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  #21  
Old July 20th, 2015, 11:03 PM
psykokid
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Jake
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If you have the part number for your ECU I can check the two spares that I have if one is the same part number yours. IIRC you have to have someone with a testbook or equivalent put the ECU into learn mode so that it syncs with the alarm module.
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  #22  
Old July 20th, 2015, 11:20 PM
Departing90
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Yout cateletic converters or converter is most prob clogged! Go underneath and tap them with a hammer. If you hear clanking / rattling etc.m on the inside its a sure sign thery are clogged. To get you on the road untill you can secure a new one, take off tye Y Pipe and using a long broom handle push all the crud out. Put your Y pipe back on and your done.
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  #23  
Old July 21st, 2015, 12:21 AM
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Could be ECU. Not likely though. Does the check engine light come on and then go off when you first start the truck? If not, yes you need an ECU. If it does, I doubt it is the ECU. Still possible though. I would start with disconnecting the MAF and see if that fixes it. You will get a check engine light, but it narrows it down. Next, replace the VSS (vehicle speed sensor). Cheap enough.

Could be cats, but they rattle before they fail completely in my experience.
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  #24  
Old July 21st, 2015, 03:21 AM
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mike hall
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MSB100860 80772a on the ECU (no ERR #) also has a 2 4 98 date code, which indicates to me that it has been previously replaced or either whoever he sent the durn thing to, shipped back a different unit. Took the numbers over the phone, so it's possible I didn't get it all taken down correctly. Heading to the shop today after work so that I can put my eyes on it. From what I've been able to find on the internet, the MSB100860 was replaced with MSB000120.


The mechanic started with the cats, said one was clogged and knocked it out, still had the problem. He also replaced the crank position sensor (the tit on the end was slightly bent). let's see, what else.... changed the coil pack, no improvement, put the old one back in.




I disconnected the MAF before I ever took it the shop, no improvement. I'll get a VSS ordered today.


thanks for all the help/suggestions!
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  #25  
Old July 21st, 2015, 04:13 AM
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Good luck. You will get it sorted eventually even though it may not seem that way. If the end of the CPS was bent, you could have a bad ring on the flywheel thing. Only seen that once though.

You could have a bent valve too. Did you check compression?
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  #26  
Old July 21st, 2015, 06:30 AM
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mike hall
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I'll check on the compression check. thing is, it purrs like a kitten at idle, or did. don't know if it's been started since the ecu came back.
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  #27  
Old July 21st, 2015, 07:11 AM
Departing90
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Unfortunately you have to go through the process of elimination and its a pain. I would leave the y pipe off to eliminate any possible cloggage for now. a bad fuel pressure regulator located on the fuel rail or a clogged fuel filter both have the same symptoms your describing if not working properly. Check the 2" long black rubber hose on the regulator for cracks.

Compression test takes a few minutes and reveals a lot. I dont agree with a bent valve but a wonky cylinder compression or rounded cam lobes can kind of have the same symptoms.

Take out all the spark plugs and lay them out on a table relevent to the positions they were in the engine and look for any anomalies. if not already installed use " champion copper heads". Makes a huge difference! dont forget to check the gaps.

Make 100% sure the spark plug wires are on the correct cylinders and then do it again!

------ Follow up post added July 21st, 2015 06:18 AM ------

There is an anomaly in some 4.0 ecu that also have kind of the same symptoms. Disconnect both oxygen sensors and rev the engine. If it revs fine replace one or both sensors. If it dosnt make a difference then that's eliminated.
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  #28  
Old July 21st, 2015, 08:43 AM
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Did this just start happening or did it build over time? Evil is right about disconnecting the MAF to see if the engine will then accel. This forces the ECU into limp mode. If it corrects the problem the MAF is dirty/bad or there is a massive vacuum leak. I'd also look at the TPS. A clogged cat will cause low power and usually presents itself with less and less power at highway speeds over time. I experienced the low power and higher operating temps on my DI (but the ragged fan clutch and clogged rad didn't help much either). The rattling at start up is a definite indicator. As noted, climb under while everything is cool and bang the cats with your palm or rubber mallet. If it rattles it needs to be replaced. I just replaced my Y-pipe using Davico 57092 from Rockauto ($338 + shipping) and it was a perfect fit. You'd use the Eastern 40469 ($383).
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  #29  
Old July 21st, 2015, 06:56 PM
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mike hall
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thanks again everyone. just left the shop. more frustrated than ever. mech doesn't have a clue about these trucks. new recommendation, "put in a chevy crate motor". the shop that he sent the ecu to, just had a bill that just said "no replacement parts available". I would have expected a little more detail. i'm bringing the truck home on Friday.


Mark G. -the problem started all at once, a couple of weeks after I replaced the o2 sensors, ran fine on the way to work, then lost power on the way home after about 5 miles of travel. I don't recall any rattling at start up.
I checked all the hoses for vacuum leaks prior to taking it to the shop even though I had recently replaced them. also checked the spark plug wires and plugs. plugs had a lot of carbon.


