98ZJ 4.6L Stroker Build

[FlyinRyan]

Tunes, yes, but pricing has changed due to demand, changes in hardware, etc.

[purple_jeep]

Well 100+ miles and things seem to be getting better I think I am feeling more power as the ecu learns the new settings. Still will need a tune at some point if not a flying Ryan tune at least a map adjuster but need an AFR log first.

I will pull the spark plugs on sat morning to see what they show.

Cheer's

Chris

[purple_jeep]

150 miles now,

Oil pressure looks good at operating temp:
Idle 30psi
Running 45psi

Long Term Fuel Trim is about 15% average seems a little high maybe? I am using Bosch 0280155703 21.5lb/hr @ 39psi & 24.0lb/hr @ 49psi which should be right? I will check my fuel pressure later today or tomorrow.

Spark plugs look pretty clean to me not sure exactly how to read these so let me know what you all think

IMG_20140927_094729.jpg

IMG_20140927_094740.jpg

Yes #1 is not shown as I need a 3/8" extension to get on the spark plug properly as my 1/2" drive does not go on straight with the AC compressor in the way.

Cheers

Chris

[SilverXJ]

A little hard to tell anything from the plugs.. not close enough to the tip nor large enough. They look clean, which is good. What you really want to watch for is little specs of black or silver on the porcelain. If you see that you are detonating.

[purple_jeep]

SilverXJ, I will get some closer pictures of the plugs this weeekend, also hope to borrow a compression tester to see how I stand on that also.

So Friday lunch time I did the 500 mile oil change and refilled with the same Amsoil synthetic and Amsoil EA filter then left for a ~650 mile round trip to a campground near Flagstaff Arizona from Tucson. Trip was great and car performed well enough other than breaking a end link on my sway bar and then experiencing "Death Wobble" for the first time on the way back most likely due to only one end link connected.

As for performance of the Stroker I was not that impressed, I think it did slightly better than the stock motor with 200k miles on the big hills etc. MPG was about 18 overall. I used Torque android app to data log the whole trip (still to get an AFR meter) LTFT got upto 30% as we went up in altitude.

After we got home earlier today I hooked up a fuel pressure meter to the injector rail and after purging the gauge and turning the key a few times to pressurize the line it sits at ~41 PSI which seems to indicate I have an issue with fuel pressure?

Also when running the needle bounces around should it be stable?

https://www.youtube.com/watch?v=eLxtL04 ... KROzqppDtw

I have been thinking I need to improve the engines breathing as I have a modified exhaust (Doug Thorley Header, Kolak Cat and back mandrel bent 2.5", new 2.5" down pipe (need to replace with mandrel bent at some point)) but stock filter box and flat filter, stock TB and intake but with such high LTFT I would not be able to use the extra air would I?

Thoughts?

Cheers

Chris

[SilverXJ]

As for performance of the Stroker I was not that impressed, I think it did slightly better than the stock motor with 200k miles on the big hills etc. MPG was about 18 overall. I used Torque android app to data log the whole trip (still to get an AFR meter) LTFT got upto 30% as we went up in altitude.

I might have missed it, but what are you using for injectors?

~41 PSI

Pressure should be 49 psi +/- 5 psi. 41 is way out of spec. Fix the problem (pump, regulator, and/or filters). Reset the PCM then taking a reading of the trims again.

Also when running the needle bounces around should it be stable?

It should be fairly stable.. that is nearly comical.

I have been thinking I need to improve the engines breathing as I have a modified exhaust (Doug Thorley Header, Kolak Cat and back mandrel bent 2.5", new 2.5" down pipe (need to replace with mandrel bent at some point)) but stock filter box and flat filter, stock TB and intake but with such high LTFT I would not be able to use the extra air would I?

Breathing improvements will definitely help. You have the exhaust almost taken care of (aside from the down pipe) and a throttle body and a cold air intake will help. However, you need to sort out the fuel issue. Also, if you don't have a wideband you have no idea what is happening under WOT/open loop so you don't know if its running lean ther.e

[purple_jeep]

I am using Bosch 0280155703 21.5lb/hr @ 39psi & 24.0lb/hr @ 49psi which should be right?

