ajpulley

Did you actually use 743s, or 746s? I used 703s which worked perfectly with my performance computer, header, and 2.5" exhaust.

mickharvey

interesting, not sure. got them from someone on this forum. which i thought would work, but no dice.
yes, i did install the 746's because they were leaking so bad. I wasnt expecting any major changes, just an upgraded design. but with no luck at all, going back to OEM, which are $62/each, not excited about that. ..............

cruiser54

Ask the person you got them from for another set!!!

unidentifiedbomb

OEM is crap.... 746s have been in for 3 years now no issues at all.

67 GMC

The old style injectors are under $50 at Rock Auto. But if you put them in, you'll be sorry in a few years. Remember, they are only single hole and obsolete construction. They will come apart and leak but you may get a long run out of them. Mine were over 25 years old when they started to leak. However, I'm not sure that the remanufactured injectors you would get now are of the same quality as in the 80s.

You'll just have to put up with poor performance.
It's up to you.

ajpulley

At this point in time, I don't remember the flow differences between the 746 and 703 injectors. I thoroughly researched as many numbers as I could find, and after a few trusted opinions, I chose the 703s. It takes reading, and re-reading, the posts in this discussion a few times to understand the flow rates compared to your stock injectors. As stated above, the EV1-style are obsolete and have a history of leaks. The EV6-style is much better at atomizing the fuel spray, and has more precise control of the start/stop of the flow. Your set of injectors may not have been rebuilt incorrectly, or so it would seem. However, I do recall reading in a few posts somewhere that others preferred how the engine ran with the 703s in comparison to the 746s.

67 GMC

From earlier on in this thread, there's a link to a website that shows the following:

0-280-150-703 14.2 149.2 107.4 43.5 3

0-280-150-746 26.35 276.9 199.2 - -

So, 703 shows 149 cc/min and the 746 shows 276 cc/min

DFlintstone

[QUOTE=ajpulley;3443356]At this point in time, I don't remember the flow differences between the 746 and 703 injectors [QUOTE]

In a nutshell, what I gathered is that in closed loop the O2 sensor and MAP can accurately trim the slightly rich 703's just fine with a shorter pulse width. While in open loop, ( for whatever reason), running on the computer defaults, it will run rich since the computer thinks you have a lower flow rate. It happens that MY first 10 minutes each morning is straight down. Being the engine gets no throttle and is very slow to warm up I spend more time in open loop. That and trying to help with the ridiculous mileage I was seeing is why I was happy to try the 746's.

Cykososhull

Haha. Man I fudged up big time and thought I bought the 746's for my 1990 renix, and ended up getting the plug and play

BOSCH 4-HOLE 30LB UPGRADE FUEL INJECTORS 88-98 JEEP GRAND CHEROKEE WRANGLER 4.0L.

Nope, boy was I wrong. These are the Bosch 0280155831 Type III 4-Hole EV1 30lb Fuel Injectors. They made my 16.5gpm milage go to 8gpm. It helps to pay attention to detail.

DFlintstone

Yep!

steveitaly

Hi to all, I write from Italy. Excuse for my english.
My xj '90 4.0 renix have a leak problem. How can I show a little clip? I have read this thread, and I suppose that my problem don't come from o ring....
maybe I need new injectors (746?) If are perfectly plug and play....
thanks for reply

cruiser54

Your English is fine. Welcome. 746 is perfect plug and play. A gentleman on this forum sells those injectors rebuilt and with new o-rings.
cummins93 is his user name. He'll likely respond to this thread.
Am I correct in assuming there is fuel leaking right at the injector? We need to determine if the fuel leak is the injector itself or just the o-ring where the injector attaches. If just those o-rings, they will be available local to you.
Up above, just to the right of the paper clip looking thing is what looks like some mountains with the sun over them. Click that to attach photos from your device.

steveitaly

this a screen shot from a video clip.... can I a post a videoclip?

cruiser54

It won't play for me. Appears the leak is up high on the injector. Not uncommon.
If it's the o-rings, they're at the bottom of the injector and you can't see them until the injectors are removed.
The 0 280 155 746 injectors are an upgrade. They are standard on some 5 cylinder Volvos. Hope that helps.

steveitaly

i am waiting for the o ring set. I hope the leack will be resolved. but after i read about the better performances i would like change injector. if after replacing the O rings the leak is not resolved, I will change them by force !!