project88mj Posted December 5, 2008 Share Posted December 5, 2008 has any one done this to their jeep comanche i would like to know why this is suspose to be a performace mod? i know that the injectors of a ford mustang 4.6 will fit but they run about $300-$350 what is the cost of ho injectors? would used ones work fine? Link to comment Share on other sites More sharing options...
BLHTAZ Posted December 5, 2008 Share Posted December 5, 2008 The injectors are the same for 1987 - 1995, so no...changing them will make no difference. The injectors for the newer HO's ('97 & up) are completely different and won't work. This has been posted on here probably 100 times or more, but here ya go... http://www.precisionautoinjectors.com/p ... roductId=7 Make your purchase and then be sure to use the word ' JEEP ' in the discount/coupon code to receive 10% off of your purchase. :thumbsup: Link to comment Share on other sites More sharing options...
Motion Offroad Posted December 5, 2008 Share Posted December 5, 2008 The injectors are the same for 1987 - 1995, so no...changing them will make no difference. The injectors for the newer HO's ('97 & up) are completely different and won't work. Actually they are different... the static flow is different among the Renix/HO motors. It is a worthy swap to swap in a set of HO injectors on the Renix motor IMHO. Model Year Part Number Color Fuel Pressure Static Flow 1987-1990 53003956 Black 39psi 18.6lb/hr 1991-1993 33007127 Brown 39psi 21.0lb/hr 1994-1995 53030343 Tan 39psi 21.0lb/hr 1996-1999 53030778 Grey 49psi 23.2lb/hr 1999-2006 04854181 Blue Tip 49psi 22.5lb/hr The injector flow rate varies as the square root of the pressure drop across the injector. The stock '91-'95 4.0 injectors are rated at 22lb/hr @ 43psi fuel pressure, so at 39psi they flow ( sq. rt.(39/43) x 22.0 = 21.0 ). Link to comment Share on other sites More sharing options...
BLHTAZ Posted December 5, 2008 Share Posted December 5, 2008 But still...why change the stock injectors for other stock injectors that are going to make very little difference according to those numbers. The Ford injectors are much better and will make a significant difference for less money and the same injector works for '87 - '95 :cheers: . Link to comment Share on other sites More sharing options...
Motion Offroad Posted December 5, 2008 Share Posted December 5, 2008 Well it really depends on what Ford Motorsport injectors you use. Neither of them are THAT much better... The only major benefit is the pintel design on the Ford injectors vs. the Chrysler one's. Not saying that the Ford one's are a bad upgrade, you just have to be careful on the Renix motor's of dumping to much fuel in. Ford Motorsport 19.0lb/hr @ 39psi (Part no. FMS-M9593-C302) Ford Motorsport 24.0lb/hr @ 39psi (Part no. FMS-M9593-A302) Link to comment Share on other sites More sharing options...
BREEZE1 Posted December 5, 2008 Share Posted December 5, 2008 http://www.lunghd.com/Tech_Articles/Fue ... grades.htm ford injectors have a better spray pattern :banana: Link to comment Share on other sites More sharing options...
BLHTAZ Posted December 5, 2008 Share Posted December 5, 2008 Well it really depends on what Ford Motorsport injectors you use. Neither of them are THAT much better... The only major benefit is the pintel design on the Ford injectors vs. the Chrysler one's. Not saying that the Ford one's are a bad upgrade, you just have to be careful on the Renix motor's of dumping to much fuel in. Ford Motorsport 19.0lb/hr @ 39psi (Part no. FMS-M9593-C302) Ford Motorsport 24.0lb/hr @ 39psi (Part no. FMS-M9593-A302) :agree: The 19lb Design II injectors are the ones that work well in the '87 - '95 4.0L engines...whcih is what I linked to. The 24lb injectors are for strokers. The 4 hole design of the Design II is what makes is do much more effective. My MPG increased by about 14% in the MJ when I used them and by about 8% in my '95 YJ when I installed the same ones in it. Link to comment Share on other sites More sharing options...
SoloCamo Posted December 5, 2008 Share Posted December 5, 2008 Any noticeable power increase? Link to comment Share on other sites More sharing options...
BLHTAZ Posted December 5, 2008 Share Posted December 5, 2008 Not really "power" per-say, but it did make a difference in acceleration & idle smoothness as well as the afore mentioned MPG gains. I am sure there is some gain, but something like this is going to be minimal improvement on HP...5-6 maybe, but just a guess. ;) Link to comment Share on other sites More sharing options...
Pete M Posted December 5, 2008 Share Posted December 5, 2008 I don't really have anything to add to this photo, but here it is regardless. :thumbsup: Link to comment Share on other sites More sharing options...
project88mj Posted December 5, 2008 Author Share Posted December 5, 2008 would used ones be a waste of money Link to comment Share on other sites More sharing options...
BLHTAZ Posted December 5, 2008 Share Posted December 5, 2008 would used ones be a waste of moneyABSOLUTELY!!You will just be getting another set of injectors that are dirty and restricted like what you have already. I tried the used injector thing in the MJ before I found Precision Auto Injectors and they did nothing. Link to comment Share on other sites More sharing options...
project88mj Posted December 5, 2008 Author Share Posted December 5, 2008 good to know Link to comment Share on other sites More sharing options...
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