4bangerjp.com

General Forums => The Mess Hall => Topic started by: RickBrins on July 08, 2015, 08:41:11 PM

Title: 2.5 rebuild
Post by: RickBrins on July 08, 2015, 08:41:11 PM
1995 2.5, engine is out and apart, the good news is that it doesn't look too bad in side.  (Sorry, no pictures, I was not around for the teardown).  I will need a new cam and lifters and will see if the crank can be machined, I will have the block bored and surfaced, the other obvious gaskets, bearings, seals, oil pump, timing chain, etc.  Now the questions......
1) Stock cam or something else?  (Mostly a daily driver, highway,  light off road, 30x9.5 tires)
2) roller lifters?  (Are they worth the $450)
3) ignition?
4) injectors?
5) Anything else I am missing?

Mainly looking for an easier highway cruise, possibly a little more mpg, and reliability.

I have a 4.0 throttle body, headers and high flow cat and exhaust.  Other than that, ,it is mostly stock.  I made it to 240, 000 miles on this engine, would have gone longer, but my 16 year old does not understand the importance of oil.

I know there are many threads on here about mods, but I will listen to any suggestions you ,may have fopr my particular needs.

Thanks in advance!

I'm thrilled to be a member of this forum again, you all are very helpful and most are very knowledgable!
Title: Re: 2.5 rebuild
Post by: RickBrins on July 08, 2015, 09:50:07 PM
I forgot to add that I have a TB spacer.

I found a set of remanufactured Bosch Yellow top injectors for $100, are remanufactured injectors ok? Also it is a set of 8, does anyone want the other 4 if I get them?
Title: Re: 2.5 rebuild
Post by: RickBrins on July 09, 2015, 07:58:39 PM
So far, I am finding that...

 my best chance of Roller Rockers is Yella-Terra for $450, I'm still not convinced the gains will be worth the cost, but would love to hear frpom someone with experience

The FireWire Ignition System seems to be worth the time and money to install

The Bosch 19# injectors are cheap enough to give a try

Still unsure if I can find a performance cam, or if it will help me much with my typical drive

Slight bore to clean up the block

Any other thoughts?
Title: Re: 2.5 rebuild
Post by: grumpygy on July 09, 2015, 09:49:59 PM
Never heard of Fire Wire.  But I like http://performancedistributors.com/product/jeep/
Title: Re: 2.5 rebuild
Post by: RickBrins on July 09, 2015, 10:06:04 PM
That is the one I was looking at, I meant FirePower, not fire wire...but I liked what I saw and also read Jeffy's comments on it.
Title: Re: 2.5 rebuild
Post by: VA_YJ on July 10, 2015, 02:24:41 PM
You forgot about one important mod: the 2.5L Low Output sticker  :biggrin:

Regearing is the most significant performance mod, but with 30" tires and your uses/objectives it doesn't make sense.
Title: Re: 2.5 rebuild
Post by: RickBrins on July 10, 2015, 02:32:51 PM
The machine shop has the head and crank to do what is necessary to get that much together, still not sure how much over I will have to bore, but I trust the shop.

1) I gave up on a performance cam, I guess I will just go new stock with lifters.

2) I have the Bosche stage III injectors ordered.

3) I have decided on the Jeep FirePower Ignition Kit

4) Gonna pass on the Roller rockers, just don't see the benefit for the $450

5) New Oil pump and timing chain

6) New water pump

7) Seals, bearings, and gaskets

8) slight port and polish on the heads

Next question.....what else should get some attention before it goes back in?

Any other sensors, vacuum lines, etc?
Title: Re: 2.5 rebuild
Post by: RickBrins on July 10, 2015, 02:34:43 PM
Thanks again for taking the time to offer advice!
Title: Re: 2.5 rebuild
Post by: RickBrins on July 10, 2015, 02:38:36 PM
You forgot about one important mod: the 2.5L Low Output sticker  :biggrin:

Regearing is the most significant performance mod, but with 30" tires and your uses/objectives it doesn't make sense.

