so to follow up on my questions about the driveability of my jeep, i have fuel pressure questions.

I nmade my tb adjustable years ago. i was just looking at the