opel corsa flat spot on pull away

[xsel]

Hi all

I hope that one of you have had this problem and have been able to solve it.

My opel corsa utility 1.4 2006 has this strange symptom/s when warm,
from 1/4 on the temperature gauge:
On pull away, it has a hestitation,and then moves ahead smoothly.
OR it misses a few times and then smooths out at 2500rpm,
OR the car jerks 2 or 3 times as I pull away.
OR any of the above 4 and then the car struggles with acceleration performance until about 2500rpm, when the eneygy comes back.

When cold the car ,after starting,and then pushing peddle to reverse out the driveway, the revs would drop and sometimes cut out.
This stopped after a software upgrade by REEDS.
BUT when cold the car still has a flat spot on pullaway.
When cold the car pulls with energy,smoothly,just the pullaway flat spot.
When cold, no missing,no jerks.

What I have done sofar, apart from the software upgrade.
Replaced the idle valve solenoid thingy on top of the throttle body.
Replaced oil,oil,air and petrol filters,plugs(NGK BPR5EY),Bogicords.

I also took the bakkie to a specialist car tuner in Milnerton Koeberg Road.
and they could not fix it,also saying no computer errors,a dyno tune was done as well,which they said looked fine.

I have ordered the OP-COM diagnostic to see what the car computer has to say for myself, since the "professionals" havent been able to fix it.

Possible things to do:compression test,fuel pressure test.
Over the top things to do - order the EFFI from USA that connects to the oxygen sensor on the exhaust to trick the computer to supply more petrol to the injectors.
Find someone who can re-program the computer to give more petrol from idle to 2500rpm.

What else can you suggest I look at?

Thanx/Peter

 

[LCBXX]

Spark Plugs

 

[Nocturnity]

Aye, could be plugs. Also, something similar happened on my Opel Coupe and it was fixed by replacing the coil pack and fuel-injectors.

 

[rotto]

I have a problem with my Corsa when the engine is hot. Say I drove for a while, then stop for about 15-20 mins. When I try to start I have to turn the key 2 or 3 times before the car actually starts. This does not happen everytime though, but most of the times. But when the engine is cold, say it stood overnight or so, the car always starts first time everytime, no problem.
I have asked a mechanic to look at it and also took it to Williams Hunt, but it still does it. And I have no idea why.

 

[Keeper]

Check if there isn't a potato stuck in your exhaust, or the cars.

 

[werner]

have you guys checked for air leaks in the intake bellows? the (pretty common) big plastic thingy form airbox to manifold...

both posters problems sound like a car running very lean, the spark plugs electrodes would be brown and very dry if you want to check.

 

[Nocturnity]

I agree. Also think it's a fuel burning issue. Either too little fuel or too little air. The pipes in the engine also contract/expand with different temperatures so it could be a collapsed airflow pipe, especially when the car is hot. When it contracts, the pipe gets hard end there's an air leak where little cracks form.

 

[Gnome]

Which Corsa is that?

Corsa A, B, C or D? Pic of car if you can't identify.

Single or dual overhead cams? Pic of engine if you can't identify.

What have you changed on the engine so far, if yes what exactly?

There are many things that can cause the symptoms you describe so best cover the bases before going on to what can be wrong.

 

[Frankie]

I'm not familiar with this car, but to me it sounds like a problem with plugs, HT leads or coils.

My car has the dual coil waste spark system and it's very sensitive to the type of plugs, and the gap. The parts stores list a gap of 0.044" for my car, but it runs like cr@p if the gap is > 0.030" (0.75mm).

 

[4cer]

what about the MAF (mass airflow sensor).

it sounds like the car isn't getting the right mix of air with the fuel, and temperature of the air, affects it which makes it seem more reason...

 

[Frankie]

what about the MAF (mass airflow sensor).

it sounds like the car isn't getting the right mix of air with the fuel, and temperature of the air, affects it which makes it seem more reason...

It sure can be, but just like mine and others suggestions, its speculation - it would be best to get it connected to a scanner after confirming things like fuel rail pressure and compression are OK.

"xsel", do you have more info on the scanner "OP-COM diagnostic" you mentioned?

 

[Gnome]

Ignition pack is unlikely to be a issue, the Coil pack has no moving parts and uses a wasted spark configuration, if it's missing then you're running on 2 cylinders, the car would have trouble pulling off never mind just flat spots, if the coilpack is overheating the car would simply stall with a no-spark situation until the coilpack cools down (with possible backfire if you constantly try starting).

Could be fuel pressure but I doubt it.

Depending on the engine (which is why I'd like to see a pic ), it could be the crank pulley, the engine uses a sensor on the crank pulley to determine TDC (it's called a 60-2 wheel), if the crank pulley has been worn down it'll cause the pulley to move around and in effect the timing will be out completely, to fix it you'll need to replace crank gear + crank pulley, while you're at it change the cambelt, idler pulley and water pump since that's all right there anyway.

what about the MAF (mass airflow sensor).

it sounds like the car isn't getting the right mix of air with the fuel, and temperature of the air, affects it which makes it seem more reason...

