Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: philsteward on 06 January 2013, 22:38:12
-
Hi all,
Managed to get the car running okay after the head gasket change and the misfire as mentioned in this previous thread - http://www.omegaowners.com/forum/index.php?topic=110551.msg1387689#msg1387689 (http://www.omegaowners.com/forum/index.php?topic=110551.msg1387689#msg1387689)
Embarrassingly...it was the injector plug which had come loose from the LPG injector loom, so easy fix!
Taken the car for a run and it worked fine, pulled okay, no hesitation and all good, temp gauge did not get above 80 though (with air con on) so I think either the thermostat has got stuck open by some gunk or failed.
Now the issues...after the run (a break of an hour or two) went back to the car and started it but it was showing the car with the spanner light and idling about 1250rpm and the accelerator was not responding. Turned the engine off, immediately restarted it and light out, idling normal about 800rpm and accelerator working fine. Drove home, all okay. Tried again at home, the same, alternately swapping between working and not.
Checked the codes and the following was shown as pending:
P1550 DTC definitions not found
P1526 Minimum throttle position not learned
P1525 Throttle body service required
Cleared these and found they come on as soon as you put the ignition on, but only when it starts up with the fault.
Whilst doing the head gasket change, also cleaned out the cam cover, all breathers, adv/retard tube, throttle body, egr (blanked). Have just checked all the breathers again and found the following:
Rear nearside crank breather is blowing out the pipe from the crank side, is also blowing out the cam cover - there is an alarming amount of water (white) residue in the pipe.
Front offside small breather is blowing from the cam cover and sucking nicely from the pipe, also a white build up.
Front offside large breather is blowing from the cam cover and nothing from the pipe - if you blow down the pipe you can hear the engine rev drop a little as too much air going in so pipe not blocked.
Adv/retard small plastic pipe is sucking nicely from the pipe end, nothing on the diaphragm side
The other vacuum pipe on the throttle body has no pressure, but the suck is very hard into the throttle body, the engine stalls when it is removed, and runs very lumpy if started without the pipe connected.
There is a lot of back pressure when you take the filler cap off with engine idling, more than I would expect.
Sorry for the ramble, but trying to give as much info as possible. Where do I start? I know I need to clear all the breathers again, but they are not blocked, just got the white mayo in them. Probably from water contamination into the oil during the HG change and maybe some residue in the cam cover when I cleaned it out.
Any help gratefully received...cheers ???
-
If you didn't give it new oil and filter after the headgasket change, do so before you run it again.
Test thermostat by starting from cold and observing temperature of top rad hose during first few minutes running.
-
If you didn't give it new oil and filter after the headgasket change, do so before you run it again.
Test thermostat by starting from cold and observing temperature of top rad hose during first few minutes running.
Oil changed after HG, and coolant obviously, will be changed again once I have done 100miles or so. Will check the thermostat in that way when I get a chance, however it is the unusual codes I have no idea about.
Cheers
-
The codes all relate to the electronic throttle control so, in the first instance, make sure the throttle body is clean and that the wiring to it is not damaged or caught and that the connector is fully home.
-
The codes all relate to the electronic throttle control so, in the first instance, make sure the throttle body is clean and that the wiring to it is not damaged or caught and that the connector is fully home.
Thanks Kevin, checked the throttle body yesterday, removed it and re cleaned it, checked it was seated okay, butterfly lightly oiled, smooth operation, not quite closed when ignition off, twitches when ignition turned on. Checked the connector is fully home, wiring looks okay but it very quickly disappears into the loom, any guide on which way it goes? Does it go to the ECU from there? Is there another connector in its line?
Cheers
-
The codes you are seeing can occur when you have an air leak.
Check and remedy any air leaks first.
-
The codes you are seeing can occur when you have an air leak.
Check and remedy any air leaks first.
Thanks Mark, I have visually checked the 3 breather pipes, the adv/retard tube & the remaining vacuum tube on the throttle body and have found no splits in the pipes, I have run my hand over them as best I can when engine running and felt nothing as well.
Is there anywhere else there could be an air leak? The intake is fine as well, and all clamps are secure.
-
The codes you are seeing can occur when you have an air leak.
Check and remedy any air leaks first.
Thanks Mark, I have visually checked the 3 breather pipes, the adv/retard tube & the remaining vacuum tube on the throttle body and have found no splits in the pipes, I have run my hand over them as best I can when engine running and felt nothing as well.
