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Argghhhh Vauxhall XE engine trouble!!
NS Dev - 19/1/07 at 08:34 PM

Argghhh!

Annoying afternoon!!! Need help, now where do I start!

I have a vauxhall XE engine in my seven, and have fitted 45mm Jenvy SF throttle bodies, Jenvey manifold and a diy stainless exhaust manifold.

I have robbed the map (actually the whole ECU! ) from my grasser which was running, and running very well, on a setup virtually the same. (slightly different exhaust manifold and 48mm dcoe type bodies instead of 45mm sf ones)

I figured the map from this would run the other engine pretty well.

From the start, it has not idled very well (well not at all below 1300 revs! ) and I put this down to throttle pot zero position and balancing the throttles up.

I zeroed the pot as well as poss (though it still needs to be on load site 2 for it to idle which is odd) but have yet to confirm that the throttle balance is perfect.

When I tried an old Crypton "carbalancer" on it the needle shot form one end of the scale to the other violently no matter what I did with the damper setting on it!

Anyhoo, took it the the garage today to check the brakes on the rollers and check the emissions..........................

bugger!!!!!!!

CO = 1.2%

HC - 4000ppm!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

what the flipping hell is going on there!!!!!!!!!!!!!!!!!!!!

I checked the fuel pressure, dropping it loads dropped the HC, but only to 3500 then it would not run at all!!

The chap at the garage commented that the engine was making a LOT of induction noise and that he thought that the cam timing might be out, but it is on std cams timed to std marks!!

I have no doubt that the mapping will need to be tweaked for the current exhaust and inlet setup, but being from an extremely similar setup it should be close surely!!!

Anybody got any ideas what could be causing the massive hydrocarbons with minimal CO and total lack of idle, possibly coupled with lots of induction rattle at its current 1500rpm idle?

For once I am stuck for ideas!

the_fbi - 19/1/07 at 08:49 PM

How did you time it up?

As you know the crank pulley can slip on the crank, causing the timing to be out.

Welding rod down the plughole to check what TDC actually is on the crank pulley.

theconrodkid - 19/1/07 at 08:52 PM

how about you have an air leak and its running too rich,the air leak giving it "fast idle"?and the leak making it run weak on 1 or more cyls
as co goes up hc goes down

NS Dev - 19/1/07 at 09:09 PM

quote:
Originally posted by the_fbi
How did you time it up?

As you know the crank pulley can slip on the crank, causing the timing to be out.

Welding rod down the plughole to check what TDC actually is on the crank pulley.


The pulley is keyed so I can't see how that would happen, but basics forst so I will check that the tdc mark is right!

Anybody know

a) whether the mark on an XE crank pulley is at TDC on no 1 pot or if its 10 deg before or something and

b) does anybody have the std XE cam timing numbers?

MkIndy7 - 19/1/07 at 09:25 PM

I'm not sure you'll find the standard cam timeing numbers. I've looked everywhere for them and this is the most informative thing i've found

http://www.sbdev.co.uk/Info_sheets/Camshafts/cam%20timing%20instructions%20-%20with%20pictures.zip

I was looking because mines got vernier pulleys.. but with the standard cams and because the verniers don't have the original cast pointers to line up with the marks on the cam cover you've no way of telling!.

To know weather your in the right ball park for the timeing this extract " When the cams are set the lobes on no.4 cylinder should be facing towards the centre of the engine" sempt a quick way of telling.


Also if it used to have 48's and its now got 45's would there not be less air getting in for the same amount of fuel (as the injectors are still fireing at the same rate)... making it over rich like somebody has suggested and reducing the fuel pressure was kind of a quick fix thus proving it?.

[Edited on 19/1/07 by MkIndy7]

the_fbi - 19/1/07 at 09:36 PM

quote:
Originally posted by NS Dev
The pulley is keyed so I can't see how that would happen, but basics forst so I will check that the tdc mark is right!

Been a few instances of the woodruff failing, shame the pics are missing from this thread.

http://www.migweb.co.uk/forums/vauxhall/mechanical-electrical/183808-xe-let-bottom-pulley-pics-evidence-key-needed-56kers-put-kettle.html

If the keys not snapped, the bottom pointer can also move on the rubber bonded section of the pulley. Pulley off job to be 100% sure.

MikeRJ - 19/1/07 at 09:55 PM

Have you run a compression test on it? Possibly a hydraulic follower(s) stuck and holding a valve open slightly?

martyn_16v - 19/1/07 at 11:24 PM

quote:
Originally posted by MkIndy7
Also if it used to have 48's and its now got 45's would there not be less air getting in for the same amount of fuel (as the injectors are still fireing at the same rate)... making it over rich like somebody has suggested and reducing the fuel pressure was kind of a quick fix thus proving it?


At full chat maybe but at idle a bigger throttle body is going to make bugger all difference, it's not using anywhere near enough air for there to be an appreciable difference in the resistance to flow.

I'd lean towards cam timing, timing marks have been known to be out by a fair bit (haven't had any experience of vauxhalls but VAG engines can be a fair few deg out). Is the spark timing about right as well, I find it fairly east to get muddled wiring up coilpacks

NS Dev - 20/1/07 at 01:39 AM

I'll have a peek at all suggestions cheers folks this am wheem lesss beer

tks - 20/1/07 at 12:43 PM

is the sensor on the toothed wheel
on the same teeth as on the other engine..?

i mean to say that the sensors (VR) should be both on the same position to be able to give it the same setup (result)..

can imagine that it could differ some degrees of spark..timeing etc..

Tks

MikeRJ - 20/1/07 at 01:00 PM

quote:
Originally posted by tks
is the sensor on the toothed wheel
on the same teeth as on the other engine..?


The toothed wheel on these engines is part of the crankshaft inside the engine, so they should be identical.

MikeR - 20/1/07 at 04:32 PM

Spoke to Nat (NS Dev) earlier, cam timing appears spot on. He's now thinking it could be to do with the throttle pot. Didn't have time to chat but i'm sure he'll update later.

stevebubs - 20/1/07 at 06:02 PM

Won't a leak in the exhaust raise the HC?

NS Dev - 20/1/07 at 08:39 PM

Right, some way to being sorted!!!

As usual, never listen to your local garage!!

Cam timing spot on, 2 hrs wasted on that one, but at least i now have something of a triple dial gauge jig!

Results were:

1) alternator not charging despite warning light going off (daihatsu type one, any ideas??) causing low battery after running for a bit causing weak spark and misses at tickover

2) faulty crank VR sensor, giving strange rpm spikes on cranking and at tickover, again causing overfuelling and timing swinging all over the shop

3) throttle pot not zeroed very well, this is a bit chicken and egg, as there are no idle bleeds on the throttle bodies, you have to guess the amount of throttle stop needed for tickover, zero the pot to the map at that position and try it, if it doesn't work, each move of the throttle stop needs the pot moving to keep the pot map correct relative to the fuel and ign maps............i.e. a bit of a pain!!

However it now ticks over, still needs a tad of balancing on the throttles (again much easier with bleeds!!!! )

still seems rich so i think I am going for a rolling road sesh to get it right. The map is close so £150 spent now is prob money well spent!

mickebo - 3/2/07 at 01:53 AM

Using standard `box` ?
Looking for Omex maps

M

NS Dev - 3/2/07 at 10:43 AM

I'm using MBE, but email this chap, he'll have an omex map for an XE engine:

swmotorsport@blueyonder.co.uk

[Edited on 3/2/07 by NS Dev]