fuel and spark, then check for broken or cracked vacuum hoses, loose air intake tubes, disconnected sensors, etc.

And to answer your earlier question, if the instrument cluster bulb test completes when you first turn the key to the run position, then a scan tool will work even though you can't start the engine. This would be an excellent thing to try if you have access to one. I don't know if the chain auto parts stores loan them out since you can't drive there.

-Rod

Thanks again for the advice. I tested the spark plug, and there is a good amount of spark. I also replaced the filter, there was dirty gas out one end but clean and free flowing gas out the other, so that is most likely a non-issue. I do beleive it is probably something to do with the injectors not receiving any fuel. I would find it hard to believe that all injectors failed at once, so I am inclined to believe it is the connection(s) between the pump and the injector or just a very weak pump. The inertia switch has not been tripped, I did however unplug it when I replaced the fuel filter to avoid any spillage I plugged it back in and ensured the red button was depressed.

The obd2 reader costs $140 and I am unable to rent one from any known source (canadian tire, part source).

I am going to eventually tow it to a local shop. I'll let you know the outcome so that others experiencing this problem can resolve this issue on their own, possibly.

Thanks again Rod for all your help and advice.

i have a 99 explorer sohc that died in operation. THe timing chain tension broke. Is there an easy way to set time as i can not find any timing marks. Thank you

As it turns out the problem with my engine was not the timing tension at all. I just received a call from my mechanic and he told me it is a dead cylinder (#5) a compression check was done and he figures it is a broken valve. So much for the easy fix.