Jeep4xb4u's taking forever 4.6

[Jeep4xb4u]

oh crap, i got questions from you guys with little time to respond. I promise ill get back to these questions but i got the engine running with a couple problems.

I got the thing fired up and it was running real sluggish. I got it up to around 2k to start breaking in the cam and noticed that i couldn't get past 2200 without it sputtering, stalling out and back firing. So i kept it at 2100 for around 22 min. Temps climbed to about 230 towards the end then i turned it off. Checked everything under the hood, fired it back up and took it around the block a few times and noticed the same thing would happen with lots of back fire if i gave it too much gas in this range. Drove it around for about 10 min trying to get on it a bit as much as possible but was still fighting the 2k-2200 range. If you snap the throttle and jump past that range it smooths out and starts to pull but soon looses power @ about 3500. On top of this it struggles to idle above 300 rpm. Its real lopey and choppy at low RPMs.

I'm thinking i need to try reindexing the disty but have a hard time believing its just this seeing how it only happens through a few hundred RPM range and no where else. Its a serious enough problem that I'm concerned i have effected my break in procedure and cannot rely on it sitting at a light.

On the flip side when its not loosing power or bogging out... Its got balls and runs real smooth. No comment on the cam yet as i don't know if some of the choppiness at idle isn't due to its specs, but the cam specs are pretty mild to say the least.


Please advise if there is anything else i should be looking at other then the disty.

PS. AF ratio is reading 13.1 but im not sure if i got the thing set up right yet as it doesnt move from there no matter what you do to it. Got to bust out the autometer book.

[SilverXJ]

Yes, start with the distributor.

13.1 may be correct at one point, but it should be constantly moving around, not just sitting at 13.1 the whole time.

[Jeep4xb4u]

Well, i encountered the classic noob problem. Indexed the disty wrong! Reindexed it and runs good. Had to readjust the little idle screw on the throttle body, and adjust the TPS.

I took it out and ran it through the gears and RPMs while varying the loads trying to break it in some more. Almost every mile that went by it became more responsive and peppy.

I did figure out my AF ratio gauge problem. My mins and max's were set to close together. My range now goes from 10.1 to 16.1. Now it will drop down to 10.5 while getting on it and only go up to 13.6 while coming to a stop with no throttle. My fuel pressure is set to around 40psi and fluctuates down to about 35psi if you give it some throttle. I guess ill try to back down on the pressure some to see if i can get it pretty consistent.

More to come. And when i get time tonight ill answer those lingering questions. Thanks for letting me bounce my thoughts off you guys and for the fast replys.

~Justin

[SilverXJ]

Being yours is a renix rig I have no idea what AFR it is looking for, but newer vehicles look for 14.7:1 while crusing and idle. That 10.5 is quite rich. Might want to see if you can lean it up a bit. What injectors are you running?

[Jeep4xb4u]

Alright Silver, leaned it out a bit and got it to run a pretty consistent, 14.7 other then at WOT. Only concern i have is that i'm down to 20psi at the rail. It almost seems as if i have to large of injectors and i have to decrease pressure to compensate for them. Maybe running lower Lbs injectors at higher pressure would would not only get me back into the correct pressure for MPI but may also fix my top end lean problem.

My injectors are the 24lbs evo6, out of a 2005 mustang. Refer to this post: http://www.jeepstrokers.com/forum/viewt ... f=26&t=334

On a side note the thing runs strong. i'm very hesitant to give it to much in fear of blowing up my D35.

P.S.
Im running 33" crappy thornbirds that way a ton and i can get them (or one i should say) to spin with only about half throttle. Is the money worth while spent on a stroker? My vote is yes. It will prob pass smog. And there is little to no effort dropping this in compared to a V8 swap. Very! Very! satisfied with the time and money spent doing this. i'm sure ill have a Sh** eaten grin when i wake up and drive this thing to work tomorrow.

[lafrad]

Is the oil pan a factory replacement or an aftermarket high volume part?

[SilverXJ]

That is what I want to know. I couldn't find a Jeep oil pan on Milodon's website though.

[Exos]

I wrote "post cam break-in". The cam break-in should be done first.