Yeah I know I need an AFR, that and a tune eventually.

Cheers

Chris

[FlyinRyan]

Chances are your fuel pump is tired, you may as well upgrade to a Walbro 255 pump. It is overkill but after seeing guys have to drop the tank multiple times to replace crappy parts store pumps, its best to get something that is going to handle your stroker and more.

As far as the TB, I would suggest either a 4.7 WJ/Dakota 68mm TB, or a F&B TB . Your fueling situation needs to be addressed first, however.

[purple_jeep]

That was going to be my next question OEM replacement or if there was another option. Walbro 255 it is then!

So what would be the order of intake changes? Not sure I can do them all at once?

1.) Cold air cone filter
2.) Bored throttle body/replacement 68mm TB
3.) 1999+ intake with curved runners

Where on the list should I get the down pipe replaced with a mandrel bent version?

AFR meter and tune first or last?

I just want to do it in a logical order since I can't do it all at once

Cheers

Chris

[jeepxj3]

Chances are your fuel pump is tired, you may as well upgrade to a Walbro 255 pump. It is overkill but after seeing guys have to drop the tank multiple times to replace crappy parts store pumps, its best to get something that is going to handle your stroker and more.

Isn't the 255 a bit way overkill? IIRC it can supply fuel for like 600HP.
Would the 190 be a bit more inline with what is needed? IIRC it can supply like 400-450HP.

Why use such an 'overkill' fuel pump on a stroker engine that makes under 300HP?

The manifold opening will have to be opened up for the 68mm TB and you don't want to do that with it attached to the engine.
So the '99+ curved manifold and 68mm TB really need to be done together. Or at minimum, at least the '99+ done first after it's opening has been opened up for the 68mm TB, then the 68mm TB can be added at a later date.

IMO, Fuel pump first (it's bad), AFR meter, CAI, '99+ manifold, 68mm TB, 2.5" downpipe. Tune can be done any time but is expensive.

[FlyinRyan]

Chances are your fuel pump is tired, you may as well upgrade to a Walbro 255 pump. It is overkill but after seeing guys have to drop the tank multiple times to replace crappy parts store pumps, its best to get something that is going to handle your stroker and more.

Isn't the 255 a bit way overkill? IIRC it can supply fuel for like 600HP.
Would the 190 be a bit more inline with what is needed? IIRC it can supply like 400-450HP.

Why use such an 'overkill' fuel pump on a stroker engine that makes under 300HP?

The manifold opening will have to be opened up for the 68mm TB and you don't want to do that with it attached to the engine.
So the '99+ curved manifold and 68mm TB really need to be done together. Or at minimum, at least the '99+ done first after it's opening has been opened up for the 68mm TB, then the 68mm TB can be added at a later date.

IMO, Fuel pump first (it's bad), AFR meter, CAI, '99+ manifold, 68mm TB, 2.5" downpipe. Tune can be done any time but is expensive.

I always plan ahead .......

[purple_jeep]

The 255 with install kit on Amazon comes out at $93.12 so that's not too bad, do I need to replace the filter regulator also? It seems to be good as it held the pressure on the leak down test. They are as much if not more than the pump at least on O'riley auto parts

Cheers

Chris

[SilverXJ]

Since you have a fuel pressure issue I would also replace the regulator.. unless you want to try just the pump first.

[purple_jeep]

Well since I have a 98 it is mounted on top of the fuel pump module so I don't think I want to drop the fuel tank too many times

Any suggested brands for the combined filter/regulator unit?

Cheers

Chris

[SilverXJ]

Bosch, Delphi, or Denso... not 100% sure about Carter.. but definitely not Airtex, Retech, or Spectra.

I've also heard good things about the Walbro performance pump if you would like to go that route.


Oops.. I misread that.. that is for the pump lol..

I don't see many options for the regulator besides BWD and Standard.