Good evening all. I'm new to the forum. I recently discovered it while working on my daughters 1988 Bronco II 4WD. My wife drives a 2004 Expedition. I recently sold our 1974 F100. And I drive a 1998 f150 4.2l AT 2nd with about 250k on her.

This post is with regard the the F150. I had the engine replaced at 140k mi with a 60k mi, 1999 motor about 6 years ago due to hydrolock. The mechanic did not educate me as to why this happened. So, I thought it was just bad luck. The replacement engine was solid though until recently, when I started noticing coolant loss, occasional rough idle, loss of power and rich exhaust in the mornings a few weeks ago. So, I just kept topping off the coolant. But could never see a leak. About a week ago, the engine suddenly missed really bad, lost power and made a muffled thump a couple of times. Then seemed to run oddly. I aborted the trip to the grocery and eased her back to the drive way. I spent the evening reading forum discussions and watching YouTube videos. All signs pointed to the lower intake manifold. So, the next day I pulled the plugs and turned it over. Sure enough, coolant shot out of the #4 cylinder. It's a good thing I studied up a bit before I went out to start it. Or, I might have hydrolocked it. So, I figured I might get lucky and just need the intake gaskets.

I removed the plenum and manifold and replaced the gaskets. While I had it apart, I removed the serpentine belt and turned the crankshaft a few rotations. It rotated smoothly through all cylinders. I am a driveway mechanic with no specialty or diagnostic tools in my personal arsenal. But, I have enough to complete the gasket job and can borrow what I need for more in depth work. I also couldn't find my Haynes manual, but it wasnt that complicated to do without it. I did a pretty thorough job of cleaning everything and meticulously putting it back together. I gambled a bit and decided not to go further than the IM gasket into the motor thinking that if it requires additional work, I won't be out too much $ if it needs head gaskets or more. I can do the upper part in about half the time when I don't have to figure it all out again.

Now after getting it all back together, she turns over, but will not start. I'm getting spark at the coil pack, the fuel pump whirls when I turn it on and starting fluid doesn't do the trick. If there's no fuel, why didn't starting fluid work if I have spark. I was affraid to spray too much fluid in. Oddly, my dome light, wipers and windows stopped working. I can't see how that would be directly related, but maybe a symptom of the same failure. It was getting late, so I decided to get some rest and advice before digging back into it.

My lists of suspects: 1. Timing jump. 2. Intake plenum actuators. 3. PCM. 4. Piston or rod damage 5. Some kind of vacuum leak or wiring failure brought on by disturbing everything. 6. Coincidental sensor failure (which ones, I'm not sure).

My very active and creative imagination has scripted this explanaition: coolant has been leaking into #4 for a while. One last time over the bridge the other day and the gasket opened up too much. Enough coolant got into the cylinder to give #4 a really hard time. Meanwhile the upper end tried to spin on, causing the timing chain to jump. This may explain the thump coinciding with hesitation followed by rough idle and erratic power. But, then again I have an active imagination.

Tomorrow, I will check for fuel pressure at the rail valve, check for spark at the plug ends of the wires, and inspect the hoses and wiring carefully. I'll also track down my manual. Hopefully, I'll figure it out.

If anyone has some insight that they would like to share, I'm all ears (or eyes, I guess). Am I on the right track with my approach? If I am going to buy or borrow tools to run more diagnostics, what do I need? My terminology is lacking in that area. So, please correct me if I call something by the wrong name. But, I imagine I need: cylinder compression guage, fuel pressure guage, electrical meter, timing light.

Thanks in advance for reading this far and for any worthwhile advice. I'll post my progress.

 

To boil your story down, if you have spark it's not the PCM.
The lights and wipers are not involved in running the motor in any way.
You have some other issue for that.
Do the following;
Test fuel pressure at the test port with a gage. What is it after several key on cycles?
Next did you have the camshaft drive out? If yes, did it get put back in proper timing, because it control fuel injection.
Next, is all the harness and connectors plugged up?
Good luck.

 

Thanks Bluegrass. I didn't get back out there under the hood yet due to the frigid weather. It actually snowed here in NE Fla yesterday! Made me miss living in KY. The cold weather gave me an excuse not to do lots of stuff.

I did not remove the cam. Just removed the intake. Cranked the engine by hand through all cylinders, just to see how it felt. Not very scientific, but they all felt as I imagine they should. I plan on getting the right guages and and testing fuel pressure and compression. After I check for more obvious things.

I'll post my results.

 

Check to make sure it is wired right.
Either this or fuel pump has croaked is my guess.

 

fuel pump could have pressure and the main electric wire harness feeding the injectors could be loose so no injectors working.

 

Well, better late than never. After a year of procrastination between half hearted tinkering, I went out to give it another look and she started right up! The truck ran great for a few minutes and then died and would not start. I ran it down to a bad fuel pump. I could still hear it whirling when I turned the ignition on, but it was not delivering fuel. Starts and runs fine. Now I just have to figure out why the oil pressure drops when I stop after it is warmed up.
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Change Oil and OIL FILTER. Just do it. I went thru this on a '97 F-150 4.2L. I'm also a Okay mechanic and I went thru a who sceniro of no oil pressure. I had a mechanical test guage hooked up as well. I change the oil and oil filter and "boom" now I have oil pressure. I'm not gonna try to explain why, as, I was just glad to see it come back and leave it alone at that. bjr

 

Well, started simple and went ahead and changed the oil. I only had about 50 miles or so on the oil I put in after the IM gasket replacement. I also replaced the oil pressure switch. The oil came out pretty dark for being so new and the oil filter was heavy even after draining all of the oil out of it.

The oil pressure registers a bit higher now and has not dropped the way it was doing before. Although, there were a few minor fluctuations.

I actually bought a bottle of engine cleaner, but thought better of it after some research. I was affraid of unleashing too much sludge. I figured that I would replace the filter again and then another full oil change and hope for the best.

Thanks to those that have chimed in on my posts. Hopefully, this thread will be of some assistance to others along the way.

 

Update: so, I changed the aftermarket oil pressure sensor to a Motorcraft. Also, replaced the Purolator filter with a Motorcraft and replaced the PCV. No fluctuation in oil pressure at all thus far.

 

Sounds good, excellent work. bl2009