Hi all,

I bought a new set of Bosch dark green 803 injectors for my dads Christmas present (to suit a 4x4 saph') but these give a misfire at 4000rpm at 14psi

After swapping over each injector with used ones, i'm sure that all 4 new ones are defective by similar amounts, these were removed from a sealed packet by me, not left exposed.

This brand new set are all exactly 4.5ohms resistance.

I have one used set all exactly 4.8ohms that have worked perfectly for 35,000 miles on a 2wd saph' and work perfectly on the above 4x4.

Can anyone please tell me if the differance in resistance would change the fuelling?

If so, can someone please (the more the merrier) measure theirs and tell me what their EXACT resistance is.


Basically, the person i bought them from will not (as yet) exchange the injectors under any circumstance
Also, i have a mate in Norway that bought 8 from same supplier, so want to make sure his are ok too (he's checking the resistance of his now).


Please help,

Cheers, Stu

 

Stu,
The difference in resistance will have no effect on the fuel delivery.
Presumably the ECU chip is mapped to work correctly with the 803s' higher flow rate, and being used with the correct MAP sensor? (ie. assuming you haven't just changed the standard injectors for 803's)?

 

I also remember reading an article a while ago that mentioned it was best to get even new injectors spray tested.......

might be worth considering.

 

Ooops, oh yes good point RichM.........

............presumably the ECU chip is mapped to work correctly with the 803s' higher flow rate, and being used with the correct MAP sensor? (ie. assuming you haven't just changed the standard injectors for 803's)?

 

Cheers for the replies

Yes the chip and map sensor were tested seperately to eliminate them.


Some more info':


The car was originally on std injectors, map sensor, ecu board but with stg1 chip and was perfect.

A new 3bar map sensor, chip/board and greens were then fitted which gave a misfire.

All new parts removed and put back to standard, tested, all OK.

Put all new stg3 kit back in and tested, misfire.

Swapped new injectors and map sensor for a used set of greens and used map sensor, perfect.

Swapped used map sensor for new, perfect.

Swapped used injectors for new, misfire.

Swapped over injectors and tested each new injector individually, misfired every time but at a higher rpm when using 3 used and any one of the new injectors.


It seemed a pretty logical way to eliminate everything else, i'm convinced all 4 NEW 803's are naf!


Anything else i could check please?


I'll be back on the phone to Bosch tomorrow, they've been very helpful but can't replace them, i can get them spray tested but if the supplier won't replace or refund them then i will be paying out more money for no benefit.

 

suerly if you get em tested and they are faulty they would have to replace em,trading standards and all that,you buy a colour tv and it only shows black and white then they sort it or what

 

Hmmm.
Im presuming youve tried em at 23psi as well...?

Id expect a normal greens chip to missfire a tad at 14psi held to be honest due to being on the upper load site and having a rich missfire....

The old clogged ones may be holding her off on the fuelling slightly enough to not miss, and no, the impedance isnt causing it.

 

what is the likely hood of 4 brand new injectors being faulty out of interest ?

 

Stu,

Its been run at 21psi, sorry forgot to say that

It was running 14psi on the stg1 chip, i wanted to fit the stg3 kit and do a quick test run at 14psi to prove all the new parts were ok before adjusting the boost.

Its never run once without misfiring with the new injectors fitted and thats at both 14 and 21 psi.

At present the boost is tailing off to 16psi at 6000rpm as no -31 actuator is fitted yet.

I just don't understand why the old ones are perfect and ALL 4 new ones can cause a misfire!

Is the misfire likely to be caused by a lack of fuel or excessive fuel?


Craig,

I've only ever heard of one green injector causing a misfire and that was used, then left outside for some time which corroded and gave crap spray pattern.


Righty,

Unfortunately they use to sell 803's and 403's on ebay, they were an internet dealer whom no longer wish to trade (so they say), they don't answer the phone, but i do have their address if it comes to that!

 

Not always good to cut out The Bosch Man to try buy cheaper on E BAY

 

Boschman










I WILL be calling you when Saph is put back together

 

Lesson now learnt

These ones weren't actually bought on ebay (although i would have if they had been), the dealer still isn't picking up the phone let alone entertaining warranty!

I buy and sell alot on ebay and have been very lucky to date, when you buy something thats 100% new, you expect it to work no matter where it comes from!