Jeep 7747 Conversion

[EagleMark]

My old full size Blazer had a 700R4 but I thought it was a NP241? It did have a chain from Dogde diesel and the Slip Yoke Eliminator with CV joint. But in that truck the VSS in behind the speedo...

If it's just an offroader there's no need for the TCC. For the offroading around here it's all slow rock crawling and although I had WOT tuned and TCC I never used it...

Not sure but if it were me I'd run the 4.3L injectors, if they are not enough add a adjustable regulator and bump up pressure. That's always worked for me.

[PJG1173]

My old full size Blazer had a 700R4 but I thought it was a NP241? It did have a chain from Dogde diesel and the Slip Yoke Eliminator with CV joint. But in that truck the VSS in behind the speedo...

If it's just an offroader there's no need for the TCC. For the offroading around here it's all slow rock crawling and although I had WOT tuned and TCC I never used it...

Not sure but if it were me I'd run the 4.3L injectors, if they are not enough add a adjustable regulator and bump up pressure. That's always worked for me.

somewhere in the late 80's after the NP208 was phased out the full size chevy's were the NP24x, S-series and CJ, YJ, etc were NP23x. very common to take a NP231J and put a NP231C chain, cogs, and back half on the J case.

I ran my 4.3 injectors at 15.5 PSI and idle quality was still good. the pulse width and DC started to get high around 5000 RPM near peak HP for my aftermarket cam, so I went with the 5.7's at stock pressure to provide the fuel I needed over 4500 rpm. chances are your stock cam really won't be flowing enough air to require more fuel than those injectors can handle over 4500 RPM's. running the 5.7 injectors has affected my idle and if I let it idle too long sometimes it will flood out. Of course that still could be the tune but i never had the problem with the 4.3.

[JeepsAndGuns]

Again, I'm not entirely sure but I know its a mutt of parts from both jeep and Chevy. I know for sure I used the planetary gearsand chain from the chevy because i had to swap them in which is why I think it is a jeep case. Also I do not have a VSS present (part of my problems) and stock speedometer. It's been a few years since I did it and everything on this jeep was custom so its hard to keep it all straight....should've written it all down

Its no big deal. If your no longer running the factory spedo, then that answers my question. I was just curious about using the stock vss without the stock ecm, since the stock vss gets power from the stock ecm.

[crash8212]

Yes, the full size used the NP241 while S-series (where engine/trans/tcase came from) and Jeep used the NP231 variation. I am not overly concerned with the TCC as the Jeep rarely sees 55+mph with 37" Boggers that get very angry when driven on concrete. It is meant to be stored at our cabin and only used to cruise the 2-tracks and never have trouble getting through a hole or through the woods. We did go a bit overboard but its a riot to drive and was a blast to build.

Didn't get a chance to check on the fuel pressure and charging system today but hope to tomorrow or Thursday. After doing some brainstorming, the fuel pressure/volume (or lack there of) seems a likely candidate as the pressure drops on acceleration (seems like it hit 8-9 psi) at WOT but nearly stalls out. Could be the regulator, bad wiring, or a weak pump. I will tear into is soon to figure that out, hoping all the while it put me back on track. I will throw the 4.3 injectors back in as well to make sure that 5.7 are not screwing things up too badly by dumping tons of fuel.

[crash8212]

Ok guys, I think I might have found ONE of the significant problems I had with the fuel system. I went to the salvage yard Saturday and picked up a set of injectors. The guy at the counter gave me the whole injector manifold instead of just the injectors themselves. I tore into it this morning and looked at the brass seat on the pressure regulator and noticed it was MELTED to the body and stuck halfway open. I swapped it out with the one from the scrap yard (lucky they went the route of giving me the whole assy) and it made a HUGE MONSTROUS difference. Now, it still stumbles and goes a little flat at WOT but that is because it still has the 5.7L injectors. Thats right, they gave me 5.7L injectors. I neglected to check the color code before I left the yard and I just trusted a scrap yard dogs word OOOOPS! So I logged a little more data and will be throwing 4.3L injectors back in sometime this week. Can't do it today as they are all closed or I would be.

Im attaching the data in case anyone cares to view. I am showing a problem with my O2 sensor reading. I just ordered a 3-wire and will be doing the conversion when it arrives but it will be a few days.

