MG-Rover.org Forums banner

1 - 20 of 20 Posts

·
Registered
mgf
Joined
·
344 Posts
Discussion Starter #1
Ok basic script.
when the car is cold it ticks over perfectly at about 1100 1200 revs
once it is warm it ticks over about 800
the problem is that every 12 or so seconds the the revs drop to about 100 occasionaly it does this twice in a second and stalls the engine. t is as if the car isent firing.

as soon as the revs go up the car runs fine.

the car just had the cilinder head gasket replaced and an open cone filter fitted. The open cone has no cold air feed.

Any one got any ideas at all??

thanks
 

·
Registered
mgf
Joined
·
344 Posts
Discussion Starter #4
When your driving the engine seems fine the only time it skips a beat is at low revs and under stress, the car revs freely and pulls up to 6000 revs (I havent taken it higher yet but I'm sure it would go to the limmit).

I read in the forum that the HT leads could cause this issue but the leads and plugs are new and have been routed using the guides.

I'm totaly at a loss.

The vvc mechanism should only come on at 4000 rev any way to test if its constantly on?

Thoughts?
 

·
Registered
Joined
·
417 Posts
Trun the key in 2 position. Push the gas pedal to the max 5 times repeatidly. Wait for approx 30 seconds. Turn of the ignition key. Then it should be ok.

All best SImon
 

·
Registered
Joined
·
17,819 Posts
simon.guna said:
Trun the key in 2 position. Push the gas pedal to the max 5 times repeatidly. Wait for approx 30 seconds. Turn of the ignition key. Then it should be ok.

All best SImon

Ahhh so not the VVC system then.

You have just described the IACV reset procedure.
 

·
Registered
Joined
·
15,938 Posts
simon.guna said:
Trun the key in 2 position. Push the gas pedal to the max 5 times repeatidly. Wait for approx 30 seconds. Turn of the ignition key. Then it should be ok.

All best SImon
that will reset the stepper motor but this doesn't appear to be a stepper motor issue a its idles fine just blips.

when were the plugs/leads/dissy cap and rotor arm last changed?

andy
 

·
Registered
Joined
·
17,819 Posts
AndBurG said:
that will reset the stepper motor but this doesn't appear to be a stepper motor issue a its idles fine just blips.

when were the plugs/leads/dissy cap and rotor arm last changed?

andy

OP has stated that the leads and plugs are new.

No dizzy cap or rotor arm as the car is a VVC.

possible crank sensor?
 

·
Registered
Joined
·
417 Posts
You said, when its cold runs fine, only when is warm revs drop. This could be CTS fault. The CTS gives the CPU wrong info about the temp. This is my opinion.
 

·
Registered
mgf
Joined
·
344 Posts
Discussion Starter #11
I will test the car again tommorow AM (when it is at its coldest) I'll let the car idle and time it untill it skips a beat.
 

·
Registered
mgf
Joined
·
344 Posts
Discussion Starter #12
OK,
dicovered why it's ok when cold......its because the revs sit at about 1200-1300 when its cold and at idle. when hot the revs are down to 800 and the car skips below 1000 revs. So back to the drawing board.

anybody?
 

·
Registered
mgf
Joined
·
344 Posts
Discussion Starter #13
Well I took it to a dealer to get it tested with computer and they recon that its the timing, If it was the timeing wouldent the car idle rough all the time and not just every 10-12 sec lose a beat?
 

·
Premium Member
Joined
·
31,560 Posts
cjmillsnun said:
OP has stated that the leads and plugs are new.

No dizzy cap or rotor arm as the car is a VVC.

possible crank sensor?
Erm, I think you'll find the VVCs have indeed got a dizzy cap & rotor arm, its only the newer EU3 engines that have wasted spark
 

·
Registered
Joined
·
782 Posts
How recently has the head gasket been replaced, if fairly recent then the ECU needs to re-learn certain values by going through various drive cycles. Once re-learnt it may settle down. Other option is to have reset by Testbook or other suitable diagnostic tool.

Regards
DaveH
 

·
Registered
rover_25
Joined
·
184 Posts
SteveChilds said:
Erm, I think you'll find the VVCs have indeed got a dizzy cap & rotor arm, its only the newer EU3 engines that have wasted spark
I had a P reg 200 vi which was wasted spark, and I'm pretty sure that predates EU3.

Mark S
 

·
Registered
mgf
Joined
·
344 Posts
Discussion Starter #17
the gasget was done about 3 weeks ago ( 500 - 600 ) miles

Had a chat with the boy that had it on the machine
because it had the head gasket replaces the first thing they would do is check the vvc timing (£240 + vat)

Faults comming back were
Internal ECM voltage too high
Ambient air temp sensor
Coolent sensor
oil sensor

None of these could be reset

The other fault was "high resistance drivers airbag ECU internal fault. capacitor

£152.96

So £80 lighter and no further forwards
does any of the above make sence to anybody?
 

·
Registered
mgf
Joined
·
344 Posts
Discussion Starter #19
OK we are further forward (sort of)
since the last post the inletmanifold gasket has been changed and a "borrowed" throttle body put on the car.
It has made a very considerable difference. The car no longer stalls and the frequency between the engine dipping has reduced from every 10secs to about a min --> 2 mins.
The only other thing that has cropped up was twice when I stopped at lights the revs stayed at 1500 as if my foot was still on the gas. I'm thinking a bit of use will cure that (somthing a bit sticky).

anyone got any ideas on the engine dip?
 

·
Registered
Joined
·
1,114 Posts
SteveChilds said:
Erm, I think you'll find the VVCs have indeed got a dizzy cap & rotor arm, its only the newer EU3 engines that have wasted spark
My old VI had Coil pack that was S Reg, and my BRM V Reg 99
 
1 - 20 of 20 Posts
Top