Topic: Help me figure out this random miss!

[czjeeper]

Not sure what's causing it, but at about 1/2 throttle and above, I get a strange miss.
It will miss and then be fine for a few minutes usually, but sometimes it will miss several times in a row before going away.
I have a new cap and rotor, NGK V-power plugs look good, MSD wires, fuel filter is 2 years old, Witch Hunter rebuilt Type III injectors.
I don't have any codes other than 12 and 33.
What am I missing?
The one good thing about OBDII is that it would tell me where to look!

[Jeffy]

What RPM and are you under a load of not?

[sharpxmen]

what injectors are those? (flow, P/N)

[Bounty Hunter]

The random miss in my YJ was a bad CPS (crank position sensor).

[czjeeper]

what injectors are those? (flow, P/N)

They are the yellow FoMoCo injectors.
Not sure of the part number.
I'm pretty sure they are a 19 lb/hr
Here's a pic.

What RPM and are you under a load of not?

Really any RPM, and yes under load.
I cannot recreate the problem, only randomly happens a few times during a drive.
CKPS is fairly new, but admittedly a cheapo (O.E.M. brand from Costless).

[sharpxmen]

They are the yellow FoMoCo injectors.
Not sure of the part number.
I'm pretty sure they are a 19 lb/hr
Here's a pic.


Really any RPM, and yes under load.
I cannot recreate the problem, only randomly happens a few times during a drive.
CKPS is fairly new, but admittedly a cheapo (O.E.M. brand from Costless).

ah, you have a YJ - I thought was a TJ since you mentioned OBDII - that really has nothing to do with the codes but more with the standard, your PCM will report as good as an OBD II except for the cat efficiency. Could be the CPS like bounty said, could also be TPS (but usually throws  a code) and can also be ignition or fuel related. Hard to tell with little info, try to pinpoint the behavior better then it might point to something. Cheapo stuff got me stranded, bought a cheap ignition coil and it completely died after just 1 year (got it brand new), so with those you never know.

[Bounty Hunter]

Ya cheapo sensors and ignition parts are soooo iffy on reliability, really is a crap shoot.

[czjeeper]

Anybody know where I can buy new injector pigtails?
Mine feel like they are a bit loose.
I'll start with that.

[sharpxmen]

Anybody know where I can buy new injector pigtails?
Mine feel like they are a bit loose.
I'll start with that.

i think you can get them off Summit or Jegs. You can also find new ones on eBay but not sure if they're made in China or not, if they are i'd pass and go for the ones made in Europe or US.

[czjeeper]

Got a link?
I found these.
http://osidetiger.com/EV1pigtails.aspx

[Jeffy]

You can buy EV1 connectors as a kit so you don't have to solder.  Looks like the newer ones use a metal clip instead of relying on the plastic.

http://www.google.com/products?q=EV1+connectors

[sharpxmen]

Got a link?
I found these.
http://osidetiger.com/EV1pigtails.aspx

http://www.summitracing.com/parts/PCO-5625PT/
http://www.summitracing.com/parts/SMP-S697/

both look like EV1 but is not specified so i would call them to confirm

I just looked a the link you posted and they're cheaper so probably a better option. If you buy them as pigtails then you'll need to solder and use shrink tubing on top