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Omega Help Area => Omega General Help => Topic started by: mijfife on 04 October 2006, 19:34:16

Title: Uneven Idle - lpg related??
Post by: mijfife on 04 October 2006, 19:34:16
The GLS is running fine, took it for a quick test drive tonight just to check the auto box etc. The only issue I'm having is with an uneven idle speed. It is fluctuating between 500 rpm and 900rpm ish once it is warmed up. Started from cold, the idle is steady but much higher for a spell before it drops and starts fluctuating. I switched over to lpg and the idle increases to 2000rpm but is steady. I suspect that the disconnected & broken LPG Lambda is causing this when on gas. Is the idle control valve my most likely suspect? I take it, that's the shiny cylindrical thing on the inlet manifold?  ;) I've got a spare so will try it tomorrow anyway, just wondered if there was any other likely culprit.
Incidently, the engine management light has remained lit since I replaced the engine. As the battery was disconnected for several months, will this be a new problem or still lit from the knackered engine issues?
Many thanks, Jim
Title: Re: Uneven Idle - lpg related??
Post by: Craig_R on 04 October 2006, 20:53:11
Hi There

I had the same problem with my LPG High Revs

Cleaned all the breathers, The ICV, and the Throttle housing including the butterfly Valve with lots and lots of Carb cleaner and never had the high revs again. :)

Hope this helps

Craig
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 05 October 2006, 09:45:47
Thanks Craig,
                    I'll give everything a good clean today and see what happens

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: Eliteman Steve on 05 October 2006, 10:09:25
Hi , Might be an idea to try the paperclip test , see what codes are stored , if a problem is solved the management light should go out , though the ecu will store the code for about thirty 'clean' starts if everything is running as it should there should be no light , this suggests there is a fault somewhere and it may be related to the uneven idle . [smiley=thumbsup.gif]
Title: Re: Uneven Idle - lpg related??
Post by: Markie on 05 October 2006, 10:24:26
Dont know anything about lpg - but the revs are fluctuating quite a bit on traditional fuel arent they - clean everything, then clean it again ( carb cleaner perhaps)

Also those vacume pipes - did you ever change em - worth a shot .... :)
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 05 October 2006, 11:37:20
Thanks for the advice so far guys. I cleaned the ICV and the throttle housing with carb cleaner this morning. On start up from cold, the car idles steady at 1000rpm. On warming up, the idle drops to an uneven 600 - 800 rpm, fluctuating as if you are blipping the throttle. I changed the ICV for a spare from the other engine but it's still the same.
Vacuum pipes all look in good condition and I'm now pretty certain that they are in the right place. Breathers are all clear too. I'm about to change the potentiometer to see if that helps. My only other thought at the moment is with the camshaft sensor. the one that came with the replacement engine had a different plug from my wiring harness so I fitted my original one. Could it be anything to do with that??  
Cheers Jim

p.s. I meant to add, my car is a facelift so I can't do the paperclip test can I?
Title: Re: Uneven Idle - lpg related??
Post by: nixoro on 05 October 2006, 11:48:27
Quote
Thanks for the advice so far guys. I cleaned the ICV and the throttle housing with carb cleaner this morning. On start up from cold, the car idles steady at 1000rpm. On warming up, the idle drops to an uneven 600 - 800 rpm, fluctuating as if you are blipping the throttle. I changed the ICV for a spare from the other engine but it's still the same.
Vacuum pipes all look in good condition and I'm now pretty certain that they are in the right place. Breathers are all clear too. I'm about to change the potentiometer to see if that helps. My only other thought at the moment is with the camshaft sensor. the one that came with the replacement engine had a different plug from my wiring harness so I fitted my original one. Could it be anything to do with that??  
Cheers Jim

p.s. I meant to add, my car is a facelift so I can't do the paperclip test can I?

Did you clean the throttle body butterfly (disc) only I had this cleaned fully inc the ICV and made sure the small breather was clear and since then its been fine. Could be a sticking throttle body butterfly (disc)

Did you leave the ICV to soak for a little while as this can help wonders.

Unfortunately it a sod the facelift cant be tested using the paper clip method.

