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· Adam G
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16 Posts
Discussion Starter · #1 ·
Hey guys:

Been a while since I've posted on LRO, been over on RangeRovers.net. Hoping the community here can help with some insight into my RRC.

Kind of can't figure this one out. Over the past year I had been running a 4.2 fuel map chip on my RRC with a 4.6 block upgrade. Reason was I had broken a pin on my Tornado chip pulling it from a fried ECU. I had also been running the cleaned, but original Lucas injectors. Things were ok fuel trims weren't really balanced, but within about 20%. I had assumed this was on account of the 4.2 map in a 4.6 block. I have wanted to get that tightened up on account of my mpg being around 9.

After about 4 months, I got my Tornado chip back from Mark Adams. In those months, I had also aquired 8x upgraded Bosch injectors (4 hole), the direct replacement everyone does (yellow). They came from Motorman, on eBay, well respected.

The new injectors went in easily. I decided to pull the 4.2 chip and go back to the 4.6 Tornado chip while I was at it.

A few tanks later, I was checking my mpg. No change since my abysmal 9 mpg.

I thought that was really disappointing news after the upgraded injectors (which, I noticed ran MUCH quieter and smoother).

So I checked fuel trims to see if the fuel map was working better with the new injectors. I was surprised to find that the long term fuel trims were -83% and -100%.

Uhg. So I ran it for another tank, and it ended up moving around a bit, and landed somewhere around -38% and -70% or something. It sat there for a tank. It went back to -90s... so I reset the ECU and ran for another tank or two. Again, back to the -100 LTFT on one bank, and -70 something on the other.

Some more info, I have worked on the ignition system, and fuel delivery for the past year or so here goes:
-MAF reads 1.8V, (haven't checked the resistance curve thought), smoke tested,
-No vacuum leaks except a very small (normal) one at the throttle spindle gasket.
-TPS checks (voltage and map looks good),
-IACV is ok (replaced, just for fun),
-Fuel Pressure Regulator,
-Vacuum advance,
-rotor arm is red, cap is good, wires are good, NKG plugs as preferred, etc etc.
-Compression checked, and even, somewhere around 135 warm with starter IIRC.
-Sensors all working, coolant temp, fuel temp etc. Rover gauge also shows they are all reading just right.
-O2's are new, I've watched them cycle on my oscilloscope. Clean and normal signals.
-Distributor has been checked, gap is set perfectly.
-Pulse off amplifier and coil look just right. New coil was installed, new amp installed.

Fuel, compression, spark. All good.

Timing I've had from 12 to 5 BTDC. Really doesn't seem to make any difference. In fact, when I bought the truck it was 12 ATDC and it ran almost the same, and got the same gas mileage! Checked that the mechanical advances are working. Seems so when I rev, to jump to around 20 or 30 degrees accelerating.

WHAT am I missing? Is there something that the previous owner could have done that simply makes this engine inefficient? Is there anything else that I might be missing? Note, he also installed a crower cam with the block upgrade.

The only other thing I'm left to consider is that:

1: The injectors are not really the right flow rate (Makes no sense because everyone else has used them, and I've checked each one opens/closes)
2: This isn't actually a 4.6 block. Tornado map just isn't right.
3: I need a new distributor : Maybe the timing curves are just not working, so the timing is just not efficient? Or the spark

I feel like, maybe this is just a lost cause, and just needs a ground up rebuild. My expectation would be that this truck would be super straightforward to work on, which it is. All the variables are accounted for, but they just don't add up. Can't tune this thing at all.

Thanks for any ideas guys.
 

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50 Posts
Hey guys:

Been a while since I've posted on LRO, been over on RangeRovers.net. Hoping the community here can help with some insight into my RRC.

Kind of can't figure this one out. Over the past year I had been running a 4.2 fuel map chip on my RRC with a 4.6 block upgrade. Reason was I had broken a pin on my Tornado chip pulling it from a fried ECU. I had also been running the cleaned, but original Lucas injectors. Things were ok fuel trims weren't really balanced, but within about 20%. I had assumed this was on account of the 4.2 map in a 4.6 block. I have wanted to get that tightened up on account of my mpg being around 9.

