Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: JoeRadosavljevich on 13 January 2013, 12:40:39

Title: Hesitation, withdrawal and backfire 2.0 16v
Post by: JoeRadosavljevich on 13 January 2013, 12:40:39
Hi there! How's it going, peeps?

I have a question for you technically inclined people who can contribute to my quest of finding out what could be wrong with my, unfortunately used and abused 1994 (Opel) Omega 2 Litre 16 valve manual transmission. It doesn't have a service history because it has been owned by several young drivers who drove the life out of it but the engine seems to run fine, of course when it manages to run. It has 214 000 kilometers on the clock.

So, after acquiring above mentioned car I started to dig into the problem this car has. The first of all and most obvious is a heavy withdrawal of the vehicle while driving, like someone is feeding a car with a bottle of petrol. You know, put some gas in it and when a car starts dying put some more and so forth OR step on the gas pedal and then release it, step on the gas pedal and then release it... All this happens while I constantly keep my foot on the gas pedal and in gear. Few days ago, fuel pump along with the fuel filter have been replaced but the problem still persists. Of course, there is fuel in the tank but I noticed it builds up pressure when the filler cap is removed.

After asking certain smart people on this forum about the step motor I have found out that the car won't idle due to the failure of the solenoid on the idle control valve. It was sooo rusty so it is no wonder a car wouldn't idle. While unplugged the car idles just above 1000 rpm so I need new idle control valve. Oh well, at least I cleaned the throttle body along with the breather pipes and tiny jet on the bottom of the TB thinking that might solve one problem.

Backfire! Yes, I almost forgot to mention that when a car starts dying and then comes back to life, the whole process is followed by pretty loud backfire and shaking of the car.

I am on my way to do a paperclip test but before that I just feel obligated to help those who are trying to help me by saying what I did check on the car. There is no oil in the spark plug holes (altho there are indicators that there used to be oil), spark plugs are new, mass air flow sensor has been carefully cleaned and air filter has been replaced.

Yeah, temperature gauge doesn't work so I did a little snooping with a mirror and a flashlight on the back of the engine and found out that there is a roung connector on top of the EGR valve, with a 3 tiny holes on it that just hangs around freely. I thought it should be plugged in somewhere but I couldn't find an appropriate place to plug it in...

Any thoughts?
thanks in advance
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: RobG on 13 January 2013, 13:34:49
Quote
temperature gauge doesn't work


(http://images.omegaowners.com/images/guides/2.2_useful_pics/Tempsenders_resize.jpg)
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: Abiton on 13 January 2013, 13:39:53
Nice one Rob. 
The answer to this: "there is a roung connector on top of the EGR valve, with a 3 tiny holes on it that just hangs around freely. I thought it should be plugged in somewhere but I couldn't find an appropriate place to plug it in" is also covered by this picture.

I imagine you are talking about the black thing hanging off an air hose, just near the yellow electrical connector of the EGR?
This does not connect to anything. 
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: Brikhead on 13 January 2013, 14:48:32
Any thoughts?
thanks in advance

Check the timing marks are all lined up.
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: ffcgary1 on 13 January 2013, 14:58:28
First you need to do a full service on the engine, then replace the fuel filter and check for fuel leaks.
 Then replace the plug leads and plugs, or check the plugs you have and make sure they are gapped correctly.
If this does not improve things check for air leaks on the intake side of the engine.
Then check that the MAF is connected properly. I seem to remember that cleaning MAFs is not recommended. Try disconnecting the MAF and see if it improves matters. If it has been neglected in the past then you need to start from a known position, so service first then diagnose.
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: JoeRadosavljevich on 13 January 2013, 19:16:14
Thank you, RobG, Abiton, now I know that the thing should hang freely.
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: JoeRadosavljevich on 15 January 2013, 19:23:53
So, here's what paperclip test had to report.

1 flash then 6 flashes
2-1
5-6
and 9-2

Thoughts?
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: Abiton on 15 January 2013, 19:33:48
http://www.omegaowners.com/forum/index.php?topic=90585.0 for code definitions.

I think you already know that your IACV is sick.

Not sure about TPS and knock sensor codes, never heard of either device playing up, but check connections and wiring as far as possible.

Cam sensor code would tend to indicate that you need a new genuine Vx cam sensor. But again check connections are clean and wiring undamaged first.
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: JoeRadosavljevich on 15 January 2013, 19:47:20
Thank you so much!
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: Entwood on 15 January 2013, 19:49:17
Cam sensor failure can throw up all sorts of other codes as the engine just does not run correctly.