Corsa's don't use a air mass sensor, a intake air temperature sensor located just before the throttle body, a manifold absolute pressure sensor is used to determine the amount of air.

Both the sensor are very reliable and unlikely to be the problem but if they've been fiddled with that can cause a issue.

Also if any sensor is not working the engine light will go on.


EDIT: I read your post on Opel Owners Club, there where some details you posted there you didn't post here like the car missing, etc. Perhaps you should borrow a coilpack and test with that because when they start going they work while their still cold and then suddenly you have problems, I bought a new one from Goldwagen for R500 the other day so you should give them a try, GM original will set you back around R2k. Still double check the crank gear!

 

[xsel]

OP-COM

Hi

The OP-COM is an OPEL specific scanner.
2 local suppliers:
http://www.obdsa.com/opcom.htm R2500
http://www.uiftech.co.za/OP-COM.html R1450

I felt it was a bit pricey so got one off ebay for R500 including shipping.
I am still waiting to find out if I will actually get it, but I thought I will take a chance.

UPDATE:HongKong Postal website tracking says it was posted 8 NOV.
So it looks like I am getting something !!!

Pete

 

[xsel]

Gnome, I will see what I can do about a photo tomorrow.
I plan to get a 2nd hand TPS and Temp sensor tomorrow.
I was also going to get a coil, but your description of how it would behave
don't seem to be my symptoms.

Pete

 

[xsel]

Gnome, my UTE is completely stock.It is the base model, with no mods.
The engine, I am told by a mechanic, is the exact same one as for the 2003 model I used to have before.
I did not know there was a D version.I think mine is a C.
It is the one that came out after the round shaped baby looking corsa.
This one has sharper much more elegant lines.
Just to be clear, it is a bakkie.

Pete

 

[Gnome]

K I know how the UTE looks

Also 2006 is most likely a Corsa C but with all the new Corsa Lite models around it's hard to know.

When you say you're car has a flat spot on pull-away, do you mean when you only feel it when you pull away with throttle fully open (IE. petrol pedal fully down) or always when you pull-away.

Is the engine pinging? You can hear it by turning all noise (IE. Radio) down and then open the window slightly, it'll sound like the word says a pinging noise, kinda like a small rock hitting metal.

Is performance generally down or just on pull away from say stop. Check for that pinging noise.

 

[xsel]

This flat spot is with pullaway part throttle.ie,I want to get to where I want to go faster than most everyone else but not first.
So, pullaway with energy,but not full throttle,not racing.

I didn't get the TPS and temp sensor,because the supplier flapped his mouth without checking if he had stock.

There is no pinking.

I will tell you this though;it has been bothering me for some time,
but I don't know if it is important for this diagnosis.
Quickly going 3/4 throttle and letting go,as the revs come done, there
is a burbling bubbling kind of noise,might even be soft popping,from the engine area.
I cant work out where exactly the noise is coming from.

If there was a micro hole in the exhaust manifold or the part of the exhaust in the engine compartment,would I hear a slight exhaust sound from the engine area.?
Would this micro air hole cause the oxygen sensor to give wrong info to the ecu,resulting in weak fuel mixture,and consequently , my issue described in this thread.?
How do I test if the exhaust does have a micro hole.?

Pete

 

[xsel]

Performance is only sometimes missing up to 2500rpm,whereafter the UTE performance picks up again.
I havent been able to work out what conditions are at the time of the engine bogging down until 2500rpm,so can only say sometimes it happens.
It is only 1.4 with a heavier body than my previous 2003 UTE,so I am not expecting a rocket,but my previous UTE flew so well I blew the head gasket!

 

[xsel]

Here is another local site for the OP-COM diagnostic scanner.
http://cartools.co.za/oscommerce/pr...id=48&osCsid=7e71baeec0623d791c6e7e2c3a067d6b
He wants R1999.
I made a mistake in an earlier post.The uiftech site had no pricing.
The price of R1450 was the price that cartools emailed me,because his webiste first stated R14500,and I emailed him, asking if he had sold any at that price.
Now I see that cartools price has been changed to R1999.

 

[DuCy]

Hi all

I hope that one of you have had this problem and have been able to solve it.

My opel corsa utility 1.4 2006 has this strange symptom/s when warm,
from 1/4 on the temperature gauge:
On pull away, it has a hestitation,and then moves ahead smoothly.
OR it misses a few times and then smooths out at 2500rpm,
OR the car jerks 2 or 3 times as I pull away.
OR any of the above 4 and then the car struggles with acceleration performance until about 2500rpm, when the eneygy comes back.

Wow this exactly similar to what i'm experiencing right now with my Renault Clio III, I'm taking it in for its first 15K service this coming Friday i hope it will be fixed, the car 6 months old.