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-   -   My goal is to get 25+ mpg from my 99 XJ with 30 x 9.5 R15 ATs (https://www.jeepforum.com/forum/f11/my-goal-get-25-mpg-my-99-xj-30-x-9-5-r15-ats-1551782/)

42MBGPW 07-27-2019 12:55 PM

Above 35 mph what do we need power steering for ?

Old school Mopar York RV2 AC compressors had the same shaft taper as the the old school Mopar power steering pump. Back in the day more than a couple guys hung an AC clutch on an extra power steering pump and used that to provide hydraulic power for the snow plows on their pick up trucks.

I see no disadvantages to taking the Cherokees power steering pump out of play above 35 mph. That would be several hp worth of parasitic load reduced for a couple weekends worth of puttering around the shop.

Taylor95 07-28-2019 09:18 AM

I don't think you'll get a lot from removing the ps pump.
The best thing you can do is buy a scangauge on your 96 or 97+ jeep. It shows you real time fuel usage. That was good for maybe 2 mpg above what I was getting before.
I get 21-22 mpg from my normal driving. Just highway gets me 23-24 mpg.

42MBGPW 09-30-2019 03:04 AM

I wasn't talking about removing. I was talking about a power steering pump clutch to deactivate the pump above town speeds. It takes between 5 and 8 horsepower to operate the average power steering system. Reducing parasitic power consumption can't be a bad thing.

Taylor95 09-30-2019 08:09 PM

That sounds like a good idea. If you do mostly highway driving I get it would boost your average mpg by about 5%.

42MBGPW 10-15-2019 12:09 AM

95 Cherokee Sport 4.0, 5sp, 2WD, P/S, P/B, A/C.

Battery replaced. Rear wheel cylinders replaced. Wiper blades and one headlight replaced. Water pump replaced. Cooling system flushed. Idler pulley replaced. Fluids changed. Engine oil synthetic 10w30. Trans oil Castrol synthetic MTF. Synthetic rear diff oil.
New distributor, rotor, brass contact cap, wires and copper plugs and four cans of Seafoam on hand ready and waiting for install on the next available weekend. Fan clutch is bad. Will likely throw a used one on in order to buy time until full electric fans can be done.
Next parts order: NO-OX-ID, materials to custom make 2/0 ga battery and ground cables, NTK O2 sensor, hot coil, fatty wires and iridium plugs. Have found a decent source for 12 hole Bosch 0280156161 injectors. Shopping around for an exhaust shop that can fab a high quality no dent down pipe.

Considering an "economy" aka "RV grind" aka torquer cam at some point primarily because I bought the XJ for general purpose use, parts hauling and towing.

Averaged 13MPG on the half tank of gas that was in the tank when we drove it home. Not surprised since it needs a tune up very badly and the fan clutch is dragging and the gas was of unknown age. Dumped in a whole can of Seafoam and tanked up with fresh 87 octane E-10.

Firedrive 10-17-2019 06:39 PM

It took two weeks, but I’ve now read this entire thread.
Thanks to the OP for keeping it updated and going for so long.

Taylor95 10-18-2019 08:55 AM

Quote:

Originally Posted by 42MBGPW (Post 40767161)
95 Cherokee Sport 4.0, 5sp, 2WD, P/S, P/B, A/C.

Battery replaced. Rear wheel cylinders replaced. Wiper blades and one headlight replaced. Water pump replaced. Cooling system flushed. Idler pulley replaced. Fluids changed. Engine oil synthetic 10w30. Trans oil Castrol synthetic MTF. Synthetic rear diff oil.
New distributor, rotor, brass contact cap, wires and copper plugs and four cans of Seafoam on hand ready and waiting for install on the next available weekend. Fan clutch is bad. Will likely throw a used one on in order to buy time until full electric fans can be done.
Next parts order: NO-OX-ID, materials to custom make 2/0 ga battery and ground cables, NTK O2 sensor, hot coil, fatty wires and iridium plugs. Have found a decent source for 12 hole Bosch 0280156161 injectors. Shopping around for an exhaust shop that can fab a high quality no dent down pipe.

Considering an "economy" aka "RV grind" aka torquer cam at some point primarily because I bought the XJ for general purpose use, parts hauling and towing.