After about 4 months, I got my Tornado chip back from Mark Adams. In those months, I had also aquired 8x upgraded Bosch injectors (4 hole), the direct replacement everyone does (yellow). They came from Motorman, on eBay, well respected.

The new injectors went in easily. I decided to pull the 4.2 chip and go back to the 4.6 Tornado chip while I was at it.

A few tanks later, I was checking my mpg. No change since my abysmal 9 mpg.

I thought that was really disappointing news after the upgraded injectors (which, I noticed ran MUCH quieter and smoother).

So I checked fuel trims to see if the fuel map was working better with the new injectors. I was surprised to find that the long term fuel trims were -83% and -100%.

Uhg. So I ran it for another tank, and it ended up moving around a bit, and landed somewhere around -38% and -70% or something. It sat there for a tank. It went back to -90s... so I reset the ECU and ran for another tank or two. Again, back to the -100 LTFT on one bank, and -70 something on the other.

Some more info, I have worked on the ignition system, and fuel delivery for the past year or so here goes:
-MAF reads 1.8V, (haven't checked the resistance curve thought), smoke tested,
-No vacuum leaks except a very small (normal) one at the throttle spindle gasket.
-TPS checks (voltage and map looks good),
-IACV is ok (replaced, just for fun),
-Fuel Pressure Regulator,
-Vacuum advance,
-rotor arm is red, cap is good, wires are good, NKG plugs as preferred, etc etc.
-Compression checked, and even, somewhere around 135 warm with starter IIRC.
-Sensors all working, coolant temp, fuel temp etc. Rover gauge also shows they are all reading just right.
-O2's are new, I've watched them cycle on my oscilloscope. Clean and normal signals.
-Distributor has been checked, gap is set perfectly.
-Pulse off amplifier and coil look just right. New coil was installed, new amp installed.

Fuel, compression, spark. All good.

Timing I've had from 12 to 5 BTDC. Really doesn't seem to make any difference. In fact, when I bought the truck it was 12 ATDC and it ran almost the same, and got the same gas mileage! Checked that the mechanical advances are working. Seems so when I rev, to jump to around 20 or 30 degrees accelerating.

WHAT am I missing? Is there something that the previous owner could have done that simply makes this engine inefficient? Is there anything else that I might be missing? Note, he also installed a crower cam with the block upgrade.

The only other thing I'm left to consider is that:

1: The injectors are not really the right flow rate (Makes no sense because everyone else has used them, and I've checked each one opens/closes)
2: This isn't actually a 4.6 block. Tornado map just isn't right.
3: I need a new distributor : Maybe the timing curves are just not working, so the timing is just not efficient? Or the spark

I feel like, maybe this is just a lost cause, and just needs a ground up rebuild. My expectation would be that this truck would be super straightforward to work on, which it is. All the variables are accounted for, but they just don't add up. Can't tune this thing at all.

Thanks for any ideas guys.
First, was it always 9mpg? why does 135 compression seem low to me. I have a 4.2 with a tornado chip. I am going to test it this week with the old chip back in. My rebuild has 3k miles on it. it runs perfectly. It has a piper torque max cam.. not sure how it compares to your crower..My rover gets the same mileage at 8 to 15 btdc and runs almost exactly the same. That always bugs me..lol ..Do you have a 4.6 intake and MAf sensor? They have a voltage setting and a rewire if you ad the 4.6 MAF to a lesser engine-ecu.. thats on the rpi website someplace.. what transfer case is in this, viscous or lt230? if Lt230 what gear ratio? what is your rpm at 70 mph? I am told it should be 2650. What size tires are on this range rover? I have noticed that my rig gets less mileage since the chip install. My parts came from RPI, you could email them and see if they have an answer for you? That Ian over there is extremely bright about these rovers..
 

· Adam G
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16 Posts
Discussion Starter · #3 ·
It has always gotten about 9mpg, as it came to me. I think I may have gotten as much as 11 on highway.

4.6 sensor was recommended by Ian, actually. But I've run the 3AM and 5AM and it looks ok in rovergauge? What would be the difference with the 4.6? I'm also asking Ian. I'd do this swap if I understood it would fix the overfueling.

Transfer case is the Borg viscous. I actually replaced it with a rebuild not long ago.

Tires are not oversized. They are about 5% larger than the originals, with treads. Nothing crazy, 1.5" lift.

135 was the wrong number. It was 153, I just checked my notes. All 8.
 

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It has always gotten about 9mpg, as it came to me. I think I may have gotten as much as 11 on highway.

4.6 sensor was recommended by Ian, actually. But I've run the 3AM and 5AM and it looks ok in rovergauge? What would be the difference with the 4.6? I'm also asking Ian. I'd do this swap if I understood it would fix the overfueling.

Transfer case is the Borg viscous. I actually replaced it with a rebuild not long ago.

Tires are not oversized. They are about 5% larger than the originals, with treads. Nothing crazy, 1.5" lift.

135 was the wrong number. It was 153, I just checked my notes. All 8.
Okay let me see, for my 4.2, the Tornado chip was offered as a chip that would overcome the lean condition that supposedly led to cracking of blocks. so, if the answer was to feed it more fuel instead of less.,then the tornado chip is at least possibly and partially responsible for my lack of fuel mileage economy.. Now I am getting closer to arriving at the answer in here somewhere I think.

If by using the Tornado chip, I add fuel "in certain situations" and I use a camshaft " torque max" that moves the power down the RPM scale then I am making it less efficient than it was when it came from the factory. Then I change from the tin head gasket it came with to the composite but thicker gasket I lose compression, so I have lost power and efficiency and added to it with all the changes I added to improve it. I have a rebuild currently underway, I have a completely stock setup so far, waiting for assembly. pistons are factory size, I have a new stock cam for a 4.2, and I could put it together with tin gaskets. and try it. with the factory chip, I think my mileage would improve.
I think the engineers at Land Rover had this all figured out and that all this fiddling I am doing is a waste of time, to gain more power, I gave up my efficiency. after all the years Land Rover engineers spent with this engine type they probably got the most they could out of it. When I bought this rover 12 years ago, it actually achieved 16 mpg once on the highway, before the head gaskets blew, then the cracks behind the liner. I had it welded and re-sleaved with +.020 pistons and it ran for 10 years getting around 12mpg in town and 14-15 mpg on the highway. then my crankshaft balancer came lose broke and sent chunks into the timing chain ruined it. I got another block and started over. now everything is "improved" and I get 10 mpg. all that's different is the Tornado chip, the cam.

sorry I went astray..lol I have the same 4 spray injectors as you, these worked fine engine #1 rebuild, maybe they do not flow enough for the chip changes? in a nut shell the only difference in my builds is the chip and cam.. no engine ran smoother than the current build, it has more power down low but runs out of pull and power at about 4k, so from zero to sixty it is improved but 40 to 80 is lackluster to wimpy. Thank you Torque Max Cam!,,. in town the mileage is 9-10 I haven't driven it on the highway on a long trip so I do not know the mileage after 2 tanks at 70 mph.. I think I want to do this next engine with tin gaskets and ARP studs and see if increasing the compression will give me back some power and I will use the stock cam, stock chip, and see what happens. I like Ian at RPI but I think the focus there is on low end power and torque, given that most of their videos are manual transmissions showing off being in 5th gear at 35 miles per hour. Not sure they get the 80 miles per hour on the highways of California, with ethanol? I will repost what happens when I go back to stock. I will even put my stock dia. tires back on and see what results I get. TWS motors has some injector offerings, and some other interesting items, their 4.6 might be the ticket. I just ordered a set of their high performance 14 bolt heads for the engine currently in the rover. so I will have 2 engines one stock, and one altered and running chip, ignition etc. I feel I am going to find all the performance upgrades were really very minor improvements that resulted in less efficiency. .Then I am going to scream..lol
 

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I have a similar 4.6 conversion on my 95 lwb, I am using a gems 4.6 chip and not a tornado , factory injectors, gems mass airflow sensor factory 4.2 cam. I have converted to EDIS megajolt from trigger wheels. ditched my dizzy
huge difference, I get about 350 miles to the tank on highway driving at 70mph and roughtly 250 miles city driving with A/C on. no start issues plenty of power (full throttle I can chirp my wheels at a light) and you can adjust and modify your timing curve with a laptop. hands down best mod ever.
my last run I drove from richmond va to springfield va on a bit less than an 1/4 tank with a/c on. on comparison my 2kp38 also a 4.6 with recent overhaul (about 1500 miles since start) uses about 3/8 of a tank on same run.
 

