1990 Renix Volvo/Bosch 19# 280-155-746 injector swap
03-30-2013, 05:30 PM
#46
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Yea, "plug and play" for 87-90 4.0's Come back and let us know what you think!
03-30-2013, 06:19 PM
#47
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Year: 1990
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Engine: 4.0L upgraded charging system & blue top, flowmaster 44, hi flow cat and two core rad.
Originally Posted by DFlintstone
Yea, "plug and play" for 87-90 4.0's Come back and let us know what you think!
03-30-2013, 09:20 PM
#49
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The o2 sensor (and puter), can shorten pulse width so earlier Jeeps can use the slightly higher flow rate 703's. When it's cold, using a "default" pulse width it might run a little rich.
The 746 is a lower flow rate than POST 90 uses. I'm not sure why, the pressure didn't go up till 96 Might be the 746 in a post 90 can't flow enough fuel to be optimum.
Check this out> http://www.jeep4.0performance.4mg.com/tech_specs.html
The 746 is a lower flow rate than POST 90 uses. I'm not sure why, the pressure didn't go up till 96 Might be the 746 in a post 90 can't flow enough fuel to be optimum.
Check this out> http://www.jeep4.0performance.4mg.com/tech_specs.html
Last edited by DFlintstone; 03-30-2013 at 10:18 PM. Reason: 96
03-30-2013, 10:11 PM
#50
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I have the 746's in my 87 and in my opinion it runs a little smoother than the 703's I ran for about a month. Power seems to be the same. I haven't even ran a tank of gas through them yet to test MPG.
03-31-2013, 11:30 AM
#52
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The o2 sensor (and puter), can shorten pulse width so earlier Jeeps can use the slightly higher flow rate 703's. When it's cold, using a "default" pulse width it might run a little rich.
The 746 is a lower flow rate than POST 90 uses. I'm not sure why, the pressure didn't go up till 96 Might be the 746 in a post 90 can't flow enough fuel to be optimum.
Check this out> http://www.jeep4.0performance.4mg.com/tech_specs.html
The 746 is a lower flow rate than POST 90 uses. I'm not sure why, the pressure didn't go up till 96 Might be the 746 in a post 90 can't flow enough fuel to be optimum.
Check this out> http://www.jeep4.0performance.4mg.com/tech_specs.html
04-03-2013, 03:41 PM
#53
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Well...my (4th), tank, tanked. 11.8. I DID do a bit with a very heavy, large trailer, including more than a few miles going slow up and down a steep gravel road and more than a little idling and "inky jinking" the trailer in very tight spots. Almost saw the gauge dropping! Then filled at a different pump. An 'abnormality" I think, since I just had the three consistent 14's , (with nearly no highway). 
04-13-2013, 01:07 PM
#54
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Year: 1990
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Engine: 4.0L upgraded charging system & blue top, flowmaster 44, hi flow cat and two core rad.
I got the 746s installed. My xj runs smoother (not perfect I think something else still isn't quite right), my rpms increase to about 900 and noticeably more power. I filled up my xj after running around some (only about 40 miles were with the injectors) but milage didn't look better about 10mpg. I'm hoping the next tank returns better numbers. Thanks guys for trying these and posting it up, hopefully these will never leak, that's a big upgrade from the stock ones all by itself.
04-15-2013, 03:11 PM
#55
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Any news Illuminator? I guess like yourself Randell had issues both before, and after the swap. Huh? A bomb just killed two at the Boston marathon.
Anyway anyone following, be sure to get the correct number. There IS another (higher flow), that ends in 746 as well.
Anyway anyone following, be sure to get the correct number. There IS another (higher flow), that ends in 746 as well.
04-17-2013, 09:36 PM
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Changed to the 746's and didn't notice much gain of fuel mileage, still around 16-18 in town and highway driving. I modified my CPS to look like the high altitude CPS and on my last tank I got 21.3 MPG. Sure is nice to watch the miles add up and the gauge not move as fast as it use to. I will see what the results of my next tank of fuel are next week.
04-17-2013, 10:10 PM
#57
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Year: 1990
Model: Cherokee (XJ)
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Here's a comparison of a CPS I modified versus the factory high altitude one. I squeezed all I could outta mine.
04-17-2013, 11:25 PM
#58
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Back in the days of points I always custom timed each engine. With the fuel you run, at temp accelerate from 30 to 50 mph, in high gear, and set it so your engine, on that fuel has a"ghost" of a ping. I made lots if friends and got allot of references because I was so keen on running the absolute, maximum, advance your engine could run.
I got a TPS from my very grumpy JY guy today. His studs broke on his forklift...his wheel fell off. Trust me , you don't want to be there! (he likes his forklift). So I gave him $20, $5 more than something new on Ebay.
I'm "all in" with the advanced CPS. The knock sensor should optomise it. If it were to "kick back" to default with a knock signal, then come back, that still seems better than being retarded. (or advanced less than optimum).
I feel pretty solid on the 1 mpg improvement with the 746'6. Three very careful, consistent tanks, against a larger sample on the 703's. Also it's really supper smooth. (that one mpg is only on small, short trips, I rarely do even 3 miles of highway)
Yes! After I get my TPS issues resolved, I myself will be happy to try the advanced CPS as well!
I got a TPS from my very grumpy JY guy today. His studs broke on his forklift...his wheel fell off. Trust me , you don't want to be there! (he likes his forklift). So I gave him $20, $5 more than something new on Ebay.
I'm "all in" with the advanced CPS. The knock sensor should optomise it. If it were to "kick back" to default with a knock signal, then come back, that still seems better than being retarded. (or advanced less than optimum).
I feel pretty solid on the 1 mpg improvement with the 746'6. Three very careful, consistent tanks, against a larger sample on the 703's. Also it's really supper smooth. (that one mpg is only on small, short trips, I rarely do even 3 miles of highway)
Yes! After I get my TPS issues resolved, I myself will be happy to try the advanced CPS as well!
Last edited by DFlintstone; 06-16-2013 at 03:49 AM.