With regards the Camshaft sensor since you've fitted it is there any signs of the EML coming on. If not chances are it might be fine.
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 05 October 2006, 12:06:20
Engine management light been on since I replaced the engine. I'm not sure if this is related to a new fault or still there from the previously knackered engine.

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: Markie on 05 October 2006, 12:16:26
Decent run and how good is the battery ?

Never thought it but my very very slightly deviating revs ( i mean by about 100) seems to have gone since i took my dodgy battery out and replaced it.....
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 05 October 2006, 12:51:22
Hi Markiec,
               battery seems fine, as do all the earths. potentiometer changed and still no difference. I can't take it for a good blast as it isn't mot'd or taxed yet  :(
               I tried increasing revs to 3000rpm for about a minute and then letting it idle again. If anything it made it worse as it was almost cutting out. I also wired in another lambda for the lpg and just had it hanging loose in the engine bay. When I switched to lpg, the idle was must steadier at just under 1000rpm so I don't think it's related to the lpg system at all. It only seems to be acting up when running on petrol. Incidently, what should the idle speed be on a 2ltr auto?
               I've heard that some engines don't run to well on petrol after using lpg, could this be the problem? The engine was from an LPG car as well.
               When I take it for the mot, does  can the emmissions be tested on the lpg setting or does it have to be on petrol?

Cheers Jim
            
Title: Re: Uneven Idle - lpg related??
Post by: Markie on 05 October 2006, 12:56:34
Hmmmmm really dont have any knowledge of LPG at all - tbh not a fan.

Dont think your issues are lpg related as for is it related due to previously using , who knows.....

there`s a few lpg experts on here hopefully they should be able to solve that one.

Revs, mines sits at about 500rpm on steady idle, maybe a tad higher from memory. Not sure off the 4 pots rev on idle.....sorry not much use but i do think you have covered most of the normal reasons for the lumpy idle.

Know anyone with diagnostics locally to run a post facelift "paperclip?"
Title: Re: Uneven Idle - lpg related??
Post by: nixoro on 05 October 2006, 12:57:24
Quote
Hi Markiec,
               battery seems fine, as do all the earths. potentiometer changed and still no difference. I can't take it for a good blast as it isn't mot'd or taxed yet  :(
               I tried increasing revs to 3000rpm for about a minute and then letting it idle again. If anything it made it worse as it was almost cutting out. I also wired in another lambda for the lpg and just had it hanging loose in the engine bay. When I switched to lpg, the idle was must steadier at just under 1000rpm so I don't think it's related to the lpg system at all. It only seems to be acting up when running on petrol. Incidently, what should the idle speed be on a 2ltr auto?
               I've heard that some engines don't run to well on petrol after using lpg, could this be the problem? The engine was from an LPG car as well.
               When I take it for the mot, does  can the emmissions be tested on the lpg setting or does it have to be on petrol?

Cheers Jim
            

Not sure if manual/auto idle rev should be the same but my 2.0 manual usually sits just under 1k revs at idle.

HTH :)
Title: Re: Uneven Idle - lpg related??
Post by: Markie on 05 October 2006, 12:58:21
....only other thing is to let it run for a wee while - i am assuming its not runa while and the engine may have stood, maybe just needs to start circulating petrol etc etc again.
Title: Re: Uneven Idle - lpg related??
Post by: Martin_1962 on 05 October 2006, 13:02:48
Pipe from cam cover to inlet manifold - have you checked it is all clean including the jet into the manifold?
Title: Re: Uneven Idle - lpg related??
Post by: Taxi_Driver on 05 October 2006, 15:37:06
Im pretty certain that even tho its a facelift, if its got a 2.0 then you can still do the paperclip test

Its only the FBW's you carnt.
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 05 October 2006, 16:34:50
Thanks guys, will try paperclip test tomorrow and report back. I've checked all breathers and there inlet pipes, all is clear. One of mates suggested that it sounded like it was injector related. I'm going to change the o rings (really should have done that when I fitted injectors and try an injector cleaner as well.
next progress report tomorrow  ;)

cheers jim
Title: Re: Uneven Idle - lpg related??
Post by: Markie on 05 October 2006, 16:41:36
Looking forward to it Jim, dont worry you will get there - you`ve done a magnificent job already  :)
Title: Re: Uneven Idle - lpg related??
Post by: Craig_R on 05 October 2006, 20:26:23
make 100 % sure the throttle body is nice and clean and that nasty little tiny small breather hole in the throttle body is clean as it will make a difference if its blocked or alittle clogged.

