Engine Shuddering On Start Up

[r34gttt]

Hi guys,

Recently during the mornings when I start up my skyline it seems to shudder a little. The oil pressure remains at 0 for a few seconds and rises as soon as the shuddering stops. When I bought the car it didn't have this problem. Also this only happens when the car is first started, subsequent ignitions don't have this problem. Any ideas as to why this occurs??

Thanks in advance.

EDIT: I forgot to add that the car is completely stock, no mods whatsoever.

Edited March 16, 2010 by r34gttt

[Cadavre]

How long does it shudder for? like 1-5 seconds or 30 seconds? I would be looking to see if there are any error codes on the ecu.

[r34gttt]

How long does it shudder for? like 1-5 seconds or 30 seconds? I would be looking to see if there are any error codes on the ecu.

About 3 seconds if that. How would I go about checking the ecu for error codes?

[Cadavre]

A sparkey can connect it to their diagnostic computer, or if you have a search through the forums I am pretty sure you can use the paper clip method on a 34 to check if there are any codes on the ecu.

If it shudders for that long or less its probably nothing to worry too much about, that being said - my 34 GTT does not shudder at all when starting.

[r34gttt]

A sparkey can connect it to their diagnostic computer, or if you have a search through the forums I am pretty sure you can use the paper clip method on a 34 to check if there are any codes on the ecu.

If it shudders for that long or less its probably nothing to worry too much about, that being said - my 34 GTT does not shudder at all when starting.

It's strange. This morning when I went to start it, it didn't shudder at all. Very odd. Maybe it has something to do with the cold weather. I'll have a mechanic look at the ecu in a couple of weeks when I get it serviced.

[Duncan]

are the revs lower than normal when it is "shuddering"

[r34gttt]

are the revs lower than normal when it is "shuddering"

Yep, the revs and oil were both on 0.

[Duncan]

well the good news is oil pressure relates directly to engine revs. so if revs are 0 or even under 300 would expect the oil light to be on.

need to find out why idle is not stable at 800 or whatever it should be - these cars have a beautiful idle when healthy

[CARSICK]

Injectors is one of several possibilities.

[quarkgun]

This also started happening to me recently, and i also suspected it was due to oil. I changed my oil to a 5-30w (was a 10-40) and it happens less, though it does still happen once in a while. I'm wondering if it isn't the oil pump. My car has only done "61000" kms, but maybe it's time to do the 100k service and change the oil pump. Not sure if you can check the health of the oil pump either... the pressure seems to be fine, but like your experiencing, sometimes on startup it will want to stall and the revs drop right down.

It also sounds silly, but it doesn't seem to happen when i hold the key in the 'start' position a fraction of a second longer than i ordinarily would... does that indicate a tired motor?

[r34gttt]

It also sounds silly, but it doesn't seem to happen when i hold the key in the 'start' position a fraction of a second longer than i ordinarily would... does that indicate a tired motor?

I think we may have the same issue. My motor's barely done 55000ks though so it's very odd.