Topic: Bosch Design III o-rings

[chrisfranklin]

Installed the Bosch IIIs a few months back.  And they have performed well.  Almost from day one though its had a bit of a rough, lumpy idle until the engine has warmed up.  Then it seems to smooth out and generally run better than before the install.

I am beginning to think that there may be a slight leak in one of the injectors -- perhaps an o-ring is causing a problem somewhere 

I stuck with the o-rings that came with injectors and that's what I used for the install.   So I might have gotten burned on that even though the rings looked like they were in fine shape when I put them in. 

I went ahead and picked up some new o-rings and and am going to pull the injectors and reintall them with the new rings.  Given  the lumpy idle business -- nonexistant before the intstall and all else constant -- what would you guys do to attempt a fix?  Pull the injectors?  Replace the o-rings? 

[Jeffy]

That would be the easiest thing to do.  New O-rings are $3.  You might need to replace the caps as well.  I'd at least take them out and inspect them.

[jonzjeepyj]

Jeffy, 
    Sorry to Hijack the thread but I have the same questions.  I'm in the same
boat.  I think I will replace the o-rings for three bucks, before I do my install,
to save me the aggravation down the road.  How much are the caps and do
you have both part numbers (O-rings and Caps).  Also, the best place to get
them.  Dealer / NAPA / or ?....   

Thanks,
John

[Jeffy]

I have a set of Fel Pro Fuel Injection O-Ring Set Part Number: ES70599.  Although I didn't bother replacing the O-rings on the Design III's since they looked good and not torn,tarnished or dry.  I haven't had to replace the caps.  Remember to check BOTH O-rings.  There is one on each end.

[tallrugbyguy]

i have a similar problem.
i thought my injectors were faulty but after some twisting and tinkering the idle smooths out.
i think it had new caps and o rings, but i did it at -20 celcius so i probably tore one. i can see visible fuel leaking.
i guess dealer would be best bet?
im using the design III

i tried napa and they couldent match anything

[Jeffy]

http://www.partsamerica.com.  If you have a Kragen, Schuck's,Checkers or Murry's, you can do in store pickup.  Prices online are many times cheaper then in-store as well.

[oldjeep]

http://www.partsamerica.com.  If you have a Kragen, Schuck's,Checkers or Murry's, you can do in store pickup.  Prices online are many times cheaper then in-store as well.

  And O'Reillys .  Oreillys bought out CSK auto a while back

[chrisfranklin]

I was thinking I had a bad o-ring or something else wrong with the Bosch 3 injectors to cause the rough idle.  Maybe I do or don't have a bad o-ring, but I found something else that seemed to correct the idle business.  Turns out I'd been driving around for a while with the coolant resevoir and to some extent the radiator partially empty. The coolant guage had broken a while back and my attention when it came to cooling was on getting that corrected.

Anyway I topped the resevoir and the radiator off and the idle seemed to return to normal.  Then I recently went and had the Jeep smogged since it was somehow picked by CARB as being a potential high-emitter (DMV wouldn't issue my registration until I did).  But even with the Bosch 3s, it passed (Though I did notice that the HC levels were seriously close to exceeding the CARB limits at 15mph and 25mph).  But hey I can't complain.