3.4 swap into 1985 Jeep Cherokee questions?

[Canyonero]

Mine is also cable driven. 31x10.5 tires were a factory option, but the normal stock size is 235/75. I'm told they'll even clear 33x10.5 at stock height. I came very close to getting 33s.

Pretty sure I'll be lifting it 2-3" this spring with Old Man Emu springs, heavy duty torsion bars and other gear from independent4x.

There is certainly less aftermarket for isuzus than jeeps, but there is enough. These old Troopers are just such damn fine vehicles. Maybe someday you'll decide you want a real frame under your truck and join the Isuzu club.

[cardana24]

What was your original tire size? I have 31" tires on my Trooper, and my speedo is right on. Originals were 235/75.

I'm not sure what came on it but I used to have 235/75's on it. They were the biggest tire you could run with no lift. Not sure what came stock. Do you have an electronic speedo? Mine is cable driven.

[Canyonero]

What was your original tire size? I have 31" tires on my Trooper, and my speedo is right on. Originals were 235/75.

[cardana24]

Yeah, that's pretty bad. Hopefully I'll have my Trooper figured out pretty soon. I have everything for my ECU swap, but I need to spend some time modifying the harness. In the meantime I might be able to get my current problems figured out (O2 and VSS).

I would like to know what my actual mpg is because I know it's not that bad, but I don't want to pay to have my speeometer calibrated. I know when it says I am going 50 I am really going 60.

[Canyonero]

Yeah, that's pretty bad. Hopefully I'll have my Trooper figured out pretty soon. I have everything for my ECU swap, but I need to spend some time modifying the harness. In the meantime I might be able to get my current problems figured out (O2 and VSS).

[cardana24]

Claims 19 city, 28 hwy.

http://autos.msn.com/research/vip/Spec_Glance.aspx?year=1994&make=Chevrolet&model=Camaro

I know people claim 20MPG w/ V6 Troopers. I admit I'm a little hard on the throttle sometimes, but not THAT hard. 3.4L should get near the same as a 2.8L.

I have good power, runs great. It smells rich, but not like eggs. But I also have no cat. I have very vaporous exhaust, white. I'm pretty sure my VSS is not correct for my ECU. And I get a chronic CEL. I need to get a reader for this thing.

Edit: Ok, I just ordered a reader. Been thinking about that for a while.
http://www.amazon.com/exec/obidos/tg...X0DER&v=glance

I just check my mileage at my last fill up even though I know it is not right because of my speedometer being off. I got 11.56 mpg If I remember correct each of my 32" tires weigh over 50 lbs each...hahaha.

[Canyonero]

Claims 19 city, 28 hwy.

http://autos.msn.com/research/vip/Spec_Glance.aspx?year=1994&make=Chevrolet&model=Camaro

I know people claim 20MPG w/ V6 Troopers. I admit I'm a little hard on the throttle sometimes, but not THAT hard. 3.4L should get near the same as a 2.8L.

I have good power, runs great. It smells rich, but not like eggs. But I also have no cat. I have very vaporous exhaust, white. I'm pretty sure my VSS is not correct for my ECU. And I get a chronic CEL. I need to get a reader for this thing.

Edit: Ok, I just ordered a reader. Been thinking about that for a while.

http://www.amazon.com/exec/obidos/tg/detail/-/B000R3SNJU/ref=ord_cart_shr?_encoding=UTF8&m=ATVPDKIKX0DER&v=glance

[bszopi]

Where did you hear that they get upper 20s in a Camaro?!? Even the newer 3x00s get low 20s in city driving.

[cardana24]

Well, I get like 13MPG, and my speedo is accurate... I know I'm running rich.

What other symptoms do you have?

I know these engines get in the upper 20's in a camaro. I know I am not going to get that with my big tires, but I don't think it should by quite that bad.

As for symptoms I think I have listed them. Egg smelling exhaust, lack of power under full throttle, black tail pipe, black smoke when I floor it.

Why is your rig running rich? I am running all the stock sensors so I am a bit confused why I would be running rich, unless an injector is failing.


*also watching the pulse at the tail pipe I could have a slight miss at idle. Coil pack possibly? Maybe my ignition is breaking up.

[Canyonero]

Well, I get like 13MPG, and my speedo is accurate... I know I'm running rich.

What other symptoms do you have?

[cardana24]

You ever figure out what kind of mileage you get in that thing?

Not really. According to Miles/Gallons I am getting about 12-16 mpg. But my speedometer is off by ~10mph at 50 (i.e. when it says 50 I am going 60), so I don't know how much that throws off my odometer reading. Also I am getting ready to post another thread in the general discussion because I think I am possibly running rich because of the poor gas mileage and a few other symptoms.

[Canyonero]

You ever figure out what kind of mileage you get in that thing?

[ssterlingb]

I think I still have the ecm for my engine that came from a 95 5 speed. I had to get one for the 4L60E trans I am using. I'll try to look for it later & make sure I still have it.
Post the # in case and if I can find it, I'll make sure it is correct.

[Canyonero]

I got one from a '92 Lumina for tuning purposes. I'll be swapping to that when the snow eases up and I can take my 4x4 out of commission for a little while. I just ordered a harness from a Lumina too so I wouldn't have to re-wire the whole ECU plug.

[cardana24]

Could you look at the Serv # when you get a chance? I'm also supposedly using a 5-speed Camaro ECM, but I'm starting to doubt that. Wondering if we have the same #. I'm swapping in a new computer soon so it doesn't REALLY matter, just a curiosity. I've been running my engine on this ECU for a year now...

I'll try to remember to do that tonight.

I also have an ecm out of a 91 or 92 5 speed cavilier with the 3.1 engine (Z31 or something, I forget what the model is called), I thinking about using it but I have no idea if I will ever get around to it. That ecm was recomended to me for tuning purposes.