Averaged 13MPG on the half tank of gas that was in the tank when we drove it home. Not surprised since it needs a tune up very badly and the fan clutch is dragging and the gas was of unknown age. Dumped in a whole can of Seafoam and tanked up with fresh 87 octane E-10.

Well, you definitely have some room for improvement! Good luck! I was able to get about 21 mpg consistently over the summer, so I'm sure you could do even better with your 4x2. Additional things I have done are hood vents, a 62 mm throttle body, and a mild performance catback exhaust. Let us know how the 12 hole injectors work and where you got them. I currently have the neon injectors, and they work great. I might swap to 12 hole ones though if they are good.

Quote:

Originally Posted by Firedrive (Post 40770029)
It took two weeks, but I’ve now read this entire thread.
Thanks to the OP for keeping it updated and going for so long.

That is impressive. You would have got a lot of good information from reading all of that. What kind of jeep do you have?

42MBGPW 10-18-2019 05:04 PM

Quote:

Originally Posted by Firedrive (Post 40770029)
It took two weeks, but I’ve now read this entire thread.
Thanks to the OP for keeping it updated and going for so long.

You did better and faster than I did.


Quote:

Originally Posted by Taylor95 (Post 40770403)
Well, you definitely have some room for improvement! Good luck! I was able to get about 21 mpg consistently over the summer, so I'm sure you could do even better with your 4x2. Additional things I have done are hood vents, a 62 mm throttle body, and a mild performance catback exhaust. Let us know how the 12 hole injectors work and where you got them. I currently have the neon injectors, and they work great. I might swap to 12 hole ones though if they are good.

A guess and only a guess is the first mileage check was low due to the ECU having reverted to default map values due to the XJ sitting for several months with a stone dead battery while the later mileage check were greatly and successively improved due to the ECU adapting the map.

I had to run it this last couple of days. A mix of city grid lock crawl and freeway shenanigans at 60 to 72 mph with some hill climbs thrown in for good measure and the occasional WOT to slice/jump/merge or dodge kamikaze drivers. Average gas mileage over 490 miles traveled was 21 mpg. No doubt it will improve with installation of the new new distributor, tune up parts, cleaning up the grounds and a front end alignment.

The results of my best of my research on 12 hole injectors is Bosch Pn# 028015616 / Interchange Part Number 822-11170 is what we're after. Apparently Ford used these in the 2.0 and 2.3 liter Focus from 2003 to 2007 and in V-8 engines in other years. As always verify before going to the parts store or wrecking yard.

They do take EV6 style injector wiring harness connectors so either EV1 to EV6 adapters will be required or the existing EV1 connectors will need to be replaced with EV6 for use in our 4.0 engines.

Taylor95 10-19-2019 09:02 PM

Quote:

Originally Posted by 42MBGPW (Post 40770789)
A guess and only a guess is the first mileage check was low due to the ECU having reverted to default map values due to the XJ sitting for several months with a stone dead battery while the later mileage check were greatly and successively improved due to the ECU adapting the map.

I had to run it this last couple of days. A mix of city grid lock crawl and freeway shenanigans at 60 to 72 mph with some hill climbs thrown in for good measure and the occasional WOT to slice/jump/merge or dodge kamikaze drivers. Average gas mileage over 490 miles traveled was 21 mpg. No doubt it will improve with installation of the new new distributor, tune up parts, cleaning up the grounds and a front end alignment.

The results of my best of my research on 12 hole injectors is Bosch Pn# 028015616 / Interchange Part Number 822-11170 is what we're after. Apparently Ford used these in the 2.0 and 2.3 liter Focus from 2003 to 2007 and in V-8 engines in other years. As always verify before going to the parts store or wrecking yard.

They do take EV6 style injector wiring harness connectors so either EV1 to EV6 adapters will be required or the existing EV1 connectors will need to be replaced with EV6 for use in our 4.0 engines.

That is still pretty easy to change the injectors, although I will have to buy the adapters.

21 mpg is good. Seems like it isn't really in that bad of condition. Is the Jeep at stock height?

42MBGPW 10-19-2019 10:58 PM

Quote:

Originally Posted by Taylor95 (Post 40771617)
That is still pretty easy to change the injectors, although I will have to buy the adapters.

21 mpg is good. Seems like it isn't really in that bad of condition. Is the Jeep at stock height?

Except for the Pioneer stereo it's all stock.


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