IMHO .. do the Cam Sensor first and see what clears .. as  said .. genuine one only ... no copies/pattern parts  :)
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: JoeRadosavljevich on 15 January 2013, 19:54:02
Oh my goodness.... so many things wrong with the car.
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: mrgreen on 17 January 2013, 18:12:20
I would try going for a run around the block without the fuel cap on if you are getting pressure in the tank as that shouldn't happen! sounds like the valve in the cap is bung and it's starving for fuel.
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: JoeRadosavljevich on 18 January 2013, 17:52:22
I would try going for a run around the block without the fuel cap on if you are getting pressure in the tank as that shouldn't happen! sounds like the valve in the cap is bung and it's starving for fuel.

Yes, indeed it does create pressure while driving, that is an additional problem to overall problems my car has, and will try to drive it without the fuel cap so I'll let you know. Thanks for the comeback.

But the cam sensor really bugs me since I am not able to find a replacement... Have been reading little closely about cam sensors and I think that's the culprit, hesitation and power loss.
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: JoeRadosavljevich on 15 February 2013, 11:15:15
I need opinion from the great minds.

I am still on the road to (Mandalay) fixing many issues my car has but one of the major problems is that the misfire is getting worse when lights/beams and some other electrical components in the car are being switched on. What do you people think?
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: symes on 15 February 2013, 16:14:37
I need opinion from the great minds.

I am still on the road to (Mandalay) fixing many issues my car has but one of the major problems is that the misfire is getting worse when lights/beams and some other electrical components in the car are being switched on. What do you people think?

Harness multi connectors by battery mate-contacts open up and cause all sorts of nightmares IMO  :y
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: K. Womble on 31 May 2013, 07:25:11

I am on my way to do a paperclip test but before that I just feel obligated to help those who are trying to help me by saying what I did check on the car. There is no oil in the spark plug holes (altho there are indicators that there used to be oil), spark plugs are new, mass air flow sensor has been carefully cleaned and air filter has been replaced.

Yeah, temperature gauge doesn't work so I did a little snooping with a mirror and a flashlight (http://www.robustbuy.com/led-lighting-gadgets-led-flashlights-c-505_1027_730.html) on the back of the engine and found out that there is a roung connector on top of the EGR valve, with a 3 tiny holes on it that just hangs around freely. I thought it should be plugged in somewhere but I couldn't find an appropriate place to plug it in...

Any thoughts?
thanks in advance

Can you show us a pic of the connector on top of the EGR valve?

Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: JoeRadosavljevich on 04 June 2013, 17:23:21
Okay people, it has been a while but I am finally back with an update and I am asking for a bit of your time and wisdom.

I did manage to buy a used Siemens camshaft sensor (exactly the same as the old/broken one). I really thought it would cure all the hesitation and misfiring but to no avail! I just fitted a replacement sensor and the engine is acting the same as before. Low gas mileage, backfire and sluggish on the gas pedal. Performance seems to improve a bit while constantly pushing the throttle while driving, though. Paperclip test is still showing a camshaft error code.

Does the computer need some time to ''realise'' that it has just got a new sensor or is it something else?
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: RobG on 04 June 2013, 17:30:25
Okay people, it has been a while but I am finally back with an update and I am asking for a bit of your time and wisdom.

I did manage to buy a used Siemens camshaft sensor (exactly the same as the old/broken one). I really thought it would cure all the hesitation and misfiring but to no avail! I just fitted a replacement sensor and the engine is acting the same as before. Low gas mileage, backfire and sluggish on the gas pedal. Performance seems to improve a bit while constantly pushing the throttle while driving, though. Paperclip test is still showing a camshaft error code.

Does the computer need some time to ''realise'' that it has just got a new sensor or is it something else?
Genuine GM/Opel
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: JoeRadosavljevich on 04 June 2013, 17:37:29
Yes Rob, it is an original, made by Siemens. Or am I wrong?
Title: Re: Hesitation, withdrawal and backfire 2.0 16v
Post by: JoeRadosavljevich on 04 June 2013, 18:48:26
Please people, I can not put into words how much I need your help.

With the new sensor the engine does rotate well past 4500 rpm but with the sensor disconnected it does not.
With the sensor connected, engine computer displays no orange light on the dashboard but the code is still stored as a camshaft sensor fault. The main problem is serious misfire between 1000 and 2000 rpm.
No oil in the plug wells and new leads and spark plugs have been fitted.