Vauxhall Owners Forum banner

C20XE hesitation - HELP!!!

5.3K views 15 replies 9 participants last post by  astraderv  
#1 ·
Hi guys - I now have a hesitational (is that a word?) problem. Its a C20XE red top engine in my Astra -

new Vaux plugs
new Mafco leads
new dizzy cap & rotor
new fuel filter
induction kit changed for stock box & new filter
no fault codes stored or light on.

Usually it's fine then suddenly, when I put me foot down it starts to hold back big stylee & miss slightly. This can happen at any point in the journey (hot or cold). When it does happen, it doesn't 'clear' - the problem stays there until u stop & switch off. Oh, the other thing I notice is - when it happens, the exhaust note/induction growl is louder but maybe this is 'cos I'm putting me foot down more to compensate? I'm stuck - all multiplugs & wiring etc seems fine

Any ideas anyone?

Thanx, Dave:)

One other thing - when started from cold, it sometimes tries to die - I have to rev it to stop it stalling. Connected?
 
#2 ·
I might be way off the mark here (probably will be).

But the only other things I can think of is to:

1. Clean your idle control valve
2. Check your Air Flow Meter and pipes
3. Distributor

Apart from that i'm stuck.

Although my car does have the odd attack of trying to stall when setting off from cold. Never when warm though.:confused:

Adam
 
#4 ·
The best thing to do is to get someone to swap for 5 minutes so you can test it.

I swapped mine and Carlp's around for a few minutes to check mine. It's only a 2 minute job.

Unfortunately:confused: it wasn't my air flow meter but I think it may be the rubber gasket under the SFI box letting air through. I'll just put some rubber sealant or something on it.
 
#5 ·
Madras_GSI said:
The best thing to do is to get someone to swap for 5 minutes so you can test it.

I swapped mine and Carlp's around for a few minutes to check mine. It's only a 2 minute job.

Unfortunately:confused: it wasn't my air flow meter but I think it may be the rubber gasket under the SFI box letting air through. I'll just put some rubber sealant or something on it.
Get yourself a Corrado mate - you know you wanna !!! lmao lmao
 
#6 ·
Hmmmm,

Well, you make think my advice worthless on the fact that i've not gone into business as a mechanic myself but as you are looking for any idea.....


When it comes to any running problem especially one that manifests in such a random fashion my first thought is gammy fuel pump relay. While the definition of a faulty relay is something along the lines of "an increasing tendency for the engine NOT to start over time especially when hot..." it may cause other effects.

While not being exactly the symptom(s) you descibe if its on its way out it will probably work intermittently and may be manifest as a problem when you put your foot down. When you do this the fuel requirement 'jumps' to a larger figure (rather then a steady progression) and may be causing a lag in fuelling. I realise this does not answer why you have to switch off and reset - i'd take mine out and see if the problem manifests on all rates of acceleration from smooth gradual accell to full on foot-f****g.

I would also be suspicious of the fuel pump and suggest that maybe its not up to the job of providing flow rates sufficient for all throttle positions.

Another one is the throttle position switch (left side of inlet manifold underneath sfi box). This works on a variable resistor principle (like a light switch dimmer) where the mechanical motion of your foot moves a contact across another contact which then gets translated by the ecu as the load and thus how much fuel to supply. If the contacts are worn/corroded you wont get a smooth signal to the ecu which will show as a running problem - i.e. if half of it was worn from half throttle to full, when you give it some hammer, it needs to use the broken part of the contact: no signal, ecu goes "huh?" and it wont get any faster. If it sticks (the contact) it also wont reset i.e you have to stop the engine and reset it that way

Erm, what else...

But it could(and i know you've heard this and i don't mean to make you mad) be a whole host of things. However it must be either fuel, air or spark - so the rest of it is backtracking i'm afraid.

Did you repalce all your new parts at the same time? I presume it has only started doing this after you replaced them. Would you be willing to replace the old parts sequentially to see if the problem eliminates itself and so narrow the possibilities? But if it only occurs after the replacement parts you have probably disturbed something (fuel pump perhaps?)

Give it a run out and gradually increase your rate of acceleration and see where the problem manifests though before taking anything apart!!!!

Er, well as i say, i'm no expert as otherwise why aren't i in the business myself but i've come across similar problems before especially the fuel pump relay one (i carry one at all times in the glovebox)

Post your results mate as i love a problem!


Oberleutnant Begbie, PanzerAstra Commander
 
#10 ·
Madras_GSI said:


Thats IT!!!!!! I'm gonna put in my profile that I drive the girlfriends corrado too !!!!! lmao

Jesus Begbie,

Any word count by microsoft gen??

You should write a book! :) :D
lmao lmao lmao But the missus can ban you from driving it eh? LOL :D

As much as I love my Corrado - My Mk1 Astra GTE will always be my 'boy racer mobile' *:)

Thinking of selling the MK1 - any gen on how much it worth then?

Might get a 16V MK2 *:)
 
#11 ·
Thanx for your idea's chaps! I shall try them all and report back WHEN I have fixed the problem! (note use of the word 'WHEN')

Begbie - I never think anyone's advice is worthless - on the contrary, I have always received good advice here from everybody, of which I'm VERY gratefull - the more the better!! You certainly sound like you kno what you're talking about, too!:)

Redxiii - I'm not running a cat - it's got a Scorpion Gp A stainless system, but ta anyway!

Watch this space.............................lmao

regards, Dave
 
#12 ·
My mates does the same thing!!

Its usually one of the following...............

1. Head-gasket - water leaking into cylinders and doing the dirty on ya - do a compression test!!

2. Fuel filter blocked - er.... replace it

3. Dizzy cap worn - er......replace that as well (they eat dizzy's!!)

4. ECU prob - try disconnecting the battery overnight to reset it

5. Fuel pressure regulator sha66ed - get it tested or replace


Well thats my Top 5 for this week, my old system used to do it occasionally but it was usually the dizzy cap for some reason!! The new system don't do it though!! he he www.sdsefi.com system muahahahahaha
 
#13 ·
Hey mate! I "used" to have this problem. (keeping my fingers crossed) But mine hesitated when the engine is hot and under load (aircon). I replaced:

crankshaft sensor
knock sensor
coolant temp sensor
cleaned throttle body, intake manifold
replaced intake manifold gasket
fuel filter
fuel pump and relay

The problem was still there after all these!! :eek:

Finally a mech told me not to use Shell Vpower (i think its called optimax over there) as it might cause detonation (due to the heavy vapron boosters) which causes the ignition to retard.

and to switch back to normal plugs from Denso iridium ones. So far so good, still keeping my fingers crossed ;)

Hope u can get some pointers from here
 
#15 ·
i had this exact problem until last night, those symptoms are dead on.
the wire from the crankshaft sensor had come too close/touched the exhaust manifold and melted thru the insulator on it.
it was giving tc 31 and 36 i think. i cleared the codes, changed the sensor and now it is running better than it ever did, and i tied back the wire this time:rolleyes:

def worth a look, it solved my gte16v
 
#16 ·
Sorry I took so long to reply but -

Astranut - me 'zorst has a 2.5" internal diameter, has CAT replacement pipe and is classed as GP 'A'.

So, yeah it's a bit bigger than yours but not by that much. Perhaps u need bigger still with a blower?

Jhinchy - I've had exactly the same problem - the crank sensor wire had nearly burnt through by touching the manifold. I changed it but DIDN'T disconnect the battery. P'raps I need to!!

regards, Astraderv.:beer: