[gull sentra]

First off, I don't drive this one much(7,000mi/yr).

I have a COLD START problem, runs rough for a few seconds, then just fine after.(of course the computer says I have misfire)

*I've put in fuel injector cleaner in for the last two tankfulls.
*Run it on the interstate at 70 mph for 30 min or so.

Help please!

 

[i68k]

please dont put harsh cleaners into your vehicle


sounds like you have a bad coilpack, just get yourself a rebuilt kit and see how you make out, assuming youve done tune-up or changed your plugs recently? this could also be the cam sensor or crank sensor, but try fixing your coilpacks first if youre coilpacks are still original. its about $35-40 at a dealerhsip for the four coilpack rebuilt kit, which works as long as the ignitor in your old coilpack is still good. the kit comes with all new pressure springs and capacitors.

EDIT: did your motor lose idle? is your idle bouncing?

 

[gull sentra]

Thank you for responding. I don't have a problem with replacing coils.....but
Hummmmmm! I don't understand, I thought when coils went out they stay out. My car runs fine after a few seconds, with good acceleration.

Engine does not die at idle.

 

[i68k]

there are capacitors in the coilpacks, so sometimes when the capacitor is very cold, it doesnt fire properly until it warms up, so it may miss the first few fires before it kicks back in. this is normally the end-of-life of the coilpack, but like previously stated, they are rebuildable if your ignitor still works. you may only have one coilpack thats failing, and the engine can run on 3 cylinders, although not very well, so it might not die at idle.

 

[gull sentra]

Thank you for Patience with me.
I checked with the dealer, they said there is no rebuild kit, you just replace.

NOTE: the coils sit on top of the spark plug boot and are each(4) bolted down to the cover.

I could replace the whole 4???
I do know a Crank Sensor costs around $25 bucks.

UPDATE:
My learning curve is long, sorry.
Found what the auto supply called a "plug boot", they are the lower part of the Assembly
,containing the springs, etc.
Working on it now.

 

[i68k]

sounds like the dealership is trying to make more money from you, or talked to the wrong person.

here is the link to the 2.5 coilpack rebuild thread. this is the same procedure to rebuild the coilpack, except the part number maybe different for your 1.8! the kit rebuilds 4 coilpacks, and it around $35. im not sure what autopart stores will call this kit, if they even have it, but you do replace the internal pieces of the lower part, which is springs and capacitors. for this to work, your ignitor need sto be working, the top big block of the coilpack where the harness connects. reference:
http://www.b15u.com/sentra-specific...64-fixing-your-coilpack-w-breakdown-pics.html

if you choose to get cam & crank sensors before rebuilding your coilpacks, you should get both cam AND crank position sensors. you should try to get the metal type sensors, which look like a metal cylinder instead of flat plastic sensor.

 

[gull sentra]

Thank you so very much.
I think I* have it. I replaced the plugs** and the boots.
I've done two "cold" starts with no problem. One more cold start and we will call it success.

*Of course I could not have done it without you.
** Plugs had only 22,000 mi on them and looked fine.

The link to the "how too" was nice.

 

[i68k]

glad i could help, the fsm will be your best friend