jcs64

first off I gotta say the knowledge on this board is unreal! Ive been burning up the search engine here for weeks!
My names Jeff and I live in Amsterdam NY. I just bought a '90 jeep wrangler w/ a 350 TPI engine and a t350 tranny. Its got 3.55 gears and Im running 31" tires for the winter (2800 rpm @ 60) and 33"s for the unsnowy months (2500 rpm @ 60).

Ive already done ALOT to this set up to get it running better so Ill give you a little background to were Ive been.
First off it was running kinda bogged down and intermitantly spitting out code 44 (lean exhaust). The worst part was I only got 9.03 MPG! I did some tune up stuff, adjust TPS (.545), Timming (it seems to like 4* best, skips a little at 6) and confirm fuel pressure (34 at idle, and 42 is when I snap the throttle).
It still seemed to run like a 1970 pickup (boggish and noisy). So I take up to a buddies house to throw it on the scanner.
Pluse width 1.6
Map .o29
o2 was averaing .62
MAT 30*C
IAC .019
o2 cross counts bounced between 001-004
intergrator(or what ever that word is) avg. 130
but heres the problem spot:
BLM open loop 145
BLM closed loop 160!
These values were listed under cell 4 (we couldnt figure out how to look at the other cells)

So heres what I did, Reconfirmed the FP, retorqued both the intake and exhaust bolts (while searching for leaks, none were found), also welded up the exhaust leaks were the old owner was too lazy to weld the top of the pipes were he coulndt reach. I also threw on a new 3 wire bosch o2. Probably dont need the 3 wire since its in a stock exhaust manifold, but its done. Test drive revealed that something was done right! Performace seemed way up and it sounded soooo much better plus the code 44 never came up again! So ,I run ip to my buddies, hook up the scanner and see, open loop BLMs of 145 and closed loop BLMs of 160! Dammit, no changes from before! It must have been the exhaust leaks that were making it sound and "FEEL" so bad. So I pulled the plugs to have a look see. They were 1/2 and 1/2 white and tan.

Heres some more info that I have gatherd.
730 series ECM (reman sticker says 7-7730)
heads are #462624
cam lift is .390- .405 (pretty lame I know)
20 inches of vacuum @ idle (I would say shes pretty "stock")
I pulled the prom chip and what I found scared me. first off was a factory
#68767 01502-1
but the bad part was 3 different sets of writting on top,(4k- speed in- TPI-novats, C6 speed in) so this meens that the chip was definetly "played " w/ by who knows who.
the injectors are D1570BA which are 24lbs

Now Im stumped so I come to you guys what do I do next? Im thinking that a new chip is definetly in order but I dont know any one local that does this and a guy I found on the net needs more cam info that I cant possibly get.
Alright, let it fly, what did I miss.
Once again this site is great And I look forward to learning even more from you guys.

Eagle223usa

Did you try Alvin at PCMforless.com? He did a great job on the custom chip for my 88. Good luck bro, sounds cool!

jcs64

thanks for the tip, I checked out his online worksheet for the chip and there are some things that I wont be able to answer such as,most of the cam specs and the engines compression ratio. If I go that route Ill give him a call and see what we can do.
Does anyone here think thes BLMs could be associated w/ a badly programed chip? Seeing as though they start off at 145 in closed loop, that seems odd to me but Im still really new to all this.

brandotron

iTrader: (2)

Lets see some under hood pics!

jcs64

Not all that pretty to look at yet but things will be tidied up according to priority (#1 bieng that it runs correctly!).
Keep in mind that this is a daily driver too.


Now back to the issue.
Ive gone thru a couple tanks of gas now and my MPG is alternating between low 9's and low 11's (11.12, 9.03, 10.12, 11.25, and just today we fell back down to 9.3) I drive the same route to work everyday and at the same speed, what gives?
I was told that the High blms im getting will deffinetly give me poor MPG. (is that true?)
Any suggestions to whats the next thing to look into in hopes of solving this problem?

Thanks, jeff

jcs64

well, I got back to the scanner again last night and heres what we found.
Start it up and as soon as it goes closed loop, the blms peg at 160.
so, I hook up the fuel press reg and im reading about 32-33. I then unplug the vac line and plug the port, now were at 42-43 psi. Guess what, the BLMs start to drop! So we take it out for a ride w/ the scarnner hooked up and finally, driving conditions are having an affect on the BLM (were before it was pegged at 160 and nothing would change it). While decelerating from 60'ish the BLMs even got down to 135, but they mostly stayed around 150.

Im going to look more into the delivery system over the weekend , but the first thing will be the filter. I found that it still has the 4 cylinder jeep filter in it which #1 who knows how old it is and #2 this filter may be to restrictive to begin with.
If I were to by the camaro filter Im hoping I could get fittings to go from the flare to a hose nipple.

Any thoughts?

Street Lethal

iTrader: (16)

^ Very interesting project you got there....

joshh44

i wish i had a jeep and just blow in some mud
and having a chevy V8 under the hood to. oh man. funfunfun!!
i like your new toy lol

jcs64

Well,this post has been veiwed over 200 times and Im still hoping for a little input on this so Ill try to bump it back to the top.
I was told that this sounds like the prom is set for a bigger injector than what I really have. That would make since for the lean issue and the higher fuel presure helping.
The engine seems to be running strong now but at 9mpg I still got a problem I think.

Anybody have any ideas?