The computer will remember nothing of the 1st engine if its been disconnected from power for any significant amount time.....assuming its a factory puter we're talking about
yes I know that.... that is not what I am asking. I had fuel injection issues with this thing that I thought I had resolved, shortly before I swapped a completely stock rebuilt engine in there, and am wondering for one thing if the failed, fresh engine had anything to do with the prior issue. or if the issue I discovered with the heads, caused the computer and fuel system to react how it did.
OK get your popcorn or beer or Raisinets or whatever your favorite "movie food" is, here's the story.
I bought this 01 Durango about 6-7 years ago, with 214k miles on it. It had the highest of miles of any vehicle that I have ever bought. Yeah, I know a lot of miles but it was all "road miles" and it was a southern vehicle, very clean and rust free. It had only been in the Chicago area for a month when I got it. It is the 360, version but not an R/T. Upon buying it, I immediately did a full tuneup, replaced all belts and hoses and more preventive maintenance type repairs.
It did us great, including trip to Houston and back, serving as my wife's daily driver, and pulling my camper a couple of times in between, until it got to about 250-252ish K miles, when I started getting a chronic Cyl 6 misfire. At first it would only show up as a code, but it never "felt" like it was running bad at first. I did a complete tuneup at that point, using premium grade parts, (cap rotor wires, plugs, PCV and air filter) and it persisted. again, it didn't run like it had a miss at this time. I took the injectors into a Bosch certified fuel injection place that deals with both gas and diesel injectors, to test, flush, and rebuild them. Was told they "needed a good cleaning" but were all otherwise fine. and flowing equally.
STILL had the misfire code.
We just drove it a bit more, because it ran fine. Then it started running bad, as I remember. Its been 3 years ago now since then. I did a compression test and all cylinders on that bank were still around 150-155 PSI. Pretty good for an old engine. I tried swapping spark plugs, injectors and plug wires to see if the misfire would "follow" any of those parts to a different cylinder. It remained on cylinder #6. so I sent the computer into a place that reconditions automotive computers that was recommended to me, for diagnosis. and I went thru the whole wiring harness looking for trouble there. None found. The computer came back "repaired" as they had apparently found reason for my misfire in some loose solder joints.
By now the oil pressure was getting low ( 258K (HIGH) MILES!) and the engine was starting to get some bottom end noise. THAT'S the reason that I went and found another engine/ which I treated as a "core," and tore it down, sent the block and crank into the machine shop for all of the necessary machine work, bought all new pistons, bearings and rings to match the machine work that was done, bought the new heads, took them out of the box, and bolted them on the fresh engine. all while still driving it as needed, got 2nd engine to minimize downtime... or so I thought.
The engine that I bought and rebuilt, was out of another 2001 Durango. Identical replacement.
I also replaced the cat converter, the fuel pump, the muffler, both O2 sensors, and ALL tuneup parts (again) along with the rebuild, AND rebuilt the transmission at the same time with a reman tq converter installed, at the same time. I was setting this rig up for the "long haul" and I must say now, if I hadn't yet/ that all work done, all parts replaced were "stock replacement" (though most were bought aftermarket) and that I didn't "cheap out" on anything, and bought the best grade available of those parts on which there was a choice. Nothing was "modified".
I also went to the junkyard during this, and found another 2001 Durango 5.9 computer and when plugged into mine, it would only start/quit/ start/quit start/quit. the damn SKIM system. I hate computers. So I sent the original computer and this one back to the rebuilder, and asked them to recheck the original, or else to ONLY program my VIN into this replacement computer. "Please get me ONE good, functional computer" They did both, saying that the original computer repair needed a redo, that they were sorry about any problem, that the original tech that worked on the original computer from the Durango "no longer worked there" as they made it sound like they had had "issues" with that person and the work they had been doing.