Do you have the same problem for high revs on petrol as on GAS to my knowlage things appear on GAS before petrol.

The MOT you asked about YEP you can put in through on GAS but its not recomemded as its best to have it pass on petrol I read it somewhere online ill have to dig out the link if i can find it

Craig
Title: Re: Uneven Idle - lpg related??
Post by: Taxi_Driver on 05 October 2006, 20:59:21
Quote
The MOT you asked about YEP you can put in through on GAS but its not recomemded as its best to have it pass on petrol I read it somewhere online ill have to dig out the link if i can find it

Craig

MOT on lpg doesnt really matter.....ive had my 3 lpg cars tested while running on lpg.....mot station just lowers the figures when testing it.....all have passed....with flying colours  :) .....in fact according to the figures...on the printouts...running on lpg when the do the test...they have passed easily  ;)
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 06 October 2006, 12:44:41
This morning, I did the paperclip test but I'm getting some weird readings. My EMl flashes 10 times before giving some other codes. If I ignore the 10, I did get 1 then 3 which equates to the lambda sensor i think. I'll wait until I replace the lpg lambda this afternoon and try the test again.
I also changed the injector assembly for my original one (still old seals as Vx cant get them till Tuesday  >:()  and it made no difference. I tried disconnecting the idle control valve with the car running and the idle smoothed out perfectly! reconnected it and it starts fluctuating again. All in all, a bit of a weird day in the garage, any ideas folks  ::)

Cheers Jim  
Title: Re: Uneven Idle - lpg related??
Post by: nixoro on 06 October 2006, 12:55:25
Quote
This morning, I did the paperclip test but I'm getting some weird readings. My EMl flashes 10 times before giving some other codes. If I ignore the 10, I did get 1 then 3 which equates to the lambda sensor i think. I'll wait until I replace the lpg lambda this afternoon and try the test again.
I also changed the injector assembly for my original one (still old seals as Vx cant get them till Tuesday  >:()  and it made no difference. I tried disconnecting the idle control valve with the car running and the idle smoothed out perfectly! reconnected it and it starts fluctuating again. All in all, a bit of a weird day in the garage, any ideas folks  ::)

Cheers Jim  

The ten flashes with mine result to a 0 does it flash ten times after giving the code aswell only sounds like your car has a similar ecu (simtec 56.5) to mine which uses the P codes for example 0130 which is for the lambda sensor.
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 06 October 2006, 13:14:09
Thanks nixoro, sounds like mine is on P codes, that would then make the code flashes make sense. I'll connect the new lambda when it arrives this afternoon, do the reset and try again.

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: nixoro on 06 October 2006, 13:24:00
Quote
Thanks nixoro, sounds like mine is on P codes, that would then make the code flashes make sense. I'll connect the new lambda when it arrives this afternoon, do the reset and try again.

Cheers Jim

Have you managed to get your hands on a code reader as the codes will clear after 20 good starts as far as I'm aware.

HTH
Title: Re: Uneven Idle - lpg related??
Post by: Markie on 06 October 2006, 13:28:07
source a known good icv and see if this sorts the issue..
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 06 October 2006, 17:49:19
Okay guys, I fitted my new lambda for the lpg so that side of things is fine. Tried another ICV that I borrowed from the breakers, still an unknown quantity but no difference to the fluctuating idle. I refitted one of my ones that I had soaking in carb cleaner all afternoon but still no joy. both of my original ICV's look very clean internally anyway.
Next up was the paperclip test. It only worked with the ignition on and the car not running. codes were as follows: 0130 (Oxygen Sensor?)
                0505 (haven't got a clue?)
                0110 (Intake air sensor?)
                0100 (immobiliser control unit?)
I tried resetting the eml by turning the ignition on and off 30 times as per the link on the paperclip FAQ but nothing happenend. Should this be done with the paperclip in or out?

