Topic: Need help with Prob!

[Jeffy]

Het jeffy, where do I take it to recalibrate it? Like a dealer? Would I still need the speedo gear? And if I fluctuate between 35s and 33s what tooth count would y'all recamenened?

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[roksld13]

Cool thanks. Ok so 33" is 41 tooth and 35" is 30 tooth. If I go back and forth between the tire sizes which should I go with?

[Bounty Hunter]

If switching between two tire sizes (I do between onroad use and off), I'd highly recommend this $80 speedo signal interface from Dakota Digital: http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=126/category_id=287/home_id=59/mode=prod/prd126.htm

[sharpxmen]

Cool thanks. Ok so 33" is 41 tooth and 35" is 30 tooth. If I go back and forth between the tire sizes which should I go with?

you mean 39 teeth for 35'' (i'm guessing it was a typo but just in case)

[aka-justin]

Nice find bounty!  I've only seen similar ones for $200+, like Superlifts TruSpeed Speedometer Recalibration device. http://www.quadratec.com/products/16202_000.htm?sgsc=QSHOPGBASE&utm_medium=compshop&utm_source=googlemerchant

[Bounty Hunter]

There's a little more to the calibration on a Dakota Digital unit, but well worth the $80 and the savings over other products on the market.

[chrisfranklin]

Well the big question for starters is will it rev to close to 5 grand in first second and third? if no, start with part 1 if it's a manual get er rollin in first gear then whem it barely rolls stick it in third and floor it, if it does not back fire then the plugs and wires should be ok then it's on to fuel or an exhaust restriction. Thias is the none scientific method, but it gets you pointed in the right direction fairly quick. a fuel supply problem will show mostly in 5 th gear or near the top in 4th it will hold basck at full throttle, but will pick up speed when you ease up on the throttle a little.

Art,  I've long noticed that my engine seems like it falls off a little in 4th, but especially 5th vs. the lower gears.  And It doesn't feel like it's the highway terrain or anything that the engine is fighting.  It literally seems like the engine itself is dialing back slightly.

This was happening before I made the change to the Ford injectors and I am pretty sure the Fords I have are 100%.  I also change the fuel filter at the recommended intervals.    Thinking about what else in the fuel system, if anything, might be causing this. 

[aw12345]

Seems to me a good start would be to make sure that the fuel pressure under full load is up to snuff. Meaning a gauge hooked up so it can be read while driving and then drive it flatout in top gear.  A failing or worn pump that does not quite produce adequate volume of fuel is otherwise not that easy to catch

[neale_rs]

x2  I really don't think adjusting the speedo is going to help much (good to do but not to solve this particualr acceleration problem), mine is off a bit and it doesn't cause any acceleration problems.

[roksld13]

Ok so got my exhuast and everything it good, my next is to go to the fuel managment. I'm going to check into the pressure gauges this weekend.  Thanks for the info on the digital meter, that sounds like the way to go, one question is it moderatly easy to hook up? I've been wanting to go with the ford injectors for a while, I read the write up jeffy did, great deal of info.  Alittle hard to undestand with all the equations, lol. Anyways that's plus my steering to get working right and I'm going to be broke!!

[sharpxmen]

Ok so got my exhuast and everything it good, my next is to go to the fuel managment. I'm going to check into the pressure gauges this weekend.  Thanks for the info on the digital meter, that sounds like the way to go, one question is it moderatly easy to hook up? I've been wanting to go with the ford injectors for a while, I read the write up jeffy did, great deal of info.  Alittle hard to undestand with all the equations, lol. Anyways that's plus my steering to get working right and I'm going to be broke!!

for the equations: what all that means is that the flow and pressure do not vary on a linear basis and in case you use injectors that have a rated flow at a different fuel pressure than yours you will need to calculate the flow to match with the stock injectors (or go a bit higher but i wouldn't recommend more than 5 to 7% flow increase).

Keep in mind that since you have a TJ the Ford 19# injectors will not work on your vehicle, so unless you find something to match the flow do not attempt. That's where the equations come in, but all you need is to find an online flow calculator if you want to take that route - your fuel pressure is 49psi, you will need the flow and pressure for the new injectors to calculate the resulting flow at 49psi as it is on your Jeep.

[chrisfranklin]

Seems to me a good start would be to make sure that the fuel pressure under full load is up to snuff. Meaning a gauge hooked up so it can be read while driving and then drive it flatout in top gear.  A failing or worn pump that does not quite produce adequate volume of fuel is otherwise not that easy to catch

I'll have to look for one of those gauges with a 6ft hose so I can test/drive at the same time.

[aka-justin]

My probably in 5th gear has been getting worse as now I'm driving mine everyday.  I'm going to have to check the cat and the fuel pressure too.  I know the speed sensor plays into it, but now mines acting up at lower speeds as it wasn't before.  Already did (over the last year and half) air cleaner, o2 sensor, plugs, tps sensor, and had a clean smog test, but 1st gear seems to be almost dieing if I accelerate hard during the hot day.  I'll let you know my results.  Good luck.

[roksld13]

What does it feel like when u say "first gear acts up"? Is it like sliping, I know what that would feel like.  The reason I ask is I can tell a diffrence in temp the way my jeep performes

[aka-justin]

If I lightly accelerate, it's ok.  If I try to go a bit faster (drop the clutch and step on it semi fast) its almost like it looses all power and then slowly surges back.