The BLMS and INT look to be in a better range, not perfect but that could be a combo of the O2 being bad and the 5.7L injectors either/or/and other things.

Could someone please explain the BPW HACK to me so I understand what I am looking at (or what I should ignore) when using this Tunerpro mask.

[crash8212]

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[EagleMark]

You got error codes 24, 33, 44 and 54 set so data is not good... lean all over, could be the BPW of 5.7L injectors compared to 4.3L Injectors. Also have something wrong with O2 sensor voltage as it is 4.3 Volts most of time and jumps up to 13, 17 volts? Should be 1 or below?

1 down and several to go...

[crash8212]

You got error codes 24, 33, 44 and 54 set so data is not good... lean all over, could be the BPW of 5.7L injectors compared to 4.3L Injectors. Also have something wrong with O2 sensor voltage as it is 4.3 Volts most of time and jumps up to 13, 17 volts? Should be 1 or below?

1 down and several to go...

Yes, I am aware of the problem with the O2 sensor. I ordered a new 3 wire to hopefully fix that situation but have to wait for it to arrive. The injector problem was supposed to be fixed but I was sold incorrrect parts. It is kind of odd the readings that the O2 is giving, I am hoping it is faulty and not really reporting .004 volts. Even with the poor readout, the engine ran SOOOOOO much better than before. It is always nice to make a step in the right direction

As for the errors, how do I read error codes in TPRT? I am attempting to teach myself this program but it is not entirely intuitive and has a steep learning curve IMHO.

So in short, the O2 and injector problems should be removed from the equation shortly.

[EagleMark]

Really don't need a 3 wire unless you have headers that cool off on highway etc and go open loop. You can check wires to that one, with the high spike it may be to close to a spark plug wire? I may have been messing with my adx but it said 4.3 volts which is way beyound possible unless the wire is wrong to ecm... Also just remembered from another thread in conversions if you run the EFI harness to close to spark plug wires can cause issues.

While playing back or connected to data you can use the Item List and choose Error codes in the ADX I built for $42.
http://www.gearhead-efi.com/Fuel-Inj...Information-42

If you can burn chips you can make the change in the bin file, burn chip and instaed of reading Prom ID you will get BPW and injector duty cycle and the MPG history table would work if you had a VSS, just read the instructions in the XDF file. Not really an issue for you at this point...

[PJG1173]

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Nice!

[crash8212]

New data with the correct size injectors and a new o2 sensor (3 wire without the heater hooked up yet). Haven't had a chance to review it yet but it is not running as well past 1/2 throttle as it did with the 5.7 injectors. If I slowly roll on the throttle (VERY slowly) then it will get to 3/4 throttle without bogging out but if I just press it normally it will die at 1/2 throttle.

I cleared the codes also

Old o2 sensor was definitely a junker. Getting good readings now.

Just for the hell of it I am going to throw the 5.7 injectors in to see how it reacts. Don't have an adjustable pressure regulator yet so it is all I can really try. Will post data shortly.

[EagleMark]

I've never seen BLM data change from 120 to 162 and back in same cell from one fram to next, or across board like that? Something is wrong?

[crash8212]

Yes, something WAS wrong. One injector had a bad o-ring. I replaced it and the data got a little better but overall run quality didn't improve much. I swapped the 5.7L injectors back in and WHAMMO! Its purring like a kitten. Just drove it for about 10 minutes. It runs about 90% of where I think it should be, it lacks a little throttle response from 1/2-3/4 throttle at 3000-4500 rpm but if it downshifts it comes alive.

There is a problem I definitely still have (and it is VERY odd indeed). When the fuel gauge reads 1/4 tank or lower and I take a left AND ONLY LEFT hand turn the engine will chug and/or out right die. I was logging data and it did that to me a few minutes ago. Must be a baffling problem in the fuel tank. I am posting the data but I know there were errors in it due to it dying.

[EagleMark]

I'd never expected the 5.7L injectors to run better in a 4.3L ? But the other driveability issues may be the huge difference in BPW between 4.3l bin you have and 5.7L BPW needs...

Pretty common issue with 1/4 tank and sloosh on conversion to tanks without baffles...

[EagleMark]

May run better but BLM are still strange? 108 and next to it 152 and then 114... then 108 will change to 152? I've just never seen that before...