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OSUAV8R 03-12-2008 08:53 PM

MOPAR MPFI kit question
I was wondering why you are told to use 92 octane when you install the Mopar kit.
Anyone know why?


OSUAV8R 03-13-2008 03:30 PM

nobody as installed the kit?
Nobody has installed the Mopar kit?

Please.. any help would be great

gas is to expensive to be using a higher grade if it is not required


Fourtrail 03-13-2008 09:11 PM

Most likely because of the timing advance w/ the mopar computer. Keeps motor from pinging. Same thing if you run a high performance computer.

OSUAV8R 03-14-2008 04:24 PM

So your saying I really do need the high octane fuel? Even though the engine is not a high compression engine

roundlitefan 03-14-2008 05:30 PM

Well, just from this married guy's point of view, if I could afford to be putting a Matkins frame under my Jeep, and a $3000 MPFI system on it, the last thing I would be worried about is 92 octane gas.

I would pay that extra $.20/gal ($3/tank:eek:) and drive away from the pump with a big fat grin on my face.

Just my $.02

HighCountry 03-15-2008 08:31 AM

I have always subscribed to Roundlite's point of view! More so now than ever, the percentage more per tank with $3.20 fuel versus $3.45 is tiny. $3.75 on a 15 gallon fill up that is costing $50.00 is too insignificant to worry with...


OSUAV8R 03-15-2008 07:42 PM

Roundlite. When I bought the Mopar kit it was $1600 and the frame cost a lot less then a new jeep. Trust me, I am not doing the frame swap for fun...although I hope it will be

and second. $3.75 per tank over the course of a year is not an insignificant amount of money :)

OSUAV8R 03-27-2008 09:03 PM

Does anyone here have the mopar kit, or is it just me?

tsjeepcj 03-27-2008 09:37 PM

i've got the mopar kit and run premium in it. i bought it used from a buddy, and when we swapped it in complete with his motor, i had to run the rest of a tank of 87 through it. it didn't like it very much. sorry i can't help as to why it needs 93...the manual only says to run 93 if you get spark knock...btw, i love the mopar kit. it starts every time, runs good, and does great offroad....

73jeep 03-27-2008 11:15 PM

Try 87 and if it doesn't ping your fine, if it does retard the timing a little till it doesn't anymore, if you want to run 87 so much. Im guessing there is no knock sensor on this setup.

CompGuru 03-28-2008 01:41 AM

I have an 1983 CJ7 with the 258 and I run 91. I found that the additional MPG overcomes the measly 0.20 cost difference. Also helps with highway speeds. Im sure it's different for everyone's Jeeps. I believe that Mr. Romain runs premium as well. As for the MOPAR kit I don't have one and I personnaly think that $2500 is highway robbery. For that much you could put in a better, newer engine or just do a 4.0L swap and get the same effect.


Rob55 03-28-2008 06:44 PM

I have the MPI kit and like it a lot. I have run 89 in it and it did ok, but it prefers the 91/92 available here (CA). You can play with the timing a bit to smooth it out for lower octane but the performance suffers., but I have just gone with running the 91/92 all the time. The MPI kit is a little expensive but you don't see a lot of posts asking for help with it like the carb and TPI solutions (both of which work great if you know what you are doing for maint and install). I have run it at sea level one day and at 7000 ft the next, no problems.

OSUAV8R 05-16-2008 08:36 AM

Thanks, I run 89 and it seems fine, I just want to make sure I am not causing long term damage

sed437 05-16-2008 06:04 PM

I don't know why, but I put the kit on my 85 CJ7 and use the cheapest 87 octane I can find and it runs great.

OSUAV8R 05-18-2008 10:10 AM

thanks, I use 89 and it seems very happy, I just wondered why they say 93.. there is no point in using a higher octane unless for a real reason..

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