Is there anywhere else there could be an air leak? The intake is fine as well, and all clamps are secure.
one way to test for leaks is to lightly spray around the pipes/plenum etc with carb cleaner whilst the engine is running at tick-over .. if the engine speed suddenly increases the carb cleaner has been drawn in and is being burned as unmetered fuel !! you have just found the leak .. :) Sort that out then wipe down with a piece of kitchen roll .. result .. no leaks and a nice clean engine :)
-
The codes you are seeing can occur when you have an air leak.
Check and remedy any air leaks first.
Thanks Mark, I have visually checked the 3 breather pipes, the adv/retard tube & the remaining vacuum tube on the throttle body and have found no splits in the pipes, I have run my hand over them as best I can when engine running and felt nothing as well.
Is there anywhere else there could be an air leak? The intake is fine as well, and all clamps are secure.
one way to test for leaks is to lightly spray around the pipes/plenum etc with carb cleaner whilst the engine is running at tick-over .. if the engine speed suddenly increases the carb cleaner has been drawn in and is being burned as unmetered fuel !! you have just found the leak .. :) Sort that out then wipe down with a piece of kitchen roll .. result .. no leaks and a nice clean engine :)
Excellent suggestion, will try that, thanks! Assume it is leaks in the intake side of the engine I am looking for, anything between the MAF and the inlet manifold - including the inlet manifold gasket & in my case I assume the LPG pipes as well?
Cheers
-
The codes you are seeing can occur when you have an air leak.
Check and remedy any air leaks first.
Thanks Mark, I have visually checked the 3 breather pipes, the adv/retard tube & the remaining vacuum tube on the throttle body and have found no splits in the pipes, I have run my hand over them as best I can when engine running and felt nothing as well.
Is there anywhere else there could be an air leak? The intake is fine as well, and all clamps are secure.
one way to test for leaks is to lightly spray around the pipes/plenum etc with carb cleaner whilst the engine is running at tick-over .. if the engine speed suddenly increases the carb cleaner has been drawn in and is being burned as unmetered fuel !! you have just found the leak .. :) Sort that out then wipe down with a piece of kitchen roll .. result .. no leaks and a nice clean engine :)
Excellent suggestion, will try that, thanks! Assume it is leaks in the intake side of the engine I am looking for, anything between the MAF and the inlet manifold - including the inlet manifold gasket & in my case I assume the LPG pipes as well?
Cheers
All around all pipes IMHO .. including all those at the back of the engine under the scuttle ... quite a few vac pipes there that involve things as diverse as the brakes and air conditioning !! Any air leak there will affect lots of things !!
I remember Lizzie (I think) having a major problem with the top hat seal under the plenum breather leaking.
Air leaks are a pain in general !!
-
An update I have checked all vacuum pipes for leaks - not found any! Checked all connections again - all seem fine no obvious problems. At a complete loss now.
Wondering whether it could be a faulty cam sensor & would it be helpful to get it into tech 2?
Thanks in advance for your help
-
No, probably not cam sensor at this stage and yes, some diagnosis with a Tech 2 would certainly be helpful. :y
-
Thought I ought to update you all, tonight in-4C I have just finished changing the throttle body for a spare and hey presto the car is working fine!
Taken it for a short test drive and no error codes pulled nice and the back pressure seems to have reduced as well.
Many thanks for all your help with it, another problem solved!
-
Thought I ought to update you all, tonight in-4C I have just finished changing the throttle body for a spare and hey presto the car is working fine!
Taken it for a short test drive and no error codes pulled nice and the back pressure seems to have reduced as well.
Many thanks for all your help with it, another problem solved!
perhaps a faulty TPS?
-
What's a TPS?
-
Throttle position sensor.
-
Is that integral to the throttle body then? How can it be damaged, or is it like a light bulb which can just go?
-
Glad to hear it's sorted. :y
TPS is throttle position sensor. A separate sensor on cars with a throttle cable. On drive by wire cars it's integrated into the throttle body, and you actually have dual TPSs for redundancy on a drive by wire car, due to the safety implications of it going wrong!
-
Glad to hear it's sorted. :y
TPS is throttle position sensor. A separate sensor on cars with a throttle cable. On drive by wire cars it's integrated into the throttle body, and you actually have dual TPSs for redundancy on a drive by wire car, due to the safety implications of it going wrong!
Might that explain it working on alternate start ups?