My 98 Died

[zundap750]

Hi all. I'm fairly new to the site. I have a problem and was hoping to find a solution. This seems to be the place to go for advice on all things Explorer. I have a 98 XLT 4 door 2 wheel drive, with the SOHC 4.0. I just finished installing all new timing components (all chains and all gears), rebuilt the cylinder heads, new antiknock sensor, new ignition coil pack, new harmonic balancer, new DPFE sensor, new oil pump, new plugs and wires, new fuel filter, new air filter, and a new battery. I re-installed the engine about two months ago. When I turned the key it started immediately, and ran beautifully. I let it warm up to operating temp keeping an eye and ear out for leaks, or unusual noises. Nothing, it sounded great. After ten minutes I jumped in to take a spin around the block and about 200 yards from the house it quit in the middle of the road while I was accelerating up to the speed limit (25 mph). It just died, no warning no dash lights, till after it was dead, no warning at all. Its two months later and I still can't figure out what happened. It tries to start but it falls short. I've narrowed it down to not getting enough fuel, even though the fuel pump is working. I'm not sure how to proceed at this point.

 

[wood1]

You should start by checking your fuel pressure and leak-down of the pump. You will need a gauge. Do a search and you will find lots of threads on how to do it, or any manual for the ex (Haynes, Chilton's) will outline how to do it. I personally have no experience with the SOHC so this is pretty much all I can offer for advice. No doubt the boys will chime in and help out. Good luck and welcome to the site!

 

[2000StreetRod]

Fuel pressure test procedure

Fuel pressure test procedure

If you don't have access to a fuel pressure gauge you can remove the intake hose at the throttle body, open the throttle plate and spray starting fluid into the manifold, replace the intake hose and activate the starter. The engine should start and run for a couple of seconds. If it does that confirms there is a fuel problem. If it doesn't start then it could be an ignition or compression problem.

 

[zundap750]

I tried the starting fluid, and it did start and run for a few seconds. I hear the fuel pump run when I first turn the key to on and I have pressure at the shrader valve under the hood. Could it still be the pump?

 

[Erik727]

Yes, you need enough pressure to start and sustain running.. Do the test as lined above. I had an issue with mine a few months ago and it wouldn't start until at least 35psi . You should have around 60 if i remember corectly.

 

[wood1]

Get your hands on a gauge dude.

 

[2000StreetRod]

CKP sensor, PATS & FPR

On my 2000 Sport if I use a invalid ignition key PATS causes the PCM to disable the fuel injectors. However, your 1998 does not have PATS so that possibility can be eliminated.

If the PCM does not detect the engine rotating via the crankshaft position (CKP) sensor it will disable the fuel pump. However, that should not happen when the starter is cranking.

Your 1998 has the return type fuel system. Even though the pump is running the fuel pressure regulator (FPR) on the fuel rail could be defective. You might try disconnecting the vacuum hose at the FPR and plugging it. That should cause the fuel pressure to be maximum - at least 40 psi.

 

[zundap750]

I ordered a fuel pressure tester, just waiting on FedEx to deliver it. My explorer does have the pats system. I have the transponder keys. I thought about the FPR being bad but disconnecting it and plugging the hose makes no difference. I have a new fuel pump already, I just want to make sure its a bad pump before I start dropping the fuel tank. You guys have been a great help. I'll check the fuel pressure when my test gauge arrives and go from there. Thanks.

 

[2000StreetRod]

Pats

Does "THEFT" flash slowly when key not installed?
Normal operation

Does "THEFT" flash rapidly when cranking starter?
Try another key
Check PATS fuses

Do you have remote start capability?
Many aftermarket remote start systems can cause starting problems

 

[apolo607]

fuel filter

Did you replace also your fuel filter?

 

[Peanut74]

Based on your post you might also want to check the fuel line in the engine bay to make sure you did not pinch it when you reinstalled the motor.

 

[trodani]

My truck died in the exact same way. Exc ept in my 98 it was a bad altenator, no warning, no noise, nothing. It just stoped running, everything went haywire (my breaks became very unresponsive) and I only figured out the altanator after i had the battery checked. I'm sure thats not your problem in this case, but it seemed odd that two 98's stopped working without warning. <=== remember this is why its important to check your battery and alternator from time to time.

 

[zundap750]

Installed new fuel filter and double checked all lines and wires when I installed the engine. Nothing is pinched. I checked all of the fuses and relays a few weeks ago, all are good. The key I received when I bought it is the one that started it the one time it ran after I reinstalled the engine. The engine tries to start. When I turn the key to start it will spin up like its going to run but when I release the key it quits. If I spray starting fluid in the throttle body opening it will run but only until the fluid is burned. I also removed the IAC valve to replace the gasket. and poured a small amount of gas into the intake and it started and ran but as soon as the gas was burned it quit.