To reiterate, the car starts great, runs fine until warmed up when the idle starts fluctuating. Disconnect the idle control valve and the car now cuts out. The idle speed is perfect on lpg.
Any thoughts??

Cheers Jim
                  
Title: Re: Uneven Idle - lpg related??
Post by: Markie on 06 October 2006, 18:08:44
Kind of stumped, but thinking out aloud......

Idle fine on lpg but lumpy idle of fuel.......so what does the LPG not use the fuel does use......whats the idle bypassing on lpg..... :-/
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 06 October 2006, 18:37:27
That's what I've been trying to figure out! The only thing I can come up with is the petrol injectors but as I changed them over this morning, I don't think it's related to that either. Also, the idle is fine when the car is cold....

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: CaptainZok on 06 October 2006, 18:48:52
Could this be something to do with the lambda sensor?
Wonder if theres a way to tell when the sensors switch from open loop to closed loop and therefore see if thats when the idle falters.
Title: Re: Uneven Idle - lpg related??
Post by: Taxi_Driver on 06 October 2006, 18:55:11
Its usually the other way around!! LPG will find fault with an engine that petrol doesnt......Only thing i can come up with is possibly an air leak.....lpg may be running rich a bit.....so with the extra air...it doesnt notice.... :-/

Those codes you have may be cause of the engine change or be old ones......be good if you could reset them and see which ones come back  :)
Title: Re: Uneven Idle - lpg related??
Post by: Martin_1962 on 06 October 2006, 20:17:27
THis sounds like injectors, shove redex ect through them.

If fine on gas at least not serious
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 06 October 2006, 21:35:30
I'm going to have another fiddle tomorrow and if i can't find anything, I'll wait until after the mot on Wednesday when I can give it a good run and see what happens.

Cheers, Jim
Title: Re: Uneven Idle - lpg related??
Post by: Craig_R on 06 October 2006, 21:43:46
just a quick thought the Fuel filter

The LPG will have a separate fuel filter

Craig
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 06 October 2006, 21:53:51
Hi Craig, I was going to change the petrol filter tomorrow as well, even boght the fancy pliers to make life easier  :)

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 07 October 2006, 13:02:16
Todays progress report  ;)

Changed the fuel filter and decided to remove the throttle body and fit my spare, all freshly cleaned up of course. I also cleaned the small pipe that screws into the manifold just below the throttle body and connects to the cam cover.
The idle is better, stays steady when warm until you give it a rev and it then fluctuates for a about 5 - 10 seconds before smoothing out again. EML is still on!

I'm thinking about the following course of action. Leave as is until I've mot'd the car and driven it about for a week or so. that should give the ecu time to clear any old codes and leave me with the problem code. I'm pretty certain it's related to the idle management system, is there any other bits of that to check? All vacuum hoses are on and in good condition and from what I can see, they are all in the right place.
getting there but any thoughts??  ;)

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: JasonH on 08 October 2006, 09:08:20
I make those codes as:

0130 Oxygen Sensor Malfunction
0505 Idle Control System Malfunction
0110 Air Intake Temperature Sensor
0100 MAF Malfunction

I'd say your problem is with the air intake (perhaps the connectors or wiring).
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 08 October 2006, 11:53:57
Hi Jason,
             I started the car once when I'd forgot to connect the air intake and maf sensors so I think that is why I've got those codes. Lambda was broken for the LPG so I assume that would trigger that one too. That leaves me with the idle control system. going to run the car for a while to try and clear the obsolete codes and see what I'm left with!

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: nixoro on 09 October 2006, 13:19:52
Having read back have you cleaned the rear crank breather pipe only this can cause idle problems aswell, cleaned mine out a month or so ago when idle was abit rocky and its been fine ever since, mine was properly coated with coaked on crud and even cleaned the oil seperator not ideal but has helped alot (needs replacing).

Reason I ask is you mention you changed the throttle body and have cleaned the front breathers but no mention of the rear crank breather.
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 09 October 2006, 18:31:41
Hi Nixoro,
              the engine I got had the oil seperator broken when they took it out. I had a look at a couple of other cars in the breakers and they just had a rubber pipe instead of the seperator so I've just fitted that. It was nice and clean.
I'll see how it goes after the mot but as the EML is still lit, there must be some issue with it.

