DFlintstone

At least wait until I finish this tank. Just one fill-up can't give very good numbers, but if it's "significant" there might be a clue there.

There just arent' words...smooth at silk! All I can guess is it lengthened the pulse width it used on the 23# 703's and somehow that burns smoother. Maybe the spray running longer results in a better mix, then the shorter shot/burst it calculated for the 703's.

DFlintstone

OK, (Rooster and Nick), here's the deal. My gauge sticks on 1/4 when I get down near 1/2, then works again when I get below 1/4. Years ago I pulled it, had a friend watch the needle while I moved the float, all OK. Reinstalled, same result. So there's that. It will come down off 1/4 in a week or two and I will fill exactly the same way, parked at the same pump.

Ugly tranny problems today! Rev, slam! at low speed comen' up my hill. Hard jerk then as if in neutral for a sec, than bam! engaged. Been driving like a kid with the new performance. Idk. It's full of pink fluid.

Maybe Thursday I finally check my TPS. Very not good, that rev, bam! I went really easy my last mile up to my place.

I DID "McGiver" some TCU wires which has been great for descending my hill in 2nd gear. Maybe a problem with the switch.

DFlintstone

OK, I'm trying to shorten the thread to focus on the topic. Criiser and I deleted a bunch of discussion about my TPS/TCU. The TPS issue is here, https://www.cherokeeforum.com/f2/90-...-4-0-a-163752/

cruiser54

I'll bet your TPS is dying. Yes, that's what happens.

DFlintstone

Say it ain't so Joe!

cherokeelaredo'90

I used to have high idle issues and when I'd have the tranny in power mode it would stay in get till 3k no matter what gear. It would just hold the gear way too long and not shift even though I was barley giving any throttle. I finally decided to buy a new tps and my high idle and tranny issues are gone. I drive around in power mode all the time now and it shifts smoothly. I'd vote that you need a new tps, just rock auto it. It's like $20 if I remember correctly

DFlintstone

Hey! I topped up at only 191 miles. 13.7 gals gives 13.9 MPG. If that were correct that's a 1 MPG improvement.

It happens to be that right there, a one gallon error ether way is about 1 MPG. Certainly not a "solid" data point, but encouraging!

I'll hit that drum again, it runes SUPPER sweet with the 746's, sweeter than ever!

DFlintstone

OK, these #'s are consistent. I topped up again after another 178 mi, 12.7 Gal, for 14 MPG. Small sample but 13.7 on one tank and 14.04 on the next suggests something. About one more MPG, over the 703's, (about 8%).
If I filled up three times in a month at $50 each, that's a $12 savings.

So I'm gonna say, go ahead, try the Bosch 280 155 746 in your Pre 91, Renix Jeep!

They are "plugn' play" #19Lb/Hr, (16 Ohm), four hole with the clip slot. (Thanks for the tip Programbo!)

Edit 12/16/13 Clearing 15 backing a trailer and going to "beer-mart".(OK, might be less backing the trailer) ( 22 on the highway. I'm always "heavy" if I'm on the highway with tools and gear.

My "Base" was on about 15 fillups. This was only two, to test the 155 746's. I feel pretty solid on the 13 to 14 MPG improvement. Pretty safe bet they are not worse in any case. AND! Soooo supper sweet! (Smooth) Just to be redundantly clear, these numbers are for sort trips on small roads. I was seeing over 18 on the Highway with the 703's. For these 746's I have no data. I should also re-state that I'm over 270,000 mi.

Renix, I did install the Mopar T-Stat just now. I cut my time on a t-stat change from three days to three hrs!

cherokeelaredo'90

Sounds like you're having success with them ever 1mpg improvement counts! Where might you find a set of theses injectors? Or did you order new oe replacements from somewhere?

DFlintstone

The Mopar (OEM) T-stat has the check valve located better/higher, and a larger opening than the (not Stant), that I got from Napa last year.

Sorry of me I don't save the box/info on what it IS. OK, I found stamped on the strut of the faulty stat, "MotoRad"

DFlintstone

Also the new T-stat I've been using for about a year doesn't close all the way. After another dip in hot water it left even more gaps. To late for more photos, you get the pic!

OK, I'm adding a photo and following up. It turns out the "faulty" MotoRad T-stat seemed easy to fix. It turns out simply rotating, seating the spring made it seal properly. The large end of the spring was at a place that would tip the disk that seals. Possibly a mistake off the line? I didn't even look at it before I installed it last year. It doesn't start to open until 195*, and is pretty wide at 200*.

Still the Mopar "opens larger", has a better position for the check valve, and presumably didn't come with a flaw that needs corrected. (I didn't check to see if it was seated cold!)

DFlintstone

I somehow missed your post last night! I bought mine used, "as is" (and ended up flushing a couple sticky ones) >>> http://www.ebay.com/itm/281064226718...84.m1439.l2649

I'm not sure if Programbo has this exact injector, refurbished and ready to go, or not. You might ask him...

87XJLIMITED

I'm gonna run my 703's awhile longer before I try the 746's I got in the mail yesterday, now that my O2 sensor is working correctly. I normally could go about 100-125 miles before the fuel gauge hit 3/4 tank, since the O2 sensor was fixed I have gone 90 miles and I'm not even 1/2 way to the 3/4 mark yet.

DFlintstone

Yea, good deal. My sample of only 2 tanks is small. I should mention though, closer to 12.7 was the "baseline". I didn't mind posting 13, as that included bringing in this winter's wood, lots of messing with the trailer and idling and messing around.

Open or closed loop aside, a warm engine will be more efficient than a cold one. Fuel atomization and combustion, as well as other things like the oil & friction, even the ring end gap , all get better at operating temp.

An over rich-condition won't help it get to temp. Actually fuel evaporation sucks heat out of a system. (that's how my frig, any your AC works).

So in only 8 minutes, going two (gentle), miles up my road, my defroster felt pretty darn warm. Pretty nice 60*+ Day. No Great surprise after seeing the "MotoRad", T-stat was not "coming home" on it's seat. (I might actually tweak it to see if I can "fix" it.) It's trien', just didn't quite nail it.

DFlintstone

BIG mistake here in post #11. Divide!! CC's by 10.5

Hope I didn't mess anyone up.