I agree totally, I think the stock gearing is sufficient for now.  Not really looking for killer power and don't expect it out of this engine, also don't expect fabulous mpg, but a little more of both might be nice if I can find it.  While I have it apart.

I'm designing my sticker now. :dance:
Title: Re: 2.5 rebuild
Post by: VA_YJ on July 10, 2015, 03:02:12 PM
http://www.pixeldecals.com/shop/2-5L-Low_Output-Decal
Title: Re: 2.5 rebuild
Post by: DanMarino on July 21, 2015, 06:50:15 AM
My 1994 2.5 has 200,000 miles.  So how did you know that your engine needed to be rebuilt?
Mine runs great, but I was wondering when it makes sense to put on a new timing chain set, or what would be an indicator that the engine needed to be replaced or rebuilt?

Thanks,
Tom
Title: Re: 2.5 rebuild
Post by: RickBrins on July 21, 2015, 07:50:30 AM
At 240,000 miles I got a great indicator that it was time to rebuild, my 17 year old son drove it for a a couple of months and never checked the oil, the rod knock was obvious to me, he thought it sounded a little off.

If yours is running good, drive it, if you have the time and $, freshen it up, but I think I could have gotten 300,000 + out of mine if it had oil in it. :brick: :brick: :brick:
Title: Re: 2.5 rebuild
Post by: special4 on July 21, 2015, 10:24:43 AM
Hello
What car use this bosch stage3 injectors? who make the fire power ignition kit? do you have more torque in lower rpmīs or higher ?
thanks
Title: Re: 2.5 rebuild
Post by: RickBrins on July 21, 2015, 10:33:03 AM
I am still waiting for the block to come back from the machine shop, so I don't know exactly what I will see different, but according to the posts on here that talk about them, they are good mods.

The injectors are Ford GT injectors, I found rebuilt ones on eBay, set of 4 around $65.

Performance Distributors makes the FirePower ignition.

Both mods have really good posts on the boards with excellent information.
Title: Re: 2.5 rebuild
Post by: jfrabat on July 22, 2015, 09:29:19 AM
For some reason, my Jeep does not like the screaming demon coil.  I keep burning them...  I know I am the odd one out there, but I have gone through 3 of them already, so I kind of gave up on them.  Other than my case, i have not heard any complaints from other users, so it must be something with my Jeep.
Title: Re: 2.5 rebuild
Post by: RickBrins on July 22, 2015, 10:39:08 AM
I'm hoping I have better luck with mine.

The block will be back this week, they had to bore 30 over. I was hoping 10 would be enough, but I guess the extra displacement won't hurt. Does anyone know what 30 over would increase the 2.5 to?
Title: Re: 2.5 rebuild
Post by: jfrabat on July 22, 2015, 11:55:45 AM
Just for reference, I would not expect performance gains from a 30 over...  But you can calculate the displacement with the formula:

πr^2 x stroke x # of cylinders = 3.1416 x radius(squared) x stroke x # of cylinder

Felipe
Title: Re: 2.5 rebuild
Post by: RickBrins on July 22, 2015, 07:54:23 PM
Thanks for the formula, I kinda ballparked some of the numbers earlier after figuring out the formula myself. 30 over is not really much different and no, I don't expect to notice any change from that. I have expect I will send the biggest difference just from the fresh build and tighter tollerences.
Title: Re: 2.5 rebuild
Post by: paulsadog on August 13, 2015, 06:07:26 AM
I am still waiting for the block to come back from the machine shop, so I don't know exactly what I will see different, but according to the posts on here that talk about them, they are good mods.

The injectors are Ford GT injectors, I found rebuilt ones on eBay, set of 4 around $65.

Performance Distributors makes the FirePower ignition.

Both mods have really good posts on the boards with excellent information.


