5L rough idle/running problem

[oosty85]

ok i need some quick advice on a problem my car has before tomorrow as it's due for a blue slip..

It's been off the road for a few months and the top manifold has been ripped off to put new inlet manifold gaskets and rocker gaskets on etc etc. it also has some old hsv headers put on it also.
so we put it all together, wire everything up nice and tight..start it up yesterday for first time and it is running like an absolute dog, black smoke everywhere for the first 30 seconds everytime and then the 'CHECK ENGINE' light comes on and it pumps the revs up and idles like a dream!! it's like the computer isnt giving it enough fuel until the light comes on and it adjusts...

as soon as u touch the throttle or enguage a gear (auto), the engine light turns off and it returns to trying to stall and puffs the black smoke again..

my first thought was oxy sensor on the header, but it is wired up just like it used to be on factory exhaust manifold..about 100mm further back on car now tho.. would this make a difference that the computer is angry about????

i'm out of ideas as everything is on correctly and it ran PERFECT before the little rebuild.

if u have an idea or experienced same problem, please throw me some suggestions!!

cheers josh

[strgas]

check your map sensor vac line and engine block earth connection ???

[oosty85]

i will check the map and vac cheers. but engine block earth..where's that?

buying some new leads this arvo, as it has new plugs but original leads since i bought it like 2 years ago. but they were fine up until we pulled engine apart.. thanks

[hako]

Double check the spark plugs wires aren't on the wrong plugs....also check air filter and all vacuum lines.

[levymetal]

i mixed up the leads once, i can tell you it wasn't a pretty story. huuuge BANGBANGBANGBANGBANG and i don't think it would have actually run at all

if anything, black smoke means it's running too rich.

check your error codes to see what that engine light is actually telling you anyway.
Checking error codes VR/VS (Revised)

apparently some cars have problems when the oxy sensor is too far back as it doesn't get hot enough to work. i've got hsv headers on my car though without any problems at all though. and if it does it from cold then it kinda rules out that anyway

[oosty85]

thanks for the help fella's.. i checked the vacuum line to map sensor like 'strgas' said and it was missing..found it under the manifold tucked away. plugged it on and it took about 4 goes to start it and then was perfect!! was so relieved!!

had a scare tonite tho because i presure washed in the engine bay to get rid of old grease and oil and she wouldn't start.... took about 2 hrs of air compressing and eventually kicked over..PHEW!! blue slip tomorrow morning, fingers crossed!!

cheers

[greenfoam]

I was JUST about to post that it was 100% the map line, my mate came around last week with his car doing the exact same thing . Good to see you figured it out anyway

[oosty85]

haha yeah i guess once it happens once, u will recognise the symptoms straight up the next time it happens..cheers!!

anyways, the old gal passed blue slip with flying colours today, so its all registered and insured :-)


one thing that i must check though, is the weight range the guy put my car in...he's got it down as like 1510kgs, which costs like $100 more for rego!! anyone know off the top of their head wat a 93 vr calais 5L sedan weighs?? i'll dig through some old papers and try find it anyway