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Carlosz - Do you have any pics of the EDIS megajolt install? Please provide more detail on it. Your gas mileage is outstanding.

I’ve got a 4.6L, DUI distributor, mark adams chip and have been pleased with the set up, but I’m not chirping tires…


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pictures of the whole install process, no I do not have. of the finished product I am sure I can attach. being a 95, my coil had resided next to radiator thus seemed to be the obvious choice to install the edis 8. all power ground and signal wiring was kept short and tied to factory as possible.
the edis will run at nominal 10 degrees with out a controller, the controller houses all timing table programming, that made residence on the same bracket as the alarm module and the required wiring was run inside the same harness sheath running to the 14 cux ecu. no extra wiring or harness all over, looks factory.
the trigger wheel is of course mounted behind the harmonic balancer and the crank sensor on the timing cover on a bracket supplied in the kit.
you do get basic general instructions, such as run power from fuse box or a fused circuit or run fuse line, I modified my wiring by using power from ecu wire and ignition circuit, my logic if power to 14cux fails I can trace all circuits in one shot, if ignition circuit fails I can do the same and not try to figure out any unlabeled extra wiring.
you do get a basic rover v8 ignition timing map, using the road as my dyno, I tweaked the numbers to a happy place.
the kit is ford based, it comes with ford coils and wiring. I wanted to keep all land rover to ease in locating replacement parts and wanted a hotter spark, so I went with Davis Unified Ignition SOS coils and wiring specked for land rover, I have the custom tailored wire set and part number and bosh +4 plugs.
I am detailed and think out of the box, since harmonic balancer would be out I procured and replaced the front main seal at the same time, cleaned and dressed the balancer and any oil residues, soldered all connections etc.
the install takes about a day, all wires fall in place. BTW all those wires seem overwhelming initially LOL. oh and one last thing/thought. the distributor gear keeps the cam from walking thus you need a distributor, some people have kept the whole unused dizzy in place, I procured a junk rusted unit and modified it to be just a shaft to plug the whole and hold the cam in place (similar to what gm did with electronic ignition 350's prior to LS's). I cut the top, welded a washer and all I have is a turning shaft which is covered by coils on top. will post picts asap
 

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thanks, trial and error. tried going the dizzy upgrade but I would have been back to square 1, many rotating assemblies, 100 yr old technology and lots of possible failure points all over again, coil, cap, module rotor. counter weights, timing lights moisture, vacuum advance etc.
a dui or other dizzy anywhere from 700 to 1k bucks, EDIS about $800 including coil and wire upgrade and newer technology.
I thought of even newer coil on plug technology, but after market technology for older some what obscure engines such as rover is not there yet.
I have never taken a video of it performing on the highway, I may be tempted to do one and post just for kicks and giggles, it used to be it would rev and climb speed slow but steady, now I rev and both gauges climb simultaneously.
 

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A video of the engine running and one driving would be awesome.
I’d love to hear it and see it operational.

I’m a fan of the DUI dizzy. It has worked flawlessly on my rig for several years without issue. But you are getting significantly better performance from your setup.

BTW, we are a bit afield from the original post. You may want to start a new thread.


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· Adam G
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16 Posts
Discussion Starter · #12 ·
Wanted to update here. Looks like the thread has gone wild! I tried a few things, but right now I've adjusted my MAF CO trim to 1.6v. Tornado recommends 1.8, but as I've come to understand, these Lucas MAF's @ 30 years old, can be off. I trusted that the fuel map from Tornado was good, so probably with all other things in working order and within range, I could lean the mix out by bringing the air meter flow variable down a smidge. .2 volts and the LTFT's are more centered. It has sort of wandered from week to week I've noticed. Highway driving it seems to try to lean the mix, and in town it centers more. Not sure what's going on, but at least the trims are within range now!
 
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