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: nixoro on 10 October 2006, 10:29:07
Quote
Hi Nixoro,
              the engine I got had the oil seperator broken when they took it out. I had a look at a couple of other cars in the breakers and they just had a rubber pipe instead of the seperator so I've just fitted that. It was nice and clean.
I'll see how it goes after the mot but as the EML is still lit, there must be some issue with it.

Cheers Jim

Ok rules that possibliity out, so you say the Idle is mixed up/down when on petrol but steady when on LPG have you confirmed both lambda sensors are working, I'm guessing it should flick between one or the other when changing fuels.

Have you checked for any damaged cabling from the ICV just wondering whether a frayed cable could be causing the idle isssue (0505 Idle Control System Malfunction).

Have you checked all the joins and breathers are on tight?
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 10 October 2006, 14:59:40
Hi Nixoro,
              I've checked all the breathers etc but not 100% sure about the car's own lambda sensor. I raided this from the car that donated it engine and it looks in good condition. Not sure how to check it tho hence the waiting until the old codes are cleared from the ecu.
One thing I did notice while sitting in the car with engine running today. The idle was nice and steady, then I pressed the brake pedal to engage drive. The idle started to fluctuate. That would point to a vacuum problem somewhere. I'll recheck all the vacuum pipes tomorow before the mot.

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: Markie on 10 October 2006, 21:50:01
well its definatly breathing/ filtration problems or air leaks........

not that this hep at this stage as it means fuel, fuel filters, pipes to and box/ sensor relating to air intake....

mot day tomorrow?
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 11 October 2006, 17:05:21
Changed the injector seals today before the mot and double checked call the vacuum pipes were okay. EML still on and still no difference  :( I noticed that I couldn't blow or suck through the vacuum pipe that goes to the pump & filter located in the left hand inner wing behind the wheel arch liner. Guess that's worth an investigation tomorrow.

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: HI2DVY on 12 October 2006, 22:13:40
C'mon Jim, put us out our suspenders... did it pass the MOT??? :y
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 12 October 2006, 23:39:37
Hi H12DVY, yes it passed no problems, posted a thread on the general chat yesterday  :) got it taxed today and have been enjoying cruising around in Omega luxury The car seems to be running great on lpg and petrol but I've still to get to the bottom of the idle problem  :(

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: HI2DVY on 13 October 2006, 00:47:34
Hi Jim,

Great news about the MOT - and glad to see that you've got your meega running. Its been quite a project and we've all been following your progress with interest!

Can't help with the idle problem I'm afraid but I'm really interested in the LPG performance. Was the car originally a dualfuel or has it been converted? If so where was the tank put and how big is it? I'm thinking of having mine converted because of the mileage I'm doing.

Dave
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 13 October 2006, 10:12:11
Hi Dave,
            my car was converted about 5 years ago from what I can make out from an LPG approved installer. I did try to contact them for some details but the've just recently gone out of bussiness. My tank is in the spare wheel well of the estate but is about 2.5" higher than the boot floor. This was levelled with some plywood, a job that I'm going to redo today as it wasn't very neat.
Mine is only the single point injection which is meant to be less efficient than the modern multipoint but I can honestly say, I've not noticed the difference between running on fuel & lpg. Mind you, I've only driven the car for 1 day so far  ::) I'll keep you posted on how much my weekly fuel bill drops. It would probably be worth speaking to some of the other guys on here who have had lpg conversions for a while and see what they think of them.

Cheers Jim
Title: Re: Uneven Idle - lpg related??
Post by: mijfife on 14 October 2006, 16:46:06
I rechecked my codes with the trusty paperclip today to see if any of the old ones had cleared. I'm now left with two out of the original four but not the two I expected!  ::)
0130 is still there, indicating a lambda related fault and 0100 MAF sensor.

Is there any checks I can do with a multimeter to test the Lambda? I've got a couple of 4 wire universal ones sitting. Wires are two white, 1 black and 1 grey. how do these colours correspond to the Vauxhall wiring? I thought I might just try one to see if it makes any difference.

Cheers, Jim