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Unread 07-06-2013, 10:20 PM   #346
row684
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So my CJ is laid up with a bum transmission so I took my brothers Cherokee out for a trail ride (low range) tonight (4.0,ax15,35's, unknown gears) I was not pleased with it. The 4.0 besides running smoothly at all angles and started easy it was not fun to drive...

Maybe it was the gearing or maybe that's just the way 4.0's drive but it was not smooth transitioning from an idle to light gas didn't want to move at idle wanted to take off at slightest amount of throttle. Bucked every time very unlike my 4.2 (t5 soon to be t176, 3:31's, 33"s) that is like a tractor through the woods at idle, silky smooth transition to gas

I have been wanting to drop a 4.0 in my 7 for quite some time but now I'm having second thoughts.

Is something messed up with his? Are they all this way? Gearing not matched to tires? Or do I just need to get used to it?

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Unread 07-07-2013, 09:43 AM   #347
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I believe the difference you speak of is the linkage. I swapped this spring (to a 4.6 Stroker). The 4.2 had a lot of crazy linkage, making for a stiff peddle. The 4.0 linkage is totally cable driven, this it can be more punchy. Just like anything else, you get used to it. I have learned to control it.
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Unread 07-07-2013, 01:02 PM   #348
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Quote:
Originally Posted by NelsonATC
I believe the difference you speak of is the linkage. I swapped this spring (to a 4.6 Stroker). The 4.2 had a lot of crazy linkage, making for a stiff peddle. The 4.0 linkage is totally cable driven, this it can be more punchy. Just like anything else, you get used to it. I have learned to control it.
This. I found the return spring on the 4L throttle much lighter. That combined with 35's and 3.55 gears is gonna make for a different experience than your CJ. Not to mention the 4L has a different power band than the 4.2.
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Unread 07-07-2013, 06:00 PM   #349
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Quote:
Originally Posted by jeepwhore

This. I found the return spring on the 4L throttle much lighter. That combined with 35's and 3.55 gears is gonna make for a different experience than your CJ. Not to mention the 4L has a different power band than the 4.2.
What is the power band differences?
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Unread 07-07-2013, 06:31 PM   #350
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4.2 has more on the low end , especially lower rpm's. 4.0 has more mid to high end power, and can rev higher.

Just stoke the 4.0 and get the best of both, plus some
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Unread 07-13-2013, 10:52 AM   #351
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I am installing a 4.0 in my son's 5 right now, and I am stuck! But then I'm always stuck. We are using a '97 engine (XJ 4.0) with a '92 harness. Engine harness is complete, including the PDC. Everything is mounted up. I have power at start/run, and the starter turns. I am unclear about the fuel pump relay, and which wire goes to the fuel pump. The fuel pump relay output wires are not hot in crank or run position. Also, I have no spark. Here is a link to our build thread. It should take you to the last page, or so. Would someone please have a look and see if you can help me get the needle out of the groove!?

http://www.jeepforum.com/forum/f8/cl...l#post15672433

Thanks
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Clay's Build Thread
http://www.jeepforum.com/forum/f8/cl...hread-1061897/
Scott's Build Thread
http://www.jeepforum.com/forum/f8/sc...5-cj7-1147913/
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Unread 07-14-2013, 03:07 PM   #352
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I had a similar problem on my swap.


In a nutshell, my problem was that my ECM was bad.

However, you need to check a few things first (I'm giving you this off the top of my head).

Make sure you have a good fuel relay.

Make sure you have a functioning automatic shutdown relay.

Make sure you have power to both

Can you jump the fuel pump relay and turn the pump on?

Did you install a 'Check engine' light? If so, you should turn on when you turn on the ignition.

You can also check the connector at the ECM To be sure that you have ground, and 12 V power at the appropriate points.

I went crazy chasing all this stuff down, until I realized that it was a bad ECM. The kid that I bought the harness from assured me that it was a working ECM, so I didn't immediately identify that as a potential issue. As soon as I put a new ECM, it fired right up.
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Unread 07-14-2013, 03:21 PM   #353
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I just quickly scanned your build thread, and have another question:

Are you still running the ballast resistor from the XJ harness? As part of my elimination process, I bypassed this resistor, cut the two wires, and soldered them together. Wranglers do not have ballast resistors, but run pretty much the same harness. I was told that for our set ups, they are not necessary.

