What injector do I buy?

anthonytsi · Post by **anthonytsi** » 08 Jul 2019, 16:35

I have a 1996 Volvo 850 Turbo Platinum wagon, engine code B5234t. When I go to FCP Euro I have two choices for injectors. One that is for vehicles with a fuel return line and one without. The ones on my car look like the fatter of the two and it is for non-return line cars. However, I do have a fuel line into the rail and one that comes off of the regulator and runs parallel to the other line. I am confused. Please help.

tardcart · Post by **tardcart** » 08 Jul 2019, 17:00

all the turbos are the same. return line off the pressure damper. why are you getting new ones?

Post by **erikv11** » 08 Jul 2019, 17:15

Don't worry about return or non-return fuel line setups, that is not going to matter at all here.

The fat ones (https://www.fcpeuro.com/products/volvo- ... -852-12142) are near-exact replacement for the orange injectors that came with your car originally.

The skinny ones (https://www.fcpeuro.com/products/volvo- ... -852-12163) originally shipped with 1997-98 LPT engines, they are called red injectors. The reds are the same flow rate cc/min as the orange ones so presumably they will work just fine in your HPT. I've never used them in a HPT engine but likely someone has, though I recently asked about that and no one volunteered that they have used them.

How many are you buying, a full set or just a replacement? Another great option is to get yours cleaned, flow tested and rebuilt by a service, will run you about $100 for the set and I would have 100% confidence in that route. If you just want a couple used orange injectors I'd recommend the junkyard or I can send you some for a few bucks each.

anthonytsi · Post by **anthonytsi** » 09 Jul 2019, 16:04

tardcart wrote: 08 Jul 2019, 17:00 all the turbos are the same. return line off the pressure damper. why are you getting new ones?

Misfire on cylinder 4 before and after a tune-up.

anthonytsi · Post by **anthonytsi** » 09 Jul 2019, 16:05

erikv11 wrote: 08 Jul 2019, 17:15 Don't worry about return or non-return fuel line setups, that is not going to matter at all here.

The fat ones (https://www.fcpeuro.com/products/volvo- ... -852-12142) are near-exact replacement for the orange injectors that came with your car originally.

The skinny ones (https://www.fcpeuro.com/products/volvo- ... -852-12163) originally shipped with 1997-98 LPT engines, they are called red injectors. The reds are the same flow rate cc/min as the orange ones so presumably they will work just fine in your HPT. I've never used them in a HPT engine but likely someone has, though I recently asked about that and no one volunteered that they have used them.

How many are you buying, a full set or just a replacement? Another great option is to get yours cleaned, flow tested and rebuilt by a service, will run you about $100 for the set and I would have 100% confidence in that route. If you just want a couple used orange injectors I'd recommend the junkyard or I can send you some for a few bucks each.

Thanks for the advice and the offer.

tardcart · Post by **tardcart** » 09 Jul 2019, 18:38

Its rarely the injector. You could swap it to another cylinder and see if the code changes to that. Volvo uses a inexact batch fire that
sort of equalizes out in the plenum to produce 14% fuel to air. check the routing and pinching and age of the HT wires including the coil.
if you are dead set on a new one just buy one the same color.

Post by **erikv11** » 09 Jul 2019, 19:54

tardcart wrote: 09 Jul 2019, 18:38 ... Volvo uses a inexact batch fire that sort of equalizes out in the plenum to produce 14% fuel to air. ...

I'll have to remember to call on your for backup the next time I am trying to explain to some (or is it only one?) of our most prominent MVS members that (1) batch fuel injection is a real thing and (2) it is what the Motronic 4.3 and 4.4 engine management systems use.

Post by **abscate** » 10 Jul 2019, 06:48

My ME7 reports two injector durations but my sharp eyes have noticed they are identical in length and track each other exactly

I’ve assumed ME7 fires a single pulse length to all 5 - is that the understanding here on earlier systems too?

Post by **erikv11** » 10 Jul 2019, 07:51

That is my understanding, yes.