98 4.0 won't start! Help!

[RayInStl]

Hey guys, new to the forum. A buddy of mine was looking for a first car but is strapped financially, so I loaned him some money to pick something up. We came across an Explorer on Craigslist that was running as of a couple days ago, but died while driving. It was going cheap and I thought it would be something simple like a fuel pump or sensor, so I bought it sight unseen for $300. My budget was $1k, so I figured we could use the other $700 to get it running.

I work on my own cars, so I'm usually pretty good at diagnostics, but this one has me scratching my head. I asked over on therangerstation.com since I'm already a member there (I have an 83 4x4 Ranger with a 2.3L). I'll explain what I've done and what they've suggested so far. But I thought I'd ask here in case there was a known Explorer only issue or if you guys had any other ideas.

Vehicle history
The car ran fine 2 days ago. It was owned by the same family (the previous owners) since new. It was being driven by their teenage son when it died while at speed. He was able to get it off on the shoulder. The wife had been trying to get the husband to get rid of it for years, but he was sentimentally attached. This was the straw that broke the camel's back, so he listed it on Craigs List. I bought it and pulled it to a nearby parking lot to check things over.

Vehicle info

• 1998 Ford Explorer 4x4
• 4.0L SOHC
• 215,000 miles on odometer
• Cranks, but doesn't start. Does not even try. No sputter.
• "Check Gauge" light is on
• CEL is on. Has the following codes:
  • P0301 cylinder 1 misfire
  • P0303 cylinder 3 misfire
  • P0304 cylinder 4 misfire
  • P0305 cylinder 5 misfire
  • P0306 cylinder 6 misfire
  • P0171 system too lean bank 1
  • P0172 system too rich bank 1
  • P0174 system too lean bank 2
  • P0175 system too rich bank 2

What it does
When I turn the key, the engine cranks but does not start. The only lights that stay on the dash are the CEL and the "Check Gauge" light (I assume because the fuel gauge is not working). When it cranks, it sounds different than most cars I've had experience with. It almost sounds like the starter isn't trying very hard. Like it's little to no compression.

What I've tried
I initially thought it wasn't getting fuel, so I bought a can of starting fluid and rented a fuel pressure gauge. Spraying starting fluid in the intake did nothing. Doesn't even cough. Pressure gauge shows 40 PSI. At this point, I towed it to my buddies house. While towing, I disconnected the battery to give it time to hopefully clear the codes. When we got to his place, I replaced the battery with the one from my Ranger since the original battery was getting low.

I checked the wiring to the coil packs and to the sensor on the crank for the EDIS system. I didn't see any obvious problems.

Other things that may be important
The key can be removed from the ignition switch at any time. The shifter (automatic, column) indicator is off. When it's in park, it says Reverse. I think the neutral safety switch is fine. It won't even crank if it's not in park or neutral (going by how many "clicks" down I am, not by what the indicator says). Many things on the truck don't work correctly. The back doors don't open at all. The back hatch can be opened only by reaching in between the plastic trim and the tailgate and pushing the mechanism by hand. The lock button doesn't work (unlock does). The key cannot unlock the doors. You MUST use the code pad on the door. That made me think that maybe the security system was tripped, but the security light goes off when the key is in "run".

Any thoughts? The single reply on the ranger station thought that perhaps there was a grounding problem since all of the cylinders misfired except one. Or a problem with the computer since it has conflicting codes. I'm going to be heading back over there tomorrow if I get off early enough, so I'll check the grounds then.

I've been worried that it might have broken one or more timing chains. I understand that the 4.0 SOHC has issues with that. That would also explain loss of compression and the sudden way the engine died at speed. Is there some way to check without tearing the engine apart?

Thanks for any help you guys can provide! They guy I'm helping is one of those people that you really want to help. He's just a really great person. So I'm really hoping we can get this thing running for him.

Ray

 

[2000StreetRod]

check compression

Low or no compression for all cylinders on one bank means the timing chain has slipped for that bank. Low or no compression for all cylinders on both banks means the crankshaft to jackshaft timing chain has slipped.

 

[RayInStl]

Thanks! That's exactly the info I was looking for. I think that's going to be my plan of attack then. I'll rent a compression test kit and see where we sit. It's my understanding that there's 2 chains on the front and 2 more in the rear requiring the engine to be pulled in order to change them all. Is that correct?

 

[2000StreetRod]

timing chains

The jackshaft in the SOHC V6 uses the bore for the camshaft in the OHV V6. There is one chain in the rear between the jackshaft sprocket and the right camshaft sprocket. In the front there is one chain between jackshaft sprocket and the left camshaft sprocket.

There is another chain between the crankshaft sprocket and the jackshaft sprocket.

For the 4WD vehicles there is another small chain between a second crankshaft sprocket and the balance shaft sprocket.

Click on My Helpful Threads in my signature for more than you probably want to know about the SOHC V6.

 

[intelisevil]

With all of your P030X codes, I'd suggest you test out your coil pack. Maybe you're having so many misfires that the engine just can't start?

I was chasing P0303 & P0304 codes for a while and finally found out how to test mine. The part of the coil pack that fired cylinders 3 & 4 was bad.

Look at post #2 in the following thread:

http://www.fordrangerforum.com/4-0-sohc-4-0-ohv-tech/29588-test-ignition-coil-pack.html

With any luck the P017X codes will clear themselves up once you have a running engine.

Good Luck,

 

[RayInStl]

Thanks guys. I'll do a compression test on all cylinders and test the coil packs. Hopefully this evening.

Ray

 

[RayInStl]

I picked up the compression tester and spark light yesterday. We fought to get to the first spark plug, though. That EGR running right in front made it much more difficult than it should have been! We checked for compression on that cylinder and got nothing. I had to stop after that. It's just too cold and windy to be scraping hands on sharp engine brackets.

He's got a garage that needs to be cleaned out, so I told him to do that by Friday. It's supposed to get up to 40 degrees, so working in the garage shouldn't be too bad. I'll have my propane heater with me, too. But it looks like my suspicions are correct. Unless the cylinder has a bad valve or something.

I'll test the rest of the cylinders and get back to you guys. Thanks for the help!