JeepComanche89

Awesome, thanks again. I thought the markings were different, my mistake

Yes. The 91-95 HO flywheels are the same. Awesome, thanks! I'm assuming I would need to get a CPS for a 91, 5 speed comanche though? As I believe I mentioned before ggcnash's truck is an automatic

I have a AX-15 from a 95 XJ in my comanche now. I am running a flywheel from my 88 with a peugot. Would a flywheel from the 95 XJ, work with the 91 comanche HO cps and computer? what do you guys think?

I'm the buyer of the engine and harness. Yes I know that there are other ways to convert to a HO motor, but I'm only interested in doing the complete harness swap. Before everyone chimes in, I have done all of cruisers tips, and I know its not a real hp gain, I'm just looking to ditch the entire renix setup as I am just not a fan. IMO the HO setup is alot cleaner. That being said I believe I need the engine harness, and the under the dash harness, and PCM. The engine harness should plug into the lower dash harness witch eliminates the connector issue. Also, there's the fuel pump issue. I believe I would need the wires that go to the fuel pump, and a 91 comanche sending unit. (I'm not quite sure if there's anyway around this) ggcnash is including all of the sensors with the engine, so none of that should be an issue. I also have a a 91 gauge cluster. And it should be noted a have an AX-15, so I think I am able to just not use or cut out his automatic transmission wiring completely. So, in review a PCM, engine bay harness and dash harness are definite, a HO comanche specific fuel pump harness and sending unit may also be necessary. Thats my understanding, how does that sound to you guys?

I just checked them out, looks like nice stuff. For now I think I like the clifford option because of the dual outlet. That way I know he can get a pipe to match up to it. However I would actually prefer a single outlet for clearance with the drive shaft. I don't do any crazy wheeling but I have hit my current y pipe on a few occasions. I will probably call him tomorrow and see what he says

That makes sense, to be honest I didnt even think about the angle of the output pipe(s). I'm pretty confident in the exhaust guy I found, and I'm sure he could make the angle work. Right now I have the pacesetter header, which has a y pipe and a intermediate pipe?, that connects the y pipe to the cat. That pipe had a bung in it for the O2, And I relocated it there. I would imagine he could handle the egr bung/tube as well. Pretty sure he would have to fab up a new tube to fit the new header properly. I don't even know if the clifford has any bungs, it has no picture and dosen't mention it in the description.

I emailed him about the 57-2000, and he said it would fit an 89 4.0 perfectly. The description says it fits 87-05 4.0s, which i thought was odd. The guy said that the only thing that changed between the heads was that the intake ports moved upwards in the later years. I'm not sure what to think now

sheeeeetttttt, I remember that website now! I found that back when I was first looking at headers but was too stupid and poor to buy the good one and settled for the pacesetter. Ive learned my lesson lol. Thanks for posting that

but arn't the ports different? I don't really have a problem with the flange, my exhaust dude can take care of that

did they custom make it for you?

Anyone know of a secret place to get renix 4.0 headers? BESIDES pacesetter. Or a place that makes custom ones? thanks

it kind of makes sense, the fact that the cat was pretty new had me doubting that but i really can't think of anything else it could be. I'm going to tell the exhaust dude to check out the cat since he has to redo everything from the cat up. I may just look myself today if i get a chance.

Never heard that. Concerned about a clogged cat? See Tip 16. It seemed kind of odd to me too. The cat is a magnaflow oem replacement i believe. It is coming up on 2 years old this January. I was planning on taking the cat off, and inspecting it, then driving the truck to see if my symptoms improve. But unfortunately yesterday I developed a pretty significant exhaust leak at the manifold gasket. I'm not sure if this was the original cause of my problems, but it definitely got worse yesterday, which was when i first noticed it. In other words I'm not sure if it was leaking a little bit before, and got worse, or just developed in full yesterday. As a recap, I already have a known exhaust leak at the header collectors. I plan on bringing it to an exhaust guy whenever he can fit me in, probably Thursday or Friday. I hope fixing the exhaust for good will also solve my other problems. But I would be pretty devastated if I pay to get the exhaust fixed, and it turns out its within the block. There's no knocking or anything, but i don't know much about engines. Do you think its a possibility that its mechanical and I'm just spinning my gears with these sensors? Not that the rest of the grounds didnt need to be upgraded anyway

So i read a clogged cat can cause high voltage to the o2 sensor. Is that the same for renix engines?

I checked the fuel pressure while removing the vacuum line from the fuel pressure regulator. With hose connected, psi is 30, take hose off and it jumps to 38ish. This should mean the regulator is working then correct?

Any other ideas of what it could be? I'm still experiencing the same problems

Yes I thought i did step 6 already, but apparently I found the wrong crimp connection. As I posted earlier in the thread, I found 6 black wires going to one black wire and soldered and heat shrinked it. Yesterday I found another crimp connection that I believe was the correct one mentioned in step 5 and also eliminated it. So its safe to say step 6 is complete and successful.

