Hello,

Brief history: I bought this 94 last week (4.0L pushrod, 4X4) in a non-running condition as a project truck. I own a 91 Explorer currently so eventually I wish to build one truck out of the two using the 94 as the primary vehicle. My priority is to get the engine running and access it's condition along with the transmission. Previous owner claims truck "just died" towed it home, left it in the driveway and bought a new truck. He thought there was a major engine problem and perhaps a oil pressure issue (we'll see).

What I observed (so far):

Pulled the plugs and they were brutal. 3 Bosh plugs (one with a broken platinum tip) and 3 plugs of unkown brand obviously not designed for an Explorer (gaps about 0.8-1.0). Oil was old, black and viscous.

What I know (so far):

Replaced the plugs, wires and oil. Plugs are firing. Coil resistance OK (primary and secondary) and 40psi fuel pressure at Schrader valve. Fuel relay, pump all seem OK. Voltage to the crank position sensor (CKP) is fine.

I haven't pulled KOEO codes as I can't find my code reader (hopefully soon). CEL light does not come on with ignition on or upon cranking engine (this may be just a blown dash light though).

I'm looking next at CKP unit and perhaps cam position unit.

Engine turns over fine (starter, battery etc) it just won't catch. I'm also not sure about the fuel. Tank indicates 3/4 full but I may try to drain and fill with premium (can't hurt).

Any other thoughs or advice before I get too deep in this engine?

Thanks,

Gil

 

Start with the basics. You've already mentioned pulling codes, go with that. Check to see if you have spark (pull plug wire and see if it will arc on a grounded new plug) and fuel (check rail pressure / existance of fuel in rail) and work from there.

Good Luck.........

 

Spark OK all six cylinders, fuel OK at fuel rail...

CKP next? Voltage to CKP is OK but unit may be shot.

Any other basic checks before I delve deeper?

 

How old is the fuel? Does it have a funny (ie old) smell? Not sure what you mean by CKP. If you mean the Crankshaft Position Sensor, maybe, but since it's firing is suspect that a signal is being generated. Has anything rotated on or around the harmonic balancer that would put the spark timing off? Finding the code reader and pulling the codes would be the best next step in my opinion.

 

In many ways, I agree with pulling codes, especially since the check engine light doesn't come on. Like you said, it could just be a blown bulb. On the other hand, it could indicate that the computer isn't getting power. No power to the computer means the fuel injectors aren't firing. Pulling codes would first tell us whether or not the computer is getting power.

 

Heh. You guys are too trusting. As bad as the engine was, in terms of old unchanged in billions of years oil, I'd be betting the light bulb got oulled just to ignore it!

Pul l the codes and learn to fix the previous owner's newer rides. You'd make a lot of money off him with his ignorance. I guess not changing oil does qualify as "oil pressure issue" and not properly maintaining the engine would cause "a major engine problem"!

 

Obviously, pull the codes. You could also spray some ether into the intake to see if it will briefly run. If so, then you have a fuel problem.

 

Fellas,

Thanks for the responses. I tried the ether in the intake it didn't even cough.

As for getting a deal due to someone's ignorance... that is what I was hoping. The guy also got a company car with his new job so I think he said "to hell with this" and dumped it. I got the truck for $600.00 and it is in solid shape (body wise). I need to do some work on one rocker panel and a boatload of "minor" repairs. I'll do the brakes and suspension too and paint it but if the engine comes around and the transmission is reasonable then I think I've done well.

I'll get back when I find my code reader (damn kids!).

Gil

P.S. I have a 4.0 in my 91 if necessary as well as all the spare parts I need.

 

I hate these EEC-IV readers, just a lot of blinks and beeps.

OK here are the codes (and my interpretation)....

Hard Codes 1 1 6 1 5 9 1 1 4 5 6 5 5 5 8
Continuous Codes 1 1 1 (not suprising as I replaced the battery and these may have been erased).

OK now the fun begins!!

116 - engine coolant temperature out of range (probably, it's 10F up here)
159 - MAF fault (all intake hardware has been removed)
114 - Air charge temp out of range (yeah, it's cold)
565 - Canistor purge solenoid circuit failed (significant or just emmisions "crap" fix later)
558 - EGR valve regulator solenoid circuit failure (hmmm)

Gentlemen, comments? Do you agree with code interpretation?

I need to read up on 558 - EGR issue

 

116 and 114 are most likely because the engine's cold. Shouldn't be the cause of a no start
159 If you say you've removed and uplugged the MAF, then that explains the code. Wouldn't expect an unplugged MAF to prevent it from starting, but ????
565 = open or short to ground in CANP circuit. Again, wouldn't prevent it from starting
558 = open or short to ground in EVR solenoid circuit. Shouldn't prevent it from starting.

Have you tried starting it since you replaced the battery? A few no start faults will leave codes in continuous memory.

It looks like whatever prevents it from starting isn't noticed by the computer. You say it has spark, and it has fuel pressure. Can you hear the fuel injectors firing? Any sign of gas in the cylinders (like a wet spark plug immediately after cranking the engine)?

Any cylinder compression?

 

I agree that none of these faults should prevent the vehicle from starting. I will try a few starts and look for continuous codes. I will also pull the plugs (check for fuel) and do a compression test.

I get the feeling that fuel is not reaching the cylinders although it does not even think about firing with ether down her neck.

Any "common" problems to look for on the fuel rail?

 

Update...

No new codes after attempting to start but fuel is definately reaching the cylinders. I'll try a compresion test tonight or tomorrow (it's cold out there).

 

Definitely check the compression. Be sure to check at least several cylinders and thatat least one is a back cylinder (in case of a broken cam shaft). It's starting to sound like some kind of timing issue (jumped chain, broken cam, sensor off position, etc.) I'm not sure about the disconnected MAF either. It may not stop it from running, but it sure won't help. I know on my '92, it will run at least for a while without the MAF getting any air through it, because I've run it while spraying throttle body cleaner into the intake at the butterfly valve so the hose was disconnected to get to it.

 

I'm with you on this. It sounds more and more like a timing problem. Hopefully a sensor (crank or cam) as opposed to timing chain, camshaft etc.

I also agree that the MAF should not be an issue on start-up. I removed the intake hardware to more easily get at the engine. I would still expect a start or rumbling/coughing with the MAF disconnected. It won't run smooth without it but it will still catch.

Since I need to remove all 6 plugs to complete the test I will check compression at all 6 cylinders. The specs on this read "lowest reading within 75 psi of highest reading (100psi minimun)" so checking them all seems appropriate.

It's -27F with wind-chill out there so this may not happen today!

Thanks for the input.

Gil

 

Hello,

I got to "check" the compression today. Although the adaptor for the compression guage I own did not have the proper coupler for the deep threaded (Explorer) plugs I did get to do a basic cylinder check (no exact pressure readings recorded). Five of the six cylinders have reasonable and equal compression but number 6 cylinder has (virtually) ZERO compression. I also noticed oil around the head and valve cover of #6 cylinder.

My project truck is going to be more of a project than I initially thought.

Any comments, ideas, methods to procede?