new here and have a question

[Reelm n Rubi]

You may be able to mix and match parts to make the cam fit, but if it is not a cam made for fuel injection it will run extremely rich and mess with the ECU. I just went through this with my sons 93 Cherokee. The valve timing is way differant. Fuel injected lobe angles run at 107 ish while carbed 258's were into the 110 to 114 area. My sons 4.0 ran, but it fouled the plugs so fast and wreaked of fuel. I just recently called comp cams to get a cam for a 2003 and they flat out said they don't make one but can regrind a stocker for more lift. My reground cam runs .418 lift at 244/248 duration at .006, 196/200 at .050 . with 107 degree lobe seperation. Int opens .050 -9 btdc and closes 25 abdc . Exh opens at 27 bbdc and closes -7 atdc. You can compare those numbers to the 258 cam specs, maybe I'm wrong. I just know it didn't work for my sons 4.0. good luck.

[SilverXJ]

You either needed an adjustable map sensor or you had some other problem. I have ran both the 68-231-4 and the 68-232-4 on my 2000 as have other people and haven't had a problem with either cam. Most every one on this forum with an after market cam has fuel injection.

Of course comp cam is going to say they don't make a cam for x engine if it requires some sort of modification to work.

[Reelm n Rubi]

Wow. Why did Comp tell me differant? Do You think they just don't want to deal with the tuning issues that might come with using those cams. My son's Cherokee definately didn't like the cam we put in it.

[SilverXJ]

The more radical cams would probably cause havoc with the fuel injection system. I really don't know why they would say that it would cause problems for the milder cams. Perhaps low vacuum on some of them? Maybe they aren't tested on FI engines. I don't know if the 258 had fuel unjection or not, maybe thath as somethign to do with it.

Which cam in particular did you put in your son's Jeep? Did you reset the PCM after installation? I assume it is an other wise stock engine? Did you index the distributor correctly?

[Reelm n Rubi]

68-231-4 was the cam We installed. .462 .485 lift on 111 seperation. Vacuum was pretty low at around 14. We indexed the distributer multiple times trying to dial it in perfect. Finally we took it to my local auto guru's shop and even they couldn't get the thing to run right. This could be a combo of issues, who knows. All I know is we put a stock shaft back in last night and will have it running today. If this cam runs bad Then we'll have to figure out which sensors are bad.

[SilverXJ]

Thats the cam I have ran. No problems with it for me. And the OBD II is less forgiving. Perhaps you needed to cut the ears off the distributor to get it indexed correctly? Se here: http://www.angelfire.com/my/fan/dist_index.html

[Reelm n Rubi]

We fired up the 4.0 in the Cherokee with the stock replacement cam last night and it runs perfect. Maybe he just has a tempermental ECU.