[Jeep4xb4u]

Ok guys, thanks for everyones input and fast responses and i oppologize for my delay in answering your questions.

im interested in the alternator mounting and style. it looks like a delco CS series? or am i not seeing it right. either way, more info on the alt, mounting and belt routing please!

The alternator is in fact a Delco CS style. It’s a Power Master 140amp unit. The belt routing basically consisted of ditching the stock mechanical fan, removing the shaft a bearing assy for it from the bracket, shaving down some of the casting gussets, and making some brackets to bolt onto the previous A/C provisions. I’m currently reworking one bracket because I am not happy with the slight flex on bracket has while @ higher RPMS. I had that brand new alternator go out on me today and I am not sure if it has to do with some belt deflection or just a manufacture defect, but Power Master is taking care of me even know I am 10 months out of warranty on the unit. The Bearing became separated on the back side of it causing the alternator to squeal like I was loosing a belt and almost seized up leaving me stranded @ work and replacing it with my stock unit in the cold.

If you guys have any input or tips for belt lengths, tolerances and angles it would be good input while I rebuilt this one bracket. I am not completely convinced that its Power Masters fault and have looked into the possibility that my fabrication my be to blame. But so far the old alternator is working just fine.

The distance between my dampener and the pulley for the ALT is a bit long, but this isn't much different then some GM setups I've seen. Has me concerned because at idle RPMS the belt does have some noticeable bounce between those two pulleys. Get the R's up just a bit from idle and it goes away.

Belt Routing:

Brackets:

Damn... thats a nice looking engine. I must have missed it, but whats the info on the oil pan?

Thank you Silver for your compliment and your support during those first few days. You have a mighty fine looking XJ yourself. I don’t envy the problems you have had and pray I don’t experience them.:-/.

Not to bust any ones bubble seeing how I have had three inquiries on the pan, but it’s just a stock pan that has been stripped, plated, and snickered. I know... I cheat, but I’ve been drooling over those Milodon pans since I was about 16 when my uncle built a BB Mopar engine and slapped one on it. Since then him and I have always said Milodon needed to make one for the fairly large 4.0 market, but it’s never happened. My uncle being the owner of two of these pans showed receipts to Milodon and got two sets of replacement 4" stickers for his pans that are not available for purchase unless you own a pan and the idea came together when he had one spare. "Sorry Milodon, I just want your name on my engine, I am not trying to fraud you". So that’s the sad story on my pan. Looks neat under the Jeep, but far from the real thing or true proprietary gold color.

What paint/coating did you use on the valve cover and intake manifold? I like that look.

Thanks, it’s a black wrinkle powder coat very similar to what you would see on Mopar performance valve covers. My company uses this coating on a few of our products and I’ve always liked it for its finish and durability. Its one of the few powder coatings that I have came across that does well in applications that need to flex. It will still chip naturally but under heavy circumstances compared to most. I’ve watched them spray it and it goes on relatively smooth. It’s during the baking process that most of the wrinkles show up. Pretty neat and stays clean looking for a long time with little maintenance. If anyone is interested I could take cores and get them coated for them for a minimal fee or at least just get you guys the P/N of the product they use.

Some more genreral shots of the engine install.






Ill post more soon as I just ordered a new intake system and am working on finishing up some of the wiring and engine compartment clean up.

[amcinstaller]

the delco cs series ahd problems with bearings. particularly the rear bearings. had two seize and melt the casings. got one rebuilt locally and boosted to 140 with new bearings, havent had a problem since. i still have that one, this project makes me think about using it. thanks!

[Jeep4xb4u]

No problem. Good luck and let me know if you need any input if you decide to take on a similar project. Don't know if i can be much help as i'm still learning my self.

I haven't even sent back the PowerMaster disty yet. I've been too busy with work to find time. On a side note, the engine is running really good. Bit rough compared to the last engine but still shocking considering the mods that have been done. Sucking up a bit more gas then i would hope and its still running a bit lean, around 1.10 on lambda (bit easier to keep track of while driving) on average. Nothing concerning, but haven't wanted to tamper with it until i really felt like it was broke in. Smells good, pulls strong, and sounds nice. At this point i can only wonder what other peoples results have been like with larger modifications. i'm extremely happy with my patience and results with this project.