the folks on this site have really provided a lot of info on things for me to check, so i'm ready to get the truck back and get to work. willing to ship it to a Rover shop. the closest one that i'm aware of is "The Shop" in Norcross, Georgia. that's where the PO had it serviced any other recommendations appreciated.
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  #30  
Old July 21st, 2015, 07:23 PM
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Jose Urena
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will this loss of acceleration can also happened to a td5. Loss of accel but stays at idleling speed
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  #31  
Old July 21st, 2015, 10:01 PM
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Engine starts runs idles. So you can eliminate everything except fuel delivery. When you open the throttle you run out of gas. So where's the fuel starvation coming from? I would suspect the fuel pump first. It is certainly making pressure or else you wouldn't be able to start it. It may be having trouble picking up fuel. It could also be your in line filter or a problem in the line. Be sure it is clear. Doubt it's ignition related.
PS oxygen sensors do nothing until engine reaches operation temp.
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  #32  
Old July 21st, 2015, 10:10 PM
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mike hall
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thanks Bill, installed a new fuel pump and filter prior to taking it to the mechanic. also changed the stepper. i'm grasping.
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  #33  
Old July 21st, 2015, 10:39 PM
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If it idles your stepper is fine. Ditto fuel pump. Somewhere between tank and injectors there's a problem.
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1966 109 5 door wagon 300Tdi "spermaceti fueled"
1994 RRC LeWiB "ruining the air behind me"
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  #34  
Old July 22nd, 2015, 06:37 AM
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Alternately if the return is jacked it'll act the same as a clogged supply
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1966 109 5 door wagon 300Tdi "spermaceti fueled"
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  #35  
Old July 22nd, 2015, 07:20 AM
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Jeff B
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Quote:
Originally Posted by bamanuke View Post
the folks on this site have really provided a lot of info on things for me to check, so i'm ready to get the truck back and get to work. willing to ship it to a Rover shop. the closest one that i'm aware of is "The Shop" in Norcross, Georgia. that's where the PO had it serviced any other recommendations appreciated.
Luke, who owns The Shop is a good guy. I've wheeled with him a few times.
If you end up taking it back to him I'm sure he can get it straight.

.
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  #36  
Old July 22nd, 2015, 08:20 AM
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Quote:
Originally Posted by Tyler Wirken View Post
Make sure to check the Main intake hose coming from the Mass air flow sensor to the plenum. Mine looked fine until I checked the bottom side of the hose and it was totally rotted out and full of holes. It would run fine in the city but as soon as I hit highway speeds up around 3,000 RPM it would cut out. Just a thought.
3x. Your symptoms are as described by the PO of my truck. The MAF hose ended up having small slit in it that would only open under a large vacuum from the plenum. Static, you could not see the split. It was caused by the knuckle on the steering linkage. He tossed $1000s chasing everything. Remove the hose and inspect it again.
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  #37  
Old July 22nd, 2015, 11:55 AM
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not likely the ecu...

could be cats but that doesn't just happen

I would look at the MAF very closely.... it may not be sealing correctly or bad... a disco 1 will replace it..

please let us know the outcome.....
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  #38  
Old July 22nd, 2015, 12:45 PM
psykokid
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Since you've already changed out the crank position sensor you might want to check out the cam position sensor and associated wiring. If either the CKPS or the CMPS are on the fritz the ecu on the GEMS motors the ecu cant accurately fire the injectors in the correct sequence since the EFI in the GEMS motor trucks is a sequential EFI..

Quote:
Camshaft position sensor (CMP Sensor)
The camshaft position sensor is located in the engine
front cover. It produces one pulse every two
revolutions. The signal is used in two areas, injector
timing corrections for fully sequential fuelling and
active knock control.
If the camshaft sensor fails, default operation is to
continue normal ignition timing. The fuel injectors will
be actuated sequentially, timing the injection with
respect to top dead centre. Injection will either be
correct or one revolution out of synchronisation. The
fault is not easily detected by the driver. The fault is
indicated by illumination of the malfunction indicator
light (MIL) on North American specification vehicles.
Also - did you replace the entire fuel pump assembly or did you just replace the pump itself? If you just replaced the pump and reused the old housing it's possible that the line coming out of the fuel pump isnt sealing correctly and at idle is providing enough fuel pressure, but once the rpms pick up enough fuel is leaking out and causing a drop in pressure.
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  #39  
Old July 22nd, 2015, 05:45 PM
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mike hall
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replaced the entire fuel pump assembly and the rubber lines from the pump to the hard lines. they were in foul shape.


the mechanic is telling me that a couple of the coils in the coil pack are not getting a signal to fire, according to him, that signal comes from the from the ECU. He also said that the ECU repair shop confirmed that the "processor" in the ECU was no good but the fuel side was fine. outta my league


I've spent untold hours searching for a replacement ECU and it looks like I may finally have a lead. just hate to drop $1k on it if it's not the issue. thanks again all!
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  #40  
Old July 22nd, 2015, 06:42 PM
psykokid
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Quote:
Originally Posted by bamanuke View Post
replaced the entire fuel pump assembly and the rubber lines from the pump to the hard lines. they were in foul shape.


the mechanic is telling me that a couple of the coils in the coil pack are not getting a signal to fire, according to him, that signal comes from the from the ECU. He also said that the ECU repair shop confirmed that the "processor" in the ECU was no good but the fuel side was fine. outta my league


I've spent untold hours searching for a replacement ECU and it looks like I may finally have a lead. just hate to drop $1k on it if it's not the issue. thanks again all!
Ouch. that's steep for an ECU. I forgot to check the ones that I have, I'll look at them when I get home and let you know if one of them matches yours. I can ship it out to you and you can give it a shot, if it works out and the ECU is the culprit then great. If its not the ECU and the issue persists, no harm no foul, just ship it back to me.

IIRC I think i have an ecu for both GEMS with AEL and non AEL. Just depends on which one you need. I have a friend at a dealership that can probably put the ECU into learn mode, i'll have to check and see.
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