Jeep Strokers

I decided to go with the LM-2, i liked the logging features and the software to go with it. I think it should be very useful in coordinating a 3D fuel map for the PSC1-003. Looking forward to getting it all together next week. In the mean time, everything seems to be running pretty good

So i am a little let down......

I received my LM-2 today. Calibrated it as per the instruction, installed the o2 sensor in my extra bung, and fired it up. Idle'd at 14.6-14.8 AFR, So that looked good. The ENTIRE time that i drove the jeep, the AFR always stayed pretty close to 14.7. No higher then 15.0, and no lower then 14.5..... Even with the pedal smashed to the floor. So now i feel like i wasted money on the PSC1-003, because i haven't hooked it up yet, and my AFR's seem to be right where they need to be for daily driving and over all performance. It also disappointed me because my gas mileage is a lot worse then it was with my old tired renix engine.... I haven't been lead footed either, just giving it a healthy 0 to 60 off of a stop light every now and then. I'm down to almost as little as 10 MPG.... Good think gas prices are going down

I suppose the positive spin on things, is everything seems to be tuned pretty well...

The pcm will try to maintain that 14.7 as long as it's in closed loop. What you're not seeing right now are the fuel trims that show where the pcm is adding/pulling out fuel. You'll use the psc1 to try to zero those fuel trims so that the pcm will do little adjusting and then when you get to open loop, you can dial whatever afr you want. Also your open loop warm-up idle might be lean, where it should be rich, you dial that in too.

How can you tell how much the ECU is compensating for?

again, WOT seemed to burn at 14-14.7, either that or i'm not achieving WOT.

I'll test warm up this morning.

With the obd2, the lm2 or other scanner w/ live obd2 data can show long term and short term fuel trims(also when it goes from closed loop to open loop). So say mine at idle, the st fuel trim is 10-15, which means the pcm is adding fuel(negative # means the pcm is pulling out fuel) to get that 14.7 ratio. I will then go into the psc1, see what cell is highlighted at idle and increase the number until I've brought that st fuel trim to 0(a value of 10 keeps it the same). Now I like the resolution of the pressure on the psc1, but not too fond of the 500rpm increments(should be 100, or at least 200 imo). Anyhow you are gonna have to log some runs and see if you can pickup the fuel trim fluctuations(try to catch that 15+ b4 the pcm brings it down to 14.7). Now WOT you want to see 12.5:1 AFR or else you won't be making the power that you could be. I basically had to turn those cells up to the 25 max value on the psc1 to see the 12.5. I've been slacking on finishing my tune, but hopefully it'll be done by the new year.

MORE BOKEN PIECES!!!

Last night, on my way home, i launched hard off of a stop sign. It was really my first time jumping on it from a stop. At about 20 MPH all i heard was S-N-A-P.... and no drive....

So i grabbed the 4wd lever and made it home. I was disgusted and it was 1:30 in the morning, so i still have yet to look at what happened. But i did verify that the driveshaft was still connected. Maybe i snapped one of my 2 week old axle shafts?? *sigh* i guess i need to start looking for an axle upgrade......


WOT seems to run about 13.8-14 range. I want to make some recording of 4K and higher runs, as i can feel the truck loose power hard over 4300, which is right about where my peak HP should be

COOL! Lots of POWER!

Mgardiner1 wrote: WOT seems to run about 13.8-14 range. I want to make some recording of 4K and higher runs, as i can feel the truck loose power hard over 4300, which is right about where my peak HP should be

That is a bit lean for WOT. Some people suggest that 13.5 is good for WOT, but 12.5 is richer and safer.

dwg86 wrote:COOL! Lots of POWER!

no NOT cool! i mean AWESOME power, but i've dumped 5k into this heap between the engine and transmission swap this year. Last thing i feel like doing is SPENDING MORE MONEY!!!

You do know Jeep= Just Empty Every Pocket... right?

So i've been looking through evilbay....

I'm thinking a D44 is a decent choice, but i'm thinking a ford 8.8 might be a little beefier.... Late 90's ford explorers had them with disc brakes in the rear....

I think i should autopsy first and see what went wrong. I'm 99% sure it was an axle or something in the rear, as the driveshaft is still intact

Mike I run a 14 bolt in the rear of the YJ (full width) and a 8.8 in the rear of the TJ. I really like the 8.8 axle, The one you want is from a Ford Explorer, The Explorer has the large shafts and is slightly less strong than a rear Dana 60. Some might find it having c clips objectional though, several of us run them around here and have no problems with them. Try and get the e brake cables with the axles.
John

Cool i appreciate the information. The 8.8 is what i've been searching for the most. What kind of stress have you and your group of guys been putting these 8.8's through? I do not like the idea of the c-clip axles.... but then again i don't like the idea of my light duty D35 that is apparently not a match for my sweet running stroker!

How do you like the 30AB cam?

Well, i'm not really at liberty to say.... OVERALL the engine is a great performer (as indicated by my broken rear axle). I have a dead spot that makes the engine flatten out instantly at 4300ish RPMS which is just after peak torque, but right before peak HP for this cam. I need to get my axle situation sorted out, and then take some good WOT runs in high gear to find out what the fueling situation is doing. I'm not going to install my PSC1-003 until i find something i don't like, if it goes real lean or rich during that flat spot i'll install it, otherwise i'll probably evilbay it because the ECU seems to be doing a fine job of AFR.