It's just sort of stops at 3000rpm. Foot flat to the floor and the revs just stay at 3000 no hesitation, no missing just stops.

Will go higher in neutral but will not rev freely past 3000 even then and will only get to 4000. Won't hit the limiter.

When's it's cold and I give it some beans it will hit the limiter but as soon as its hot it will start revving to say 3700 then if I try again 3000 every time after that. Seems to be down on power when it starts to do it too, becomes harder to actually get it to 3000 but never missfires.

Also started to like stalling when selecting reverse or drive from neutral or park. The bit of extra load seems to kill it.

All that makes me think it's spark related, because it's like a 3000 rpm rev limiter.

Chaned or swapped everything. Got a igniter cool and new dizzy pick up coming tomorrow so I'll try yet again!!!

Thanks for all the help.
 
This is not the first time I have heard of this after a cam change .I have
been meaning to change my cam for a piper or suchlike but am realy
worried I will end up in the same boat,I think at sometime you may well
have to change the cam for a standard one if only to rule it out.
Good luck hope its something simple . This is just a thought have you
removed the rotor arm ?. The shaft in the distributor has a habit
of pulling up and leaving the springs rattling around and a load of play in
the arm.
 
boycie said:
This is not the first time I have heard of this after a cam change .I have
been meaning to change my cam for a piper or suchlike but am realy
worried I will end up in the same boat,I think at sometime you may well
have to change the cam for a standard one if only to rule it out.
Good luck hope its something simple . This is just a thought have you
removed the rotor arm ?. The shaft in the distributor has a habit
of pulling up and leaving the springs rattling around and a load of play in
the arm.
Click to expand...

Be interested to hear what other stories of cam changes you've heard?

When it's cold it pulls noticebly stronger after the cam change but that only lasts until it gets upto temp!!

Did check the rotor arm and dizzy shaft. I take it you mean it pulls up the shaft and pings off the mechanical advance springs beneath the baseplate. My arm when slightly rotated will spring back to posistion so that all seems ok.

I'm sure i've read somewhere that the Lucas 14cux system doesn't like cams with a lobe seperation of 112degrees or more as it messes with the air flow signal or pressure in the plenum!!! Mt cam is 112 degrees and i did once get a fault code reading of air intake leak/stepper motor fault/ other mechanical problem. Now seeing as the cam is the only thing i've changed since this problem has and i've even tried new lifters logic says that it has to be the cam causing the issue!!!

I've got a Mark Adams fuel chip in my draw from another v8. I'll speak to him and get it programmed for my car and see if it cures it!

I feel this issue will be forever ongoing and cause me to consider...diesel!!!!!
 
I put these up before on a previous that but that thread vanished so...

[ame=http://www.youtube.com/watch?v=1IEn41CTulU]DISCOVERY V8 CAN REV.MOV - YouTube[/ame]

When engine is warm but not hot, been running for about 5 min. Engine picks up fine, revvs freely, pushed hard will ding the limiter...all is good in V8 land!
 
Now when at full running temp after about 25 min driving. Doesn't pull aswell through rev range, my foot is flat the whole time ( when it's revving up anyway ) but the engine just seems to stop running. It goes quiet and revs slowly drop. Revs stay up but it just seems like it's coasting!!

[ame=http://www.youtube.com/watch?v=B9wXSORUhPE&feature=related]DISCOVERY V8 NOT REVVING PAST 3500RPM.MOV - YouTube[/ame]
 
It looks like the distributor is ok. I have been looking on the forums for some time regarding cams trying to make my mind up which to fit, seen a few reports of problems simular to yours after fitting performance cams one in particular was almost identical, it turned out he had been given a cam suited to solid lifters ,I have no idea of the difference but once replaced with a standard cam it was back to normal . I am not sure which
forum it was on sorry.
 
Interesting. I did read similiar on this forum. The place I purchased the cam say its a straight swap, no stiffer valve springs no need to machine anything. They also recommend roads lifters which I've fitted. As I said before I'm going to speak with mark Adams regarding a re chip. He must have seen a problem like this before!!
 
that is ****ing weird!

the change in engine note, instantly, its like youre foot comes off the throttle...

that, mate, is weird.
 
all the wiring is back on after the cam change ?temp sensor's , engine and water ?
 
Ive got my fingers crossed for you. Were did you get the cam from and
what make and model is it ?. If it's not the cam may get one if you rate it.
 
Mr Noisy said:
that is ****ing weird!

the change in engine note, instantly, its like youre foot comes off the throttle...

that, mate, is weird.
Click to expand...

Really weird I know!!! sounds and acts exactly like I've lifted off the power, but I haven't. I'd have thought if it was fuel cutting and it was still sparking it would pop and bang but if the spark stopped it'd just stop...like it does in the vid
 
joe1972 said:
Have you tried a different ECU?
If not, worth doing...that is definately not right!
Click to expand...

Yep, tried another ecu. No different.

The old cam followers looked ok and none of the cam lobes were shot, engines only done 64k just fancied abit more poke and now I wish I'd never bothered!!!
 
boycie said:
Ive got my fingers crossed for you. Were did you get the cam from and
what make and model is it ?. If it's not the cam may get one if you rate it.
Click to expand...

Crower 50229 from v8 tuner. I do rate the cam, when the engines cold at least. Suits 4x4s well not a high revving thing, works well from low down.
 
The situation is like something is maxing out.

You're gonna have to do more tests, good thing is that it's a simple system to diagnose.

You need to drive along the road and get a mate to pull the fuel pump fuse at 3k, see if that feels similar.

Next, rig up a pair of test lamps on the dash that are wired into the ECU plug injector circuits, get them so that they will flash every time the injector banks are pulsed, then go for a drive and see what happens when you lose power - does it still inject?

Is it fuel pressure regulation?

Take a feed at the ECU to your multimeter, monitor the MAF circuits to check the airflow and CO trim value, what happens when the car loses power? Does something change?

You are going to have to get a mate in the car to help and go through every single input and output on that ECU until you find something odd.

If not, then it's time to hook up some spark plug lights, take the bonnet off and go for a drive in the dark with your mate hanging out the sunroof, too see if it's still sparking as it should be on all 8 when it loses power.

Once youve tested everything it can't be anything else :)
 
That was going to be my next step dont have any spark plug tester so I was just going to clip the timing light to each lead and run it up to speed. Going to connect a led to the injector pulse wire and check that it doesn't do anything odd. Maf will be easy to test with a multi meter.

Tried to normal and one adjustable fuel regulator and check the pressure. Also had the flow rate checked.

Going to wire two switches to kill the power to the coil and injectors when I'm driving. Won't kill fuel pump as I figure it will still run on the fuel in the rail for a bit and not stop instantly.
 
You must log in or register to reply here.

Similar threads

styleruk
2.25 petrol rough idle
2 3
Replies
44
Views
2K
styleruk
styleruk
MAF Diver
Disco 2 Rough idle in a V8 D2a — tried MAF, O2, sparks, leads
2
Replies
35
Views
3K
marjon
marjon
J
ZENITH CD175 TEMPERATURE COMPENSATORS HELPFUL INFO
Replies
8
Views
2K
hef19898
hef19898
Ashs1
D2 v8
Replies
11
Views
1K
sierrafery
sierrafery
Becks Bear
3.9efi started to back fire after engine service
Replies
18
Views
2K
Ratae
R