Very lumpy from cold

  • Thread starter mynheers_a_pint
  • Start date
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mynheers_a_pint

Guest
Very lumpy from cold- new problem :(

Hi All,

I have a rather tedious problem that seems to be getting worse. Basically, when I start the car it does so normally and will Idle perfectly at about 1300-1400rpm but the moment I touch the accellerator it struggles to rev unless I give it a shed load of throttle. Once I've done that, it seems to respond normally to the throttle but during accelleration the car is very hesitant until it is warm. My initial thought was to replace all the uusual culprits- brand new plugs (Gapped, BCR8ES), new dissy and rotor, newish coil (8 months old), Magnecor leads. However, I still have the issue. A bit of researching tells me it could be the Cold Start valve, however, I gather that usually coincides with a generally high idle as well- my idle is perfectly normal, or seems so (1300-1400 at cold and 8-900 warm). I have no fault codes, double earth on my Z32, perfect compression of ~160 on all 4 (if that would ever be an problem that would cause this) and SARD700cc injectors which were sonically cleaned about 2 years ago.

Can anyone suggest anything that could be the problem? Other than the cold start valve, I was thinking that perhaps an engine temp sensor (surely this would throw up a code?) or maybe the ignition amplifier, though I'm not sure exactly where the ignition amplifier is...

Any other thoughts?

Cheers.
 
Last edited by a moderator:
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mynheers_a_pint

Guest
Ah, ok, bit more reading... could the standard gap on the BCR8ES plugs be the issue?
 
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mynheers_a_pint

Guest
Ignore... Code 34. Anyone got a det sensor spare ? :doh:
 
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danr

Member
from my understanding, double earth on Z32 is pointless and a 'myth'. you only need one of the earth's off the maf (the one spliced into original maf earth). the body/chassis earth isnt required and can cause problems (thanks ed@fusion lol) :_)
 
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mynheers_a_pint

Guest
As above, it's throwing a code 34 so I need to get that sorted first... Chances are, it will solve the problem.
 
PobodY

PobodY

Moderators
Staff member
Yeah, if it thinks you've got DET at idle it will never let you rev it. - Sort that one first.
 
Fusion Ed

Fusion Ed

Active Member
Correct about the z32. No point in double earthing any of them, it connects to the same point internally and so can cause more problems than it solves imo. Just make sure the proper earths are good, but in any case. Sort out the knock code first.
 
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mynheers_a_pint

Guest
Well, I've ordered a new sensor up and am now waiting for it to arrive. Any opinions on driving it as it is? I'm slightly worried and wont be boosting anywhere but i've still got to get home and to and from work tomorrow..!
 
PobodY

PobodY

Moderators
Staff member
I think you'll be OK - if it's limping it's not going to let you drive it hard, but if you keep the revs down it should still pootle about and get you to and from work.
 
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mynheers_a_pint

Guest
it's not limping, that's the thing. bar a lumpy start, the car is boosting without any resistance. It's just a bit sluggish.

At least, when I've been in a car that's in limp mode, it's not revved beyond say 3k rpm, if that's why you mean.
 
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mynheers_a_pint

Guest
balance nipples all there... I think the issue may be the broken wire. FFS. will fit the new sensor anyway but it's fekkin irritating.
 
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mynheers_a_pint

Guest
ok, so just to clarify, there is 1 wire that goes to the det sensor? And which of the two spades should I connect it to?

Ta.
 
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mynheers_a_pint

Guest
right... so new sensor is fitted and wired correctly and the fault code has cleared. BUT much bigger problem now- for some reason now, it feels utterly horrendous when coming onto boost with absolutely no performace what so ever and I'm at a loss as to the cause. I've tried resetting the ECU to no avail. Can anyone help?

EDIT# actually, i saw wired correctly but I'm not sure. We used a multi meter to test the resistance and selected the one that gave a reading of something like 500 ohms while the other was much lower... can someone confirm if this is correct?
 
Last edited by a moderator:
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danr

Member
make sure the connectors are fitting on the spades properly and tight. i think someone else bought one and they werent connecting right. Osmax90 on ngtir
 
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