They returned both, having done as I had requested, "no charge" saying that they "ran them on a test vehicle on site" and they were "working as designed" they sent these computers back both with a "lifetime warranty" and recently I called them and asked, they said they'd recheck their work "no problem" if I send them in/ IDK if I can trust the original one anyways, having been into "for the same issue" twice now. Initial computer rebuild, was shortly before the engine rebuild. both original and junkyard computers stacked on workbench currently collecting dust.
When I initially got the rebuilt engine into the Durango, it seemed to run fine, while idling in my garage, while I ran it at "break in" RPMs/ I put new lifters in during the rebuild, but the original cam that this engine had come from the factory with. I ran it to temp that night, set SYNC, then let it cool, repeated that the 2nd night, the 3rd night I started it up and let it warm up, then decided to take it for its maiden voyage.
It went poorly, to say the least. I live in the country so I can drive "however," as conditions warrant. so I tried to build up to 60MPH. Accelerated normally, no "holeshots" or anything like that. I never made 60MPH. I think I got to 50 or so during the whole 4 miles it ran. at this time I put it to the floor to see if that would help, it didn't. it topped out at 50, and was losing that.... It ran like I would expect one with a weak fuel pump to run. but the fuel pump was replaced upon the engine rebuild, and once I got it home and started evaluating things (the next night) I tested fuel pressure and it was dead nuts on spec.
On the test drive... pulled out of my subdivision, went ~300 yards, made left turn. for the 1st 1/2 mile, speed limit was 35, so I didn't get crazy. at 1 mile is a STOP sign. After leaving STOP sign I tried to get up to 60, never got there. at 2nd mile I made a left turn. died. started right back up. went 1 mile. went to turn left again. Died again. Wouldn't restart. Called my son for his truck and a tow strap. Was looking around under the hood while I waited for him. Was dark out, was easy to see the whole underside of the Durango ahead of the muffler glowing cherry red. and yes I melted the cat. I looked thru it before I installed it, and again after I removed it, in prep to pull the engine again, and it was a melted blob. not just "lit off"...
I got it to start the next night, I plugged in my scanner and I don't remember all of the parameters, but one that I do remember, was having an injector "on" time of 17.some milliseconds at idle, when I was expecting to see around 3-4 milliseconds. At this point because I had been "everywhere else" on this engine, I went to a junkyard and found an intact looking wiring harness from another 2001 Durango with the same engine as mine has, bought it and installed it. tried running engine, no change. "grasping at straws" at that point, would the long "on" time be a result of the stuck valve, or because of the clogged exhaust, not being able to breathe at that point?
and the reason that I decided the engine had to come out again was that at this point I drained the oil to do the "break in" oil change, engine had 2-1/2-3 hours on it at this point. and it came out as a silver slurry like I have never seen, fresh rebuilt engine or not. This was NOT my 1st engine rebuild, probably (at least) my 10th. and I have done my son's 360 since, with no issue.
at this point I was pissed, put it on the other side of the garage (inside), and told my wife to take my 2nd Dakota.... and let the Durango sit. I had to cool off. I had never experienced any of these issues, let alone all of them on one overhaul.
fast forward almost 3 years... I parted out and junked a 92 318 Dakota, which has been my faithful daily driver for the previous 3 years and over 60K miles. Trans issue, something major ate itself, and it wasn't as nice as this Durango is, body showing its age, so my wife and kid talked me out of fixing the trans. so even with 226K miles "I know where this engine has been" and it still ran fantastic with minimal oil consumption, so my initial thought was to just stab this longblock into the Durango. The wife has been on me, she absolutely loves driving it for some reason. and all I see around for sale like it, are rotted out. This one that I have, isn't.
In the meantime I found a 136k mile 360 magnum on CL, out of a 2000 Durango RT (yes I know the RT means nothing about "hi perf" with that engine, vs the one in my SLT, I have seen that come up over the years, the Durango that this engine came from being an "R/T," is nothing but a coincidence)
I bought this engine, and decided to re gasket it while it was out, as a preventive maintenance precaution before I stab it in, and decided that as long as I pulled the heads "anyway" to replace the head gaskets "while I had it out," I wanted those new heads on this engine that had cost me $700 a few years ago. $700 is a lot of money to me. To some it may not be.