So I went to eliminate to c101, and found another crimped connection that I must have missed the last time. 3 brown wire w/ white tracer I think, into 1 brown. Soldered/headshrinked it, and then rechecked the resistance on the tps. This time I was getting .3 ohms resistance, and NO fluctuation when wiggling all parts of the harness. So i left the c101 as is for now, and checked the adjustment on the TPS. It checked out perfect. Still saw no improvement, so I replaced the O2 out of desperation. Still no change. Its pouring right now so I can't really do anything to it, but as soon as I get a chance I will eliminate the c101. Any other thoughts?

Haha awesome, I was think about buying a factory scan tool off ebay. So I will hold out on throwing that in for now, and I will do the C101 elimination. Any place to buy a nice grommet for the firewall?

Should I replace the O2, or wait until i do #27?

I have cleaned the connector well about two months ago. I was planning on eliminating it but things keep getting in the way. But I will try to get it done sometime this week.

Ok, I thought so, just wanted to make sure there was no secret place to buy it lol I just feel that the head provides a better ground than through the heat sheild then manifold bolts. But I trust you lol And to recap, I am getting .8 ohms resistance in terminal B of the tps. When I wiggle the harness, It jumps up to 1.1 ohms. Currently I have a bosh O2 sensor installed. I put that in a year and a half ago when I put the truck on the road. I thought the cause of my problems may be the O2 and bought another new bosh sensor but have not installed it yet. Sorry I know its alot of info, but I appreciate everyones help

That hose was previously broken and had 2 "couplings", but it didnt leak. But today i actualy did break it lol. I repaired it with another line i had laying around, and ended up cleaning the throttle body in the process. Where can I buy a new vaccum line? Also when i was working on that, I noticed the grommet in the throttle body has 2 openings. The line to the MAF sensor is on the bottom, but the top opening has no line, there is an open hole. What is meant to go there? Today I also replaced the braided ground cable per your recommendations, and bolted the one end to the heat shield on the manifold. I'm not sure why thats better than the head but that is what you recommended so i did it. I also made a ground from the negative post to the radiator support like you suggested. the second thing I did was check the resistance on the tps. I was getting .8 ohms, which reached 1.1 ohms when the harness was wiggled. I'm not sure if that is significant enough to cause a ground issue. Its still not 100% but better than it was yesterday. What do you suggest I do now? Thanks cruiser for all of your help

Ok, so i did most of steps 1-5 when first putting the truck on the road about a year and a half ago. However I did not replace the braided chassis ground cable (i know i know no shortcuts). And here is some more background information, I have a pacesetter pos header with a y tube. I had the entire exhaust welded, but he said he couldent get to where the y pipe meets the header, because it hugs the block so tight. So he used exhaust clamps, but unfortunately put one on too tight and egged the pipe out. So what I'm getting at is there is a exhaust leak, BEFORE the O2 sensor, but NOT at the head. So here is what I did just today. 1) looked at side of block grounds. Everything good and tight 2) took off braided cable and cleaned cable, and firewall/head surfaces. Although everything looked fine. 3) took off wire loom and found a taped up crimped connection. 6 black wires going to one black wire, all same gauge. Connection seemed ok, slightly oxidized. I cut the connection out, and soldered/heat shrinked the wires. I disconnected the battery before I started any of this, and left it disconnected for probably 45 minuets. When everything was back together, it started right up but was ideling rough, but did not stall. A few hits of the throttle and it seemed to smooth out momentarily. I left it idle for about 5 minutes, then shut it off. Came back 15 min later, started right up and drove away. I could still feel the loss of power when moving, and idle had gotton worse. Drove it about 6 miles to my destination and the idle improved. Took it out again to several stores, could not feel any problems with it after i left the first store. Then on my antidisestablishmentarianism back home (my last tripof the night), I drove it for a consecutive 35-40 minuets, doing everytype of driving i could think of. I accelerated hard, downshifted hard, drove normally on a highway, nice and slow through a neighborhood with lots of stop signs, idling in a drive through line, back to driving it hard, etc. This whole time I could not feel any of the previous symptoms. I'm not sure what to think. While I was out I got the 4 gauge and terminals for the ground upgrade. So I'm going to throw that in tomorrow regardless, and I still have the bosch O2 sensor. Should I put that in too? Any thoughts?

Thanks guys. Yes I'm familiar with Cruisers tips. I still have not found time to eliminate the firewall pin connector (name escapes me), but I did clean it thoroughly. But yes I will double check the grounds again. However earlier today I had a second to look under the hood, and I DO have the sensor :doh: . For some reason I thought I didn't, too much other stuff on my mind lol. But behind that sensor, there is a fitting for a vaccum line. And that is indeed plugged off, I forgot to mention that in the original post. I know I researched it before, but could anyone refresh my memory on what that port is for? I will clean the IAT sensor, throw in the new o2 sensor just for kicks, and I'm going to order a MAP sensor from the dealer since the original one is in there now. That is the only sensor that I have not changed other than the IAT. Does anything sound wrong with that plan? thanks again