Do you have a part number on those injectors?  I also have a 2.5l and have been doing some reading about upgrading from stock injectors. I spoke with a tech from Bosch and was told that they, Bosch, never made an injector for the 2.5l. That's not to say there isn't 1 that will fit its just Bosch never engineered 1. Here is 1 thread I was reading,

http://4bangerjp.com/forums/index.php/topic,3479.0.html

So what I get from looking into different injectors is that you may be able to get away with a 19lb injector but nothing higher for the 2.5l. In my little brain this makes sense because the PCM has been programed for a 17lb injector but I can believe the PCM has some flexibility to compensate for a somewhat flow rate.

Your thoughts?
Title: Re: 2.5 rebuild
Post by: RickBrins on August 13, 2015, 11:20:02 AM
The injector part number I used is Bosch 0280155700 I'm just getting the engine back in this week,  so I will have to let you know how they do.  They are the 4 hole 19# Injectorsand I am putting on a Standard Motor Products PR211T Fuel Pressure Regulator that bumps the pressure up slightly in the fuel rail.  If my research is correct the slight bump in pressure should help with the higher pressure Injectors.  Again,  I will see once I get it all in and running.
Title: Re: 2.5 rebuild
Post by: grumpygy on August 13, 2015, 10:31:14 PM
For some reason, my Jeep does not like the screaming demon coil.  I keep burning them...  I know I am the odd one out there, but I have gone through 3 of them already, so I kind of gave up on them.  Other than my case, i have not heard any complaints from other users, so it must be something with my Jeep.

Question cause this just hit me.  I'm running the screaming Demon No Problem.  But I have a late 94 build YJ.  Wonder if one of the Other changes that year was in the Distributor. Maybe the earlier ones takes a different Ohm coil than the late year. 

The reason I know is I has to change my axle bearings, the cross bearing.  They went with a larger size later in the year and I got the small ones not knowing any difference.
Title: Re: 2.5 rebuild
Post by: jfrabat on August 16, 2015, 08:25:52 AM
Question cause this just hit me.  I'm running the screaming Demon No Problem.  But I have a late 94 build YJ.  Wonder if one of the Other changes that year was in the Distributor. Maybe the earlier ones takes a different Ohm coil than the late year. 

The reason I know is I has to change my axle bearings, the cross bearing.  They went with a larger size later in the year and I got the small ones not knowing any difference.

As far as I know, there was no changes...  But I could be wrong!
Title: Re: 2.5 rebuild
Post by: RickBrins on August 19, 2015, 11:00:36 AM
Engine is in, nothing super noticeable yet,  but still only 50 miles on the break in.  However,  I am getting a lean code 51. Could that be the computer still trying to adjust to the new Injectors and pressure Regulator, on do I need to look at something else?
Title: Re: 2.5 rebuild
Post by: RickBrins on August 19, 2015, 11:21:25 AM
Engine is in, 50 miles into break in.  No real noticeable changes yet,  but I will give it some time.  I am getting a lean code 51 at highway speeds, could that be because the computer has not caught up with the new Injectors and pressure Regulator yet,  or do I need to look at something else?
Title: Re: 2.5 rebuild
Post by: jfrabat on August 19, 2015, 07:27:40 PM
Engine is in, 50 miles into break in.  No real noticeable changes yet,  but I will give it some time.  I am getting a lean code 51 at highway speeds, could that be because the computer has not caught up with the new Injectors and pressure Regulator yet,  or do I need to look at something else?

Don't think so.  I did the change, and did not get a lean code.  And if it were the case, you would be running rich, not lean, as the more pressure and larger injectors would result in more fuel if the time was set for the old injectors...  There might be something else going on.
Title: Re: 2.5 rebuild
Post by: RickBrins on August 19, 2015, 10:02:30 PM
I only get the code 51 when I drive at wide open throttle.
Title: Re: 2.5 rebuild
Post by: jfrabat on August 19, 2015, 10:24:30 PM
Check your TPS...  Mine was acting up and causing some issues some time ago...
Title: Re: 2.5 rebuild
Post by: RickBrins on August 19, 2015, 10:28:23 PM
The code is. . .  51: Oxygen sensor stuck at lean position. .  So is that maybe telling me that I am running rich so the O2 sensor is stuck full lean trying to lean it to the proper ratio? . Also,  the Highway power seems lower than before, is that still due to the break on period,  maybe a result of the improper fuel mixture,  or the computer still trying to settle in?

