its got me stumped. can u help

hey guys, my VR has been giving me the sh*ts..was leaking coolant thought it was the headgasket..lucky it was the inlet manifold gasket leaking out the front, took that off replaced it..done...
now the real pickle.

Shes Miss Firing. now its been diagnosed, it didnt pick anything up, we've checked the O2 senser, Idle Throttle sensor, leads are fine, spark plugs are a little on the lean side, reset the computer.....Its missing randomly and only when its warmed up. strange thing is when we took the idle throttle sensor off it ran smooth (just at 2 grand)

anyone got ne ideas on my situation





VR Series 1
- larger pacemaker extractors
- 2.5in straight thru
- custom cold air intake
- k&n filter
- removed bellmouth restrictor

Come on guys!

Someone must have had this problem! I know this car my self worked on it and tryed as far as i can go besides injectors. Its done my head in. :hit: Any ideas or thoughts would be Great.

Really wanna get it running nice agian

Cheers

ED :drink:

I'd be checking your cylinder compression is up to scratch as I had a very slow internal leak in my intake manifold gasket which caused two small cracks in between the valves on one of the heads, was on an ecotec though.

My car had a slight miss every now and then with no other real effects from it so it sounds pretty similar.

You can do a very rough check of your cylinder compression consistency by taking out your fuel pump fuse, or anything that will inhibit your engine from firing, and then simply turning your key and listening to the engine turning over. If it turns over nice and constantly even eg, chugachugachugachuga, then it's probably ok, if it turns over slightly irregularily eg chugachugchugchuuga, you might have a compression issue. Or you could go and buy a cheap cylinder pressure tester from super cheap auto or something.

Otherwise I'd be servicing the injectors.

Cheers
Toa

The vacuum hose at the back of the throttle body is real easy to miss rehooking back up.Also one of the ignition leads might be rs after you took it off to do the manifold job and its finally gone open.Usually at the plug end where it turns 90 degrees.

Thanks Guys!

Thanks boys ill go round and do a compression test later. Might be the inlet manifold gasket where it joins the head. I changed it a few weeks ago as it was F@#$ked and was leaking coolant threw there and out the front of the head.

If anyone else has something it would be great.

Ed

P.S Its not the lead as there were just changed.But thats for the tip. :drink:

update!

so yeh..our compression test last nite didnt go to plan as the thread to the plug is resessed or sum ****...neway we wacked the injectors off last nite for a flow test that should b conducted today or tomorrow....fingers x'd that theyre f'd up, causing my problem. The vacuum hose u were talking about was on...altho i no wat u mean leaving it off cos i did it once n the engine was giving us a engine warning sign at the dash...so yeh. wasnt that..cheers guys ne other ideas would b good

cowz

sounds like u've either got a ****ed plug or lead

wasnt the spark plugs or leads dude...
and now we know that the injectors are fine....damn this thing is $h!tting us...bahhh... :cry:

Are you warped ?

Gudday,
No offense meant with the title !
Did you happen to check that the manifold surfaces where flat ? ( Straight edge and feeler gauges)
Any damage where the water was leaking and was the damage just external ? ( Leakage into the inlet tract as well ).
I worked in a machine shop reconditioning engines for ages and you wouldn't believe the hassles caused by the smallest of defects. :hit:

Cheers.
Pete.

okay - warmed up and missing - vacum hose is leaking or you got a air flow sensor issue - seen it a lot of times - and it drove me nutz :bang: