Fire, fuel, and compression, all at the right times. Figure out what you don't have through the process of elimination. Fuel is easiest to check, see my previous post for checking fuel pressure. Gauge kit at Oreilly's for free. Bad CPS turns off the injectors, you can squirt fuel in to the engine manually and it should sputter if you have spark. Or get the spark plug tester at Oreilly. With fuel and spark you shoudl at least get a sputter or pop. Do those test and report back.

 

Sounds like a backfire. Are your ignition leads on the correct cylinder spark plug?

 

Turns out it was the fuel pump in this case. I started a new thread "2004 DII died on the highway" and I'll post what I did and how I did it there.

 

Thanks for closing out the thread.

 

This thread is still open!

Sorry my efforts to revive my Rover are few and far between lately.

I have previously confirmed I have fuel pressure at the rail, and I have spark at each of the spark plug leads which are correctly ordered.

The CPS was replaced last year and again after this incident but the new one didn't make any difference.

Where should I be spraying starter fluid in to get the best chance of ignition? I have tried starter fluid to no avail.

I'm currently working my way down to the valve seals to check them, but what should I look for? Will it be obvious if they have failed?

Lastly, when this all occurred the wire cluster holding wires to the injectors, oil pressure sensor,etc was melted onto the exhaust manifold and many of the wires were sitting bare on the manifold. I've since repaired these breaks in the wires and spliced connectors as needed but could this have possibly shorted something in the ECU or sent my adaptive values into oblivion and need a reset? I've thought since the beginning this may be a big key in the mystery but am unsure how...


Also a recent finding. My intake plenum gasket was mistakenly thrown out during my repair and the old one was used. I noticed there appeared to maybe be coolant around three of the cylinder holes on the gasket. Could a failure of the intake plenum gasket cause this sudden failure?

 

This is getting confusing; I think massarst injected into this thread but I Brake For Cats (op) hasn't followed up recently.

Anyway, to the op: valve seals don't have anything to do with anything at this point. Valve SEATS were mentioned at some point. You do not seem to be attacking this with any kind of logic; you're all over the place. It's hard to help when you're asking questions before addressing the advise that has already been given. Get into this thing. You'll get more info on the issue by inspecting things, then we can move on from there. I think the last suggestion was to pull the valve covers to see if all of the rockers are moving, to check for a bad camshaft or timing chain. After that, pull the heads and check valves and seats since you said you had low compression. I could be wrong tho, this thread is kinda hard to follow..

I might suggest getting some fresh eyes on this from someone who knows these trucks. Maybe find a good independent specialist, or someone from the group who is willing to help, and is nearby. If I'm off point here, I apologize. Just trying to steer you in the right direction and save everyone some time and effort.

 

About melted wiring (pretty important detail), shorting out a voltage can cause high current, and high current can damage components, if they are not protected. The ECU for example provides voltage outputs to the TPS and MAF. If those voltages are shorted, the ECU could be damaged, unless they are protected from short circuits. I don't know if these Rover ECU outputs are short circuit protected.

 

Thank you for addressing the wiring. Do you know if these wires are able to be checked using a voltage tester and what sort of ranges I should look for?

I'm sorry this thread has become so scattered. Between multiple people injecting their own threads into mine resulting in many of my questions going unanswered, and being asked repeatedly the same questions (did you check fuel? Did you check spark, did you replace CPS? Yes, YES, YES!)

I've resorted to asking the same questions again due to this. Others have gone back and forth on whether it would be seals or seats but nobody is addressing my question of could these cause such a sudden, absolutely silent failure.

To bring this thread into a funnel, you are probably right on telling me to just check the damn valve seats. I do have low compression in all cylinders unless I add oil into it before cranking so this seems logical. I guess I'm reluctant to accept this is the answer because I'm worried about what caused them to fail if this is the case. If the valve seats all have such a complete mechanical failure, is there a bigger problem?

Or did I fry my ECU and now the car can't make any sense of itself.

I appreciate the help. I refuse to take it to a shop, I'm not new to the Rover game and can manage any repair needed but this diagnosis has my brain pulled so many directions.

 

"I appreciate the help. I refuse to take it to a shop, I'm not new to the Rover game and can manage any repair needed but this diagnosis has my brain pulled so many directions."

Very understandable, they can easily boggle the mind.

When exactly did the wiring issue happen? Before or after the "silent failure"? If it was running fine before the engine stopped running, then it wouldn't likely be the problem now. It sounds like you had a mechanical failure and I would just start digging until you find it. To me, the seat issue seems pretty rare but could definitely cause the problem. It's more likely a cam or timing chain issue which, like I said, can be easily checked by pulling the valve covers before pulling the heads to check the valve seats. Only way to tell for sure is to get into it. If you'd rather try another ECU before doing engine work, get a used ECU and try that. Unlikely, since you said you have low compression, but you have to start somewhere.

 

What should I look for when I remove the valve covers exactly? I'm in the process of tearing into it currently. I will look for a new ECU though since that could be a possibility.

The wiring harness meltdown was discovered while checking the engine after it died silently. I had about 3000-4000 miles on it after doing the head gaskets and presumably the wires were on the exhaust manifold the entire time without me noticing. When I saw it, all the tape wrapping the wires was melted off and numerous wires were stripped bare, and a previous splice to the oil pressure sensor was melted to the manifold.

Could a failure of the ECU cause the engine to run so incorrectly to put the timing off and cause the low compression?

It's my understanding that a broken timing chain would be audibly noticable either at the time of breakage or during cranking, is this true? It sounds healthy while it cranks.