 
Don't think so.  I did the change, and did not get a lean code.  And if it were the case, you would be running rich, not lean, as the more pressure and larger injectors would result in more fuel if the time was set for the old injectors...  There might be something else going on.

The Computer was powered down for a couple of weeks,  so it probably wasn't set for any configuration.

What fuel pressure Regulator did you use?  Did you make any other changes,  and did you notice more power, better MPG, or both?
Title: Re: 2.5 rebuild
Post by: Jeffy on August 20, 2015, 02:02:29 PM
I only get the code 51 when I drive at wide open throttle.

That makes sense if you're using the OEM fuel regulator.  The Jeep wants 17.4# but when you're at WOT with 19# injectors at the lower pressure, you're only making 17.2#.  It's not a problem when not at WOT so it should be okay.  If you're going to go WOT then you'll want to convert the fuel system from 36# to 42#.  The only problem is bypassing the stock unit.  Member sharpxmen has done it with his engine.  It's somewhere in the Projects.
Title: Re: 2.5 rebuild
Post by: RickBrins on August 20, 2015, 02:36:40 PM
I put a 41# fuel pressure regulator on it, I believe the range is 41-50#.  It is off a chrysler 6 cylender or something.

We had to re-use the exhaust donut on the Banks header because I could not find a new one, it is possible that the issue is an exhaust leak.  Anyone know where I can get A Banks donut gasket? Auto zone, Pep Boys, anything.
Title: Re: 2.5 rebuild
Post by: Jeffy on August 20, 2015, 02:56:47 PM
I put a 41# fuel pressure regulator on it, I believe the range is 41-50#.  It is off a chrysler 6 cylender or something.

We had to re-use the exhaust donut on the Banks header because I could not find a new one, it is possible that the issue is an exhaust leak.  Anyone know where I can get A Banks donut gasket? Auto zone, Pep Boys, anything.

Did you check the pressure at the rail to varify?
Title: Re: 2.5 rebuild
Post by: RickBrins on August 20, 2015, 02:59:04 PM
I will be doing that tomorrow, if I read properly,  I want around 44#?
Title: Re: 2.5 rebuild
Post by: RickBrins on August 21, 2015, 06:02:07 PM
The fuel pressure read between. 42# and 46#, I even watched the guage as I drove at highway speeds to make sure the pump and pressure were keeping up at high flow,  so it seems that the lean condition is coming from something else. I did a spray test around the intake manifold,  and checked all vacuum lines.  I will be putting a new exhaust (donut)  gasket on as soon as ups delivers it,  and after that I'm hooking up a wide band o2.  I'm trying to avoid a new o2 sensor until the break in oil is changed, I'm told that the additives are tough on them.

It runs smooth and strong low end, a little weak at the normal range that the 4 banger struggles. I was hoping for just a bit more,  but maybe when I get the code 51 figured out things will be better.
Title: Re: 2.5 rebuild
Post by: sharpxmen on September 30, 2015, 10:19:57 AM
The code is. . .  51: Oxygen sensor stuck at lean position. .  So is that maybe telling me that I am running rich so the O2 sensor is stuck full lean trying to lean it to the proper ratio? . Also,  the Highway power seems lower than before, is that still due to the break on period,  maybe a result of the improper fuel mixture,  or the computer still trying to settle in?

 
The Computer was powered down for a couple of weeks,  so it probably wasn't set for any configuration.