Just received shipment on my new AFE air intake system. It is designed for a 91+ but worked out extremely well with the adapter i picked up from hesco and contrary to what there dealers and disty's might claim on there website, its C.A.R.B. approved. Very good quality, good installation instructions, and top notch parts kit. Everything from every bolt that's needed, to american made Gates hoses were included. I was very impressed with the craftsmanship to price ratio. I personally can respect this seeing how i have help in the development in several products in the past, and its not an easy task to complete if your criteria is set high especially in the U.S.A . Mad props to AFE, and buy local, no matter where you reside. i'm sure that some of there stuff is built over seas due to global manufacturing, but any company that strives there hardest to keep the majority of it in the states, i support .

More pics and updates to come...

[Jeep4xb4u]

Little update, got the intake completely installed minus two bolts that i misplaced. Now i'm working on my rats nest of wire you can see in these pics. About a year ago i tore my whole harness out of the compartment and got rid of all of the factorys crimp and duct tape splices and replaced them with solder and headshrink. Also shortened up all the grounds and every wire that was excessively too long. Along with that i scrapped all of the diagnostic ports for the Renix stuff as i have never found someone with a scanner that can plug into to and i have no use for it myself. Now i'm going to finish cleaning up the remaining wiring that will travel to the injectors and sensors on my manifold. Its coming together slowly.

Couple questions though. I have noticed that the engine has got noticeably quieter over the past few weeks. I'm not referring to actual engine noise, this has got quitter but nothing will get rid of the noise of cold forged pistons, i'm referring to the exhaust tone. It seems almost week sounding it has me a bit concerned. Is this normal or should i be running some compression and leak down tests? It was real blurpy and deep shounding when i first got it fired up. Either im getting used to it or something is changing. Plugs look good and tan, both oil changes i have done looked great with no debris or discoloration.

On top of that i have been struggling with a rich fuel mixture problem. I'm running those 24lb injectors as stated previously at only 25 PSI at idle and it jumps up to about 30psi at full throttle. This as low of pressure i can run with the current Hesco F/P regulator and my A/F at WOT is 11.5 on average and wants to bog a bit.

Im already concerned about the low pressure at the rail and wouldn't want to run it any lower than 25 psi even if i had a way. Any ideas on what i can do to help even out my A/F throughout the entire power band on this renix system? How much power can i be loosing running 11.5 @ WOT? Do you think an adjustable MAP would take care of that big of a difference? Im not sure anything will work when it comes to sensors as at WOT its suppose to be in open loop mode right?


Any help please...

[gradon]

I would recommend using 22# injectors and then hopefully needing to turn up the fpr--you don't want the gas to dribble out(if you could go lower). The 12.5:1 is the lowest an N/A build should go(unless you have to go lower to eliminate ping) to achieve the best power. Some even find that 13.0:1 is best for power(but I think they are relying on the tune shop's clamp-on wideband at the tail pipe, which reads slightly higher than header/mid-pipe mounted widebands).

[Jeep4xb4u]

Thanks Gradon. This is exactly what i was thinking, 25psi seems a bit low considering that stock is right around 31 psi at idle on the Renix system i believe. The lower pressure might be effecting my spray pattern coming out of the injector itself. This is news i didn't want to hear due to the fact that i would be looking at buying new injectors but i guess thats what it will take. Do you know of any EVO 6 22lb injectors. I'm right in the middle of soldering the EVO6 connectors onto my stock wiring and replacing the old brittle stock ones. Is there any piggyback system i can use on my renix comp that may help me fine tune some in the higher RPMS? Are any of these SplitSecond or other piggyback systems fully universal in the sense that i can tap into any 5v signal and adjust its attributes.

[SilverXJ]

Are you sure the flow rating on those injectors is correct? It just doesn't make much sense to be at that low PSI and have such a rich afr. Are these new injectors?

As for the noise, now many miles on the engine now? Did you replace the exhaust while at it?