Thanks in advance for any and all help...

1997 Discovery SE7 4.0 GEMS W/AES
180,00+ miles, impeccably maintained, AMSOIL since 15,000 comes out still amber after 7,000 miles.....

Was running well, purring like a kitten. However it was getting progressively weaker. I run over-sized tires so gutlessness has been with me for years and years....Anyway, I decided to do a compression test to see if I had a problem. Test was okay (a bit low but generally even) all cylinders were around 110 psi. A wet test showed minimal gains of about 5lbs. but still even.

Recently replaced injectors and put 100s of miles on her after that. New MAF recently. new plugs and wires, fuel pressure @ 38lbs.and stays for hours. Spark is present (each wire checked with timing light).
NO CHECK ENGINE LIGHT!!!

Back in the day with all of these parameters I would chase ignition timing, but that is CPU controlled on this truck.

So, I have spark, fuel, compression, timing and it drove and ran beautifully to where she lies.....took out the plugs and now.... NUTTIN'

I have tried everything I can think of.....

PLEASE, someone come and tell me how dumb I am and that I should plug in some wire or something.....SOMETHING....

 

Does it crank and not start? Did you check fuses (both boxes)?

 

Walt,
Yes, it cranks but does NOT start. I have fuel pressure at the rail, timed spark. and adequate compression. And, Like I mentioned, I drove it there and it was running beautifully.

I am wondering how I can tell if the injectors are feeding fuel. However, when I pull the plugs they appear to be wetted.

I just double checked all fuses are good. CEL ON in run position and off while cranking...

I placed a piece of cardboard in front of the open plug ports and cranked for 10 seconds...the cardbnoard had a faint spray pattern BUT not enough in my opinon. I would think it would be soaked or at least quite wet....I am thinking I am NOT getting injector pulses....

Does anyone know of a way to test the injector impulse???



.

 

did you save the old injectors ?? just plug one in to see if it is actually getting fuel...
when you did the compression test did you pull a fuel pump fuse or otherwise un hook the pump while you were cranking the engine over ? ...I'm not absolutely sure about this but I believe that if the ecu doesn't see spark it will kill the fuel pump....If youare convinced you have good spark....you could feed it some fuel from a squirt bottle either through the throttle body or at each spark plug just to hepl the diagnosis along.....

 

Xcellers, Thanks..

the fuel pump IS online and supplying 38 Lbs. of pressure.

While cranking each cylinder shows spark as seen through a timing light hooked up to each wire in successive cranks. I have also laid random wires on the top of the engine, grounded them, and cranked, they showed timed spark.

I have placed a piece of cardboard in frond of the bank of open spark plug ports and cranked for 10 seconds for each bank and am not showing any substantial fuel vapor marks...This leads me to believe the injectors are not sending a pulse message to the injectors...The injectors are new and were performing for hundreds of miles before this test. to swap one out for ****s and giggles is quite the investment in time as the entire phlenm must be removed...At least that's how I did it when I replaced the injectors a month ago...I saw no short-cut for that job..

 

im not suggesting this but maybe try just a hit of starting fluid see where that gets ya.

 

im still learning

this might help?

https://landroverforums.com/forum/di...-things-29347/

 

....not swap anything out at this time.....just unplug the wire connector from any one of the injectors and insert one of the old injectors into the connector you just unplugged....let the injector just lay on top of the engine long enough to crank the engine over and see if fuel is squirting out the injector....just a quick check to see if that is the issue

 

Xceller8, Great idea..I did that (with a fuel hose from the rail schrader valve and YES I do have fuel pulses....

Now, I have compression, fuel, spark and the only thing left is timing....Since the ECU handles the timing via the crank and cam position sensors, that should be handled...

NOW!!! I am wondering if during the compression test with all the p[lugs out except the tester if the timing chain skipped a tooth with the lopsided compression impulses caused by the test????? I did hear a funny sound during one of the test (the wet test session) that sounded like my starter drive releasing from the flywheel and since I was spinning up the starter pretty hard, I figured the starter was just getting hot and the drive let go for a second or two....

I am going to mark my harmonic balancer and my timing cover and check my timing against TDC on cylinder 1. if it is about 3\8 inch (8mm) before the line I should be okay if i am an inch or more away I jumped a tooth on the cam chain.....I kind of glanced earlier and didn't see any official timing marks....It would figure there would be none as the timing is adjustable...

Thoughts???