It wasn't until I went to pull that new set of EQ heads/ with the intention of putting them on this short block, that I did anything with the Durango, or the engine that I rebuilt for it, since the initial job went to $#!t. and while pulling that set of heads, first I discovered a badly bent #4 exhaust pushrod. Then I found the #4 exhaust valve "hung open" when I pulled the valve covers.
I got the heads off and discovered a witness mark on the #4 piston and aforementioned exhaust valve bent. I also discovered, upon pulling these heads back off, that the valve chambers in cylinders 1,2,3 look like a set of heads that had been bolted on and pulled right back off, without having been run. Valve chambers on cyls 4-8 were blacker than coal// and obviously had been fed way too much fuel.
I have never had to deal with sticky valves on a car or truck I have had a couple of tractors that came to me with stuck valves from years of sitting outside before I got them which I had to free up in order to get them going, (mostly Kohler, single cylinder cast iron) but that is different from this situation.
I will add at this point, that I am a fleet mechanic for the State of Illinois, have been for 6+ years, and was an alignment/brake guy for ~20 years before I got this job, I deal with cars daily. Not my 1st rodeo.
I still have the original engine that was in this Durango, sitting on a dolly in my garage too. All that has been done to it was to pull the right side head for a quick look to see if I had a sunk valve or something. so I have the original engine, the one that I rebuilt, and this one that I just bought off of CL that I am getting ready to drop in there, so that we can drive this thing for the 1st time in nearly 3 years. I have plans for that original engine, and the failed rebuild too, depending on what I find when I get it back onto the stand. My son wants to build a "stroker" out of one of them.
so after all of that, (which was asked for, so I answered) this is partially a "chicken or egg" kind of inquiry, am wondering if the sticky valves/ and the resultant delayed closing/ bleedoff of compression, had anything to do with the computer dumping so much fuel, because of what the computer might have "seen," or if there might be "something else" going on.
I DO NOT WANT and CANNOT AFFORD a repeat. Those damaged heads are at the machine shop, I was told by the machine shop, upon their teardown, that they were "set up from the factory" with all of the stem to guide clearances, too tight. They had to pound out all of the exhausts once they had the springs off. I'm finding more and more reports of the same problems with EQ heads, mostly from right around the same time frame that I bought that particular set of heads and put them onto my engine. which would have been Oct of 2016.
the hope is that I get this other engine prepped and installed and wired up, that this was the extent of all the problems, that they were "all" caused by the too tight valve clearances, and NOT some other underlying issue.
This Durango will be with us until it rusts itself into the ground. I almost bought a 2018, Hemi, 1500 reg cab with an 8' bed recently..... but walked away when I found out that I would be on the hook for 7 long years. I had always said I would never again do a 5 year loan/ as I had done in the year Y2K on my Wrangler..... so if I wont do 5 years, I sure in the He11 don't want 7 years of payments! This Durango did us well and can/will do so again. My monthly payments are exactly $0.00 and will be as long as I own it. as is the monthly payment on all of my vehicles (this happens to be the newest by "model year" only... next closest, and it happens to be my most recent purchase is a 99 Dakota) I want a rust free square body D/W series truck again.
Even if they were "free", I do not like newer vehicles. Too costly, too much plastic and too much "offshore" content, not enough steel for me. Working on newer vehicles makes me appreciate my 78 Sport Fury that much more. seeing 2010-13 F150s at work, with so much rust already, sure doesn't inspire me to go buy anything that new.
I would appreciate some "general" talk about "how a computer might react" and what the sensors might be seeing, to cause the computer to react such a way, with various mechanical engine issues.