cardana24

iTrader: (81)

When I go out and start my 95 in the morning the car has a very lumpy/rough idle when I crank the car. It does not try to turn off but it does not idle smoothly. This goes on for about 15 seconds then the idle goes smooth as butter. What would cause this? I was thinking maybe oil? I just changed the oil hoping it would help this problem but it did not. Could it be the oil filter? I am using a Fram currently, do any of the recomended filters actually have a check valve in them that hold the oil up in the motor when you turn it off? This problem is really bothering me, what could it be?

njmodi

iTrader: (4)

Almost all good quality (i.e. not FRAM ) oil filters have anti-drainback valves (ADBV).

I would suspect a dirty idle air control valve. That is what helps maintain/regulate the idle (especially important on a cold start). Try clean out the throttle body and IACV and see if that helps.

Let me clarify something - you state the idle is lumpy when you crank the car, I am assuming you mean the idle is lumpy once the car has first been started right? You don't mean that the cranking itself is lumpy... or do you?

PS: Just order a bunch of OEM filters from Jerry Rome - they have a free shipping special - the OEM filter is >>>>>> FRAM and is only 2 bucks more... it makes no sense to use FRAM.

cardana24

iTrader: (81)

Yeah when I crank the car it cranks easy, but once it catches it runs like crap for about 15 seconds. So does Fram not have the anti drain back valve? And yes I would rather run nissan filters but I was in advanced and I am changing the oil very frequently now, since the car is new to me and I do not know much of the history. Also I cleaned the IACV and TB before I put the car on the road so I do not think it is that. To me it really seems like some sort of lack of oil on start up.

njmodi

iTrader: (4)

The FRAM toughguard and X2 lines do have an ADBV, but it may not be as effective as the one on a better quality filter.

cardana24

iTrader: (81)

I was using the regular fram with the black gripy stuff on the end...not sure the model name. I just went ahead and ordered some filters from JRnissan, I am hoping this is the problem. Any other ideas if this is not the problem?

njmodi

iTrader: (4)

It could be minor fuel starvation from a bad ECTS or pump..
It could be flooded engine from leaky injectors (since you say it only happens on a cold start).

Do you notice any smoke when you first start the car (when cold)? Have someone else start the car next time, and check for smoke.

There are lots of possibilities .... some much less likely than others... I've just stated the first things that come to mind.

jmeister

iTrader: (12)

Just tell people it's cammed.

XeroX

iTrader: (13)

Nice way to contribute

I have heard cleaning the CPS (crank position sensor) may improve starting, and idle during cold starts, i have yet to try this however. I remember there being a few things in a write up that can be "cleaned" to improve these kinda problems relating cold starts. I cant seam to find the info tho...sigh...

Anyone have this info/write-up?

While your down there, might be a good time to re grease your starter also.

cardana24

iTrader: (81)

CPS....thats the one on the side of the bell housing right? I have a brand new starter. I just got the car and so far I have put a water pump in it (paid someone to do it), driver side axle, Intake air temp sensor, after market intake (because the stock one was all broken up), starter, ignition switch, some interior trim stuff, center console, glove box etc.

njmodi

iTrader: (4)

There are 2 Crankshaft position sensors - one on the tranny bell housing and one right under the crank pulley.

The camshaft position sensor also affects timing/startup - and is located in the timing chain cover, right near the idler pulley tensioner.