I've been running mine that way for about 2 mos without issue.
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Unread 07-14-2013, 05:43 PM   #354
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Hey Nelson. Thanks for the reply. I spent a LARGE amount of time on the Net today, Googling things I never thought to Google. I wrote down two memo pages of notes... things to check when I got home.

No Spark, first- according to many different forums, especially Cherokeeforum, the CPS is the primary culprit in no spark at the coil. I have power in, but no sparky out. I was thinking I never plugged in the CPS, so I couldn't wait to get home. Once home, I discovered I did, indeed, plug it up. bummer. So I started reading my list of notes. I plugged in my O2 sensor (which was unplugged), I made sure I had power to my ballast resistor relay (not related to spark, buuuut) , and I checked my grounds. Now, I can't say for sure WHICH correction it was, but I'll bet dollars to doughnuts it was the fact I had never connected ANY of the three grounds for the ECM! Now I have spark! I am so friggin excited!!!!!

Ballast Resistor Bypass Relay, second- again, several of the forums I tapped into mentioned you could bypass the ballast resistor altogether, just as you have done. Virtually all of them state that it is only there to slow down your fuel pump speed, thus making it quieter. I don't know if it is a good idea to have your pump turning at full speed (in theory), but I dont know that it matters. I'm going to leave ours in place until it creates a problem. For now, it is working. I'm guessing... is the picture the ballast resistor bypass relay? It is connected directly to it, so it must be??

Fuel Pump Power Wire, third- I don't know where to get power for the fuel pump! I *thought* there would be a wire hanging out there that went to the fuel pump, from the PDC. But there ain't! Should I just rig it to a crank/run wire out of the bulkhead connector? Should I attach a separate relay for it?

Thanks, All...

edit* The label in the picture was for a previous post. You can disregard that!
cimg0394_1.jpg

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"Contemplate the mangled bodies of your countrymen, and then say 'what should be the reward of such sacrifices?' ... If ye love wealth better than liberty, the tranquility of servitude than the animated contest of freedom, go from us in peace. We ask not your counsels or arms. Crouch down and lick the hands which feed you. May your chains sit lightly upon you, and may posterity forget that you were our countrymen!" —Samuel Adams

Clay's Build Thread
http://www.jeepforum.com/forum/f8/cl...hread-1061897/
Scott's Build Thread
http://www.jeepforum.com/forum/f8/sc...5-cj7-1147913/
Fallon (and Dad) Build Thread
http://www.jeepforum.com/forum/f11/f...-okee-1445206/
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Unread 07-14-2013, 06:40 PM   #355
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The really pictured is your ballast resistor bypass relay.

If you don't want to eliminate your ballast resistor, but still see if it is part of the problem, just make a jumper for it. Unplug it on both ends, insert the wire into the two plugs, that's joining them together.

I took the two Green wire you identified before, wired them together with one single 12 gauge wire, and ran them back to my fuel pump.

Now that I've broken out my schematics, I'm realizing that I could have eliminated the ballast resistor relay, in the ballast resistor altogether, and ran one single wire back to the fuel pump directly from the fuel pump relay. On the wiring schematic I am looking at, it is the dark green/black wire running from the fuel pump relay. This would have simplified my fuel pump wiring a bit. If I have any issues down the line, this is exactly what I'm going to do.

The reason you're not seeing a fuel pump wire is because (And I'm guessing here little bit) That wire runs up into the bulkhead connector, and from there, joins the wiring for the rear tail lights and such, where it splits out by the fuel tank.

As far as getting power for the fuel pump, check and make sure you are getting12v power to the trigger wire (The wire that actually triggers the relay to turn on) If not, make sure that wire is still connected to the box. Then you can trace that wire back. Dark blue according to my schematic. The automatic shutdown relay also triggers off this wire.
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Unread 07-14-2013, 07:43 PM   #356
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Quote:
Originally Posted by NelsonATC View Post
The really pictured is your ballast resistor bypass relay.

