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1990 Renix Volvo/Bosch 19# 280-155-746 injector swap

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Old 03-15-2013, 12:28 AM
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I deleted this post because I was multiplying, instead of dividing.

Last edited by DFlintstone; 03-17-2013 at 05:55 PM.
Old 03-17-2013, 04:32 PM
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OK. I finally got around to installing the Volvo injectors. I had also purchased new o-rings, filter screens and pintle caps so I stripped the injectors down, soaked them in gas then triggered them with a 9 volt battery and blew thru them with compressed air to make sure I didn't have any stuck ones. All was good so I installed all the new o-rings, etc and stuffed them in there.

Old Flinty dude is SPOT ON! These things make the 4.0 butter smooth. I swear it is quieter as well. Maybe these Volvo-spec injectors don't make as much "clicking" noise as the originals so it is very possible.

It will be a couple weeks until I can report on fuel economy. The XJ is not my DD and the license tabs are expired so I gotta take care of that, then I can drive it on my daily commute for a few days (60 mile round-trip) and see how she does.

While I was digging in to that area, I had not yet replaced the valve cover gasket so I pulled the cover and sprayed it with some wrinkle finish black. No doubt that alone is worth 10HP.

1990 Renix Volvo/Bosch 19# 280-155-746 injector swap-img_0315.jpg
Old 03-17-2013, 05:35 PM
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Originally Posted by Nick-B
OK. I finally got around to installing the Volvo injectors. I had also purchased new o-rings, filter screens and pintle caps so I stripped the injectors down, soaked them in gas then triggered them with a 9 volt battery and blew thru them with compressed air to make sure I didn't have any stuck ones. All was good so I installed all the new o-rings, etc and stuffed them in there.

Old Flinty dude is SPOT ON! These things make the 4.0 butter smooth. I swear it is quieter as well. Maybe these Volvo-spec injectors don't make as much "clicking" noise as the originals so it is very possible.

It will be a couple weeks until I can report on fuel economy. The XJ is not my DD and the license tabs are expired so I gotta take care of that, then I can drive it on my daily commute for a few days (60 mile round-trip) and see how she does.

While I was digging in to that area, I had not yet replaced the valve cover gasket so I pulled the cover and sprayed it with some wrinkle finish black. No doubt that alone is worth 10HP.

Attachment 181439
Red is good for 20 HP.
Attached Thumbnails 1990 Renix Volvo/Bosch 19# 280-155-746 injector swap-stroker-complete.jpg  
Old 03-17-2013, 05:53 PM
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Originally Posted by Nick-B
Old Flinty dude is SPOT ON! These things make the 4.0 butter smooth. I swear it is quieter as well.
Attachment 181439
Too cool! (I tried to do a scientific "double blind" experiment by myself. Of course that's problematic.) Thanks for getting back. I might have seen 1 MPG improvement on two tanks....anyway they are not worse. Working on a 3'rd with the OEM T-stat. I'm looking forward to seeing what they do on a highway trip!

Last edited by DFlintstone; 03-17-2013 at 05:59 PM.
Old 03-18-2013, 05:23 PM
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Originally Posted by cruiser54
Red is good for 20 HP.
U gonna put that in the Rambler?
Old 03-18-2013, 07:26 PM
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Originally Posted by DFlintstone
U gonna put that in the Rambler?
Didn't get the Rambler. Taxes didn't work out that great. Comanche gets it.
Old 03-18-2013, 08:12 PM
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Mine might not be in your price range! The glass, chrome, and lenses might be fine...

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Old 03-19-2013, 02:18 PM
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Hmmm what's the green car in the front...
Old 03-20-2013, 10:53 PM
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72 Vega GT Hatchback. GF melted the engine on my hill at 206K. "the light was on but it was only a mile home" (a mile straight up!)(stupid heater hose blew)


I got 14 AGAIN on the 746's, with the OEM stat on this third tank. The trans side of my TPS is dead. With my added selector switch, and the shifter I'm normally in the correct gear, but it's not ideal for a mileage test. Without a gauge, all I can say on the T-Stat is maybe the defrost temp feels just a tad higher when I get to the bottom of my hill in 8 minutes. (3 miles).

In any case, without an extended highway test, it's "thumbs up" , for the 746's!
Old 03-30-2013, 11:19 AM
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OK, I have good news and bad news after swapping to the Volvo injectors.

Good News: My mileage went from 11.5 to 18 mpg.
Bad News: I don't know how much of that is due to the injectors.

I was a bad boy and didn't really do a proper scientific comparison as there were 3 changes that occurred. Shortly before getting the injectors I had installed a new O2 sensor but I only drove it a little to see what affect that had - overall it didn't run any better with the new O2 sensor but who knows what the mpg might have been. Then the new injectors arrived so I cleaned and installed them and during the process pulled the IAT sensor to check it and it was totally crusted over with gunk so I cleaned it off.

I will say that these #746 injectors do make the 4.0 run smooooooth and between that and having a gas gauge that doesn't move so quickly the XJ is much more pleasurable to drive.
Old 03-30-2013, 01:31 PM
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My '90 xj has an injector that started leaking a few days ago, it's the fourth one to leak, so I'm thinking about upgrading to new injectors. I wanted to go with 703s but these 746s are looking like they might be the better way to go. With the 746s would I need a new fpr and do I use o-rings for the jeep or for a volvo?
Old 03-30-2013, 01:39 PM
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Originally Posted by Illuminator
My '90 xj has an injector that started leaking a few days ago, it's the fourth one to leak, so I'm thinking about upgrading to new injectors. I wanted to go with 703s but these 746s are looking like they might be the better way to go. With the 746s would I need a new fpr and do I use o-rings for the jeep or for a volvo?
No change to any other parts - fpr, clips, nothing. Plug & Play.

O-rings & caps are for EV6 injectors. Not specific to any brand vehicle. Go back to early posts on Page 1, links to o-ring kit is there.
Old 03-30-2013, 01:48 PM
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I'm assuming they fit an 89 4.0 ?

I'm about to press the "buy it now" button.
Old 03-30-2013, 02:38 PM
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Originally Posted by Nick-B

No change to any other parts - fpr, clips, nothing. Plug & Play.

O-rings & caps are for EV6 injectors. Not specific to any brand vehicle. Go back to early posts on Page 1, links to o-ring kit is there.
Thanks for the info, I'm gonna try these on mine.
Old 03-30-2013, 02:40 PM
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Originally Posted by randall L
I'm assuming they fit an 89 4.0 ?

I'm about to press the "buy it now" button.
I think if they'll work on my '90, they'll work on your '89.


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