Topic: Introducing myself...

[2xs]

.. Hey, I have had this 2.5L 1990 Wrangler for a few years now, and im contemplating selling it if I cant get more power out of it, Iv'e been commuting in it for about 2 years now with 33's an id like my fifth gear back...

So before I sell my jeep, im taking one final blast at power upgrades.

See, I really like this YJ, and id hate to lose it. I just bought a 83 K5 project and im becoming addicted to its V8, I originally planned to sell the YJ, but finding a good 700r4 is driving me away from the K5, so im thinking if I can erk some power from the Jeep, ill keep it instead.
My other option would be selling both and buying a Jeep with a 4.0 or 4.2 and doing the Chrysler EFI upgrade...

I know we cant muddle with the timing, however after looking through these boards I cant find any actual upgrades to the early (1990) TBI 2.5L engines.
Anyone got a direction they can send me?

Who am I?
Im a ASE master re-certificated Auto technician, GM trained and im a California smog check technician. I live in Santa Rosa, Ca. married with 2 kids, i love off roading and I play World Of Warcraft when Im not paying attention to the above.

[Torch_Ind]

diff gears would help

there is aftermarket efi systems available or you could source used 95 efi parts and build your own.

[chardrc]

there isn't much for the tbi for upgrades... electric fan helps.. and gears will make the most difference... i think someone here replaced the renix ignition with a msd module and reported good results (although his unit may have been messed up before)

[2xs]

diff gears would help

there is aftermarket efi systems available or you could source used 95 efi parts and build your own.

I have seriously thought about 4:56 gears, it came with 4:11s and if i go too high ill run out of gearing. this happened to a guy I used to work with, he put in 5:13s and was redlined in 5th at 60MPH.

I was thinking maybe there was a way to fool the computer into an extra 5* timing, and maybe a cam upgrade.

Hitting pick and pull and pulling PFI from a newer 2.5 out of an XJ could work. Is there a power programmer for a 96+ OBD2 2.5L? or perhaps someone that does custom reflashing like the corvette guys have?

[sharpxmen]

I have seriously thought about 4:56 gears, it came with 4:11s and if i go too high ill run out of gearing. this happened to a guy I used to work with, he put in 5:13s and was redlined in 5th at 60MPH.

I was thinking maybe there was a way to fool the computer into an extra 5* timing, and maybe a cam upgrade.

Hitting pick and pull and pulling PFI from a newer 2.5 out of an XJ could work. Is there a power programmer for a 96+ OBD2 2.5L? or perhaps someone that does custom reflashing like the corvette guys have?

more advance is only required if you don't burn the fuel completely, otherwise you lose power and experience knocking (detonation). You can relocate the Crankshaft position sensor for a couple of degrees extra advance.

[2xs]

more advance is only required if you don't burn the fuel completely, otherwise you lose power and experience knocking (detonation). You can relocate the Crankshaft position sensor for a couple of degrees extra advance.

Advancing the ignition timing gives the air/fuel mixture more burn time, if you advance it to far, you can get a ping, thats why on higher performance engines you need higher octane fuel, to slow down the burn time to compensate for higher timing and higher compression ratios. Advancing the ignition timing does raise NOX (a result of higher combustion chamber temperatures), that pesky greenhouse gas California is testing cars for. You will only lose power when advancing the ignition timing if you advance it too far. a simple 3*advance is not enough to cause any noticeable ping when done with higher octane fuel.

[sharpxmen]

Advancing the ignition timing gives the air/fuel mixture more burn time, if you advance it to far, you can get a ping, thats why on higher performance engines you need higher octane fuel, to slow down the burn time to compensate for higher timing and higher compression ratios. Advancing the ignition timing does raise NOX (a result of higher combustion chamber temperatures), that pesky greenhouse gas California is testing cars for. You will only lose power when advancing the ignition timing if you advance it too far. a simple 3*advance is not enough to cause any noticeable ping when done with higher octane fuel.

ok then...

[Jeffy]

For 2-3* I wouldn't even bother with the cam and adjust it at the CPS.

[2xs]

Yea, I was looking at the Crank sensor, it seems pretty easy to hog out them holes and move it a few degrees.
I already have a flowmaster (lol it sounds kinda ricey).

I do have a hard top, i can remove that and toss on a bacini top.... I know them hard tops are heavy...

[Jeffy]

Removing your tops won't make much difference... I would rather invest on some valuable power boost parts...

Actually, it does make a difference BUT if you drive on highways, you'll see a drop in mileage.  The hardtop weighs in around 200lbs and the doors are around 45-50lbs so your looking at almost 300lbs in lost weight.  Acceleration is going to be a bit faster with the top off and as long as you're not driving over 35MPH much, you won't notice any loss from higher speeds.

Investing?  It won't be a huge change but free is free. 

[Anthracis]

I say sell both and buy a i6 jeep. You really wont have a lot of power with the I4. Don't mean to piss on your parade. Just my $.02

[2xs]

I say sell both and buy a i6 jeep. You really wont have a lot of power with the I4. Don't mean to piss on your parade. Just my $.02

My other option would be an older (pre 75) IH Scout II

[Jeffy]

Scout II's are getting harder to find.  Although you could go with a 1976, but then you already know that, being a Smog Tech.

If you're adventurous you could do an engine swap.  Then you could have a a V8?  Although I think it would probably be best to sell both and buy a 4.0L.  That will save you a lot of time.  You could also swap in a 4.0L but that's if your 90 is in really good shape.

[2xs]

I have also been thinking about a bike, I miss riding, and a GSXR or CBR would be nice to have again. Building another flatfender could be in the works, Im moving and acquiring a bigger garage.
I had a 48CJ2A in my garage for a while, I got it about 75% finished and then got laid off, it had to go.

I have been looking at Scouts, getting one with no drivetrain and putting in a 5.7TBI or Vortec/700R4/NP208 would be easy.

[2xs]

Wel, as soon as I complete my first potential power boosting mod, Ill start a thread in the appropriate section.

Thank you all for your insight into my situation, it looks like the tech section is where this is going, so Ill go there and hope that if I cant make enough power to satisfy my power hungry right foot, then maybe someone else can use the information I end up with for thier own good.

Until then, its time to get my hands dirty. Look for a tech post soon.