If you don't want to eliminate your ballast resistor, but still see if it is part of the problem, just make a jumper for it. Unplug it on both ends, insert the wire into the two plugs, that's joining them together.

I took the two Green wire you identified before, wired them together with one single 12 gauge wire, and ran them back to my fuel pump.

Now that I've broken out my schematics, I'm realizing that I could have eliminated the ballast resistor relay, in the ballast resistor altogether, and ran one single wire back to the fuel pump directly from the fuel pump relay. On the wiring schematic I am looking at, it is the dark green/black wire running from the fuel pump relay. This would have simplified my fuel pump wiring a bit. If I have any issues down the line, this is exactly what I'm going to do.

The reason you're not seeing a fuel pump wire is because (And I'm guessing here little bit) That wire runs up into the bulkhead connector, and from there, joins the wiring for the rear tail lights and such, where it splits out by the fuel tank.

As far as getting power for the fuel pump, check and make sure you are getting12v power to the trigger wire (The wire that actually triggers the relay to turn on) If not, make sure that wire is still connected to the box. Then you can trace that wire back. Dark blue according to my schematic. The automatic shutdown relay also triggers off this wire.
I'll double check the Gr/Bk wires from the fuel pump relay. I know one of them goes to the heated O2 sensor, and the other goes to the ballast resistor bypass relay. I need to make sure of the voltage going to the bypass relay... if I have it right I can eliminate it as you say and use that wire to trigger my fuel pump. For now, I have the pump wired to crank/run at the BH connector. Pressurized the system, turned the key, and the dang thing started!
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"Contemplate the mangled bodies of your countrymen, and then say 'what should be the reward of such sacrifices?' ... If ye love wealth better than liberty, the tranquility of servitude than the animated contest of freedom, go from us in peace. We ask not your counsels or arms. Crouch down and lick the hands which feed you. May your chains sit lightly upon you, and may posterity forget that you were our countrymen!" —Samuel Adams

Clay's Build Thread
http://www.jeepforum.com/forum/f8/cl...hread-1061897/
Scott's Build Thread
http://www.jeepforum.com/forum/f8/sc...5-cj7-1147913/
Fallon (and Dad) Build Thread
http://www.jeepforum.com/forum/f11/f...-okee-1445206/
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Unread 07-14-2013, 07:59 PM   #357
NelsonATC
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What are you running for a fuel pump?
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Unread 07-14-2013, 08:03 PM   #358
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Quote:
Originally Posted by NelsonATC View Post
What are you running for a fuel pump?
E2000... you familiar with that one?
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"Contemplate the mangled bodies of your countrymen, and then say 'what should be the reward of such sacrifices?' ... If ye love wealth better than liberty, the tranquility of servitude than the animated contest of freedom, go from us in peace. We ask not your counsels or arms. Crouch down and lick the hands which feed you. May your chains sit lightly upon you, and may posterity forget that you were our countrymen!" —Samuel Adams

Clay's Build Thread
http://www.jeepforum.com/forum/f8/cl...hread-1061897/
Scott's Build Thread
http://www.jeepforum.com/forum/f8/sc...5-cj7-1147913/
Fallon (and Dad) Build Thread
http://www.jeepforum.com/forum/f11/f...-okee-1445206/
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Unread 07-14-2013, 08:07 PM   #359
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That's what i'm running. Works fine and holds good pressure
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Unread 07-14-2013, 08:11 PM   #360
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I was impressed how quickly it picked a prime. I think I'm getting more than 35# of pressure at the fuel rail. I don't remember what the desirable pressure is off the top of my head...
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"Contemplate the mangled bodies of your countrymen, and then say 'what should be the reward of such sacrifices?' ... If ye love wealth better than liberty, the tranquility of servitude than the animated contest of freedom, go from us in peace. We ask not your counsels or arms. Crouch down and lick the hands which feed you. May your chains sit lightly upon you, and may posterity forget that you were our countrymen!" —Samuel Adams

Clay's Build Thread
http://www.jeepforum.com/forum/f8/cl...hread-1061897/
Scott's Build Thread
http://www.jeepforum.com/forum/f8/sc...5-cj7-1147913/
Fallon (and Dad) Build Thread
http://www.jeepforum.com/forum/f11/f...-okee-1445206/
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