What fuel pressure Regulator did you use?  Did you make any other changes,  and did you notice more power, better MPG, or both?

 what's your fuel pressure at idle with and without the vac line attached to the pressure regulator, if you have 50psi without the vac line (if that's what you meant by 41-50 as in 41 idle 50 wot) then it's way too much compared to 39 stock., there's no reason to go that high and could explain the code
if that's not it is the O2 sensor new? if not I would give that a shot and see if it fixes it.
Title: Re: 2.5 rebuild
Post by: RickBrins on September 30, 2015, 02:41:56 PM
Update..... About 250 miles on the engine it developed a bad miss in number 4. It turned out to be a plugged or bad injector,  so the stock Injectors are back in.  I was still getting a lean code. Hooked up a wide band o2 sensor and under most conditions all was normal,  but once at highway speeds for a few minutes it would go very lean and throw a code (51) and stay lean no mater what speed/power changes were made.  After a few minutes things would go back to normal. Removed and replaced the new o2 sensor and test drive generated no codes.  It was late,  so wide band drive will be today.  (the battery died in the wide band computer yesterday and had to be charged)  I expect better readings.  Also hope to have better power if the lean condition is fixed.
Title: Re: 2.5 rebuild
Post by: sharpxmen on October 14, 2015, 02:27:17 AM
Update..... About 250 miles on the engine it developed a bad miss in number 4. It turned out to be a plugged or bad injector,  so the stock Injectors are back in.  I was still getting a lean code. Hooked up a wide band o2 sensor and under most conditions all was normal,  but once at highway speeds for a few minutes it would go very lean and throw a code (51) and stay lean no mater what speed/power changes were made.  After a few minutes things would go back to normal. Removed and replaced the new o2 sensor and test drive generated no codes.  It was late,  so wide band drive will be today.  (the battery died in the wide band computer yesterday and had to be charged)  I expect better readings.  Also hope to have better power if the lean condition is fixed.
at wot the o2 sensor won't fix the lean state since it's open loop (the o2 reading has no influence on the mixture)
Title: Re: 2.5 rebuild
Post by: RickBrins on October 14, 2015, 08:34:21 AM
New o2 sensor did solve the check engine light.  When the old (new) o2 sensor would get stuck in lean mode the wide band o2 sensor would show that the engine was running lean in all throttle ranges for 5 or 10 minutes before returning to normal. . New o2 sensor solved the issue.
Title: Re: 2.5 rebuild
Post by: kashola on January 20, 2016, 06:36:00 PM
Glad you got your issue sorted out.  Just wondering how well it runs with the bigger injectors and FPR.  I tried the yellow Ford injectors on my Jeep with stock FPR and the old girl did not like it.
Title: Re: 2.5 rebuild
Post by: RickBrins on January 21, 2016, 06:29:02 AM
One of the injectors had a problem from the start and was not working, so the original injectors are back in, and I never was able to determine if the 19# injectors were a good idea or not. Having a fresh build has helped enough for what I need, although I was hoping for a little bit better mpg.
Title: Re: 2.5 rebuild
Post by: sharpxmen on January 23, 2016, 07:56:17 AM
they atomize better, minor improvements otherwise (flow is almost identical at the operating pressure for YJ)
Title: Re: 2.5 rebuild
Post by: kashola on January 23, 2016, 10:03:12 AM
From what I've read, the yellow tops flow more than has been reported by some.  I believe this to be at least part of the issue with mine.  With the higher pressure you're running, it may be causing some of your mileage issues due to more fuel volume in open loop.  What are you getting?  I have since switched to a different set of later style injectors and they seem to be a little better.
Title: Re: 2.5 rebuild
Post by: RickBrins on January 23, 2016, 05:50:00 PM
I went back to all stock, injectors and regulator. I still have the high energy ignition, but no change in mpg, still the same as before the rebuild... 15 mpg.
Title: Re: 2.5 rebuild
Post by: sharpxmen on February 07, 2016, 07:49:03 PM
From what I've read, the yellow tops flow more than has been reported by some.  I believe this to be at least part of the issue with mine.  With the higher pressure you're running, it may be causing some of your mileage issues due to more fuel volume in open loop.  What are you getting?  I have since switched to a different set of later style injectors and they seem to be a little better.
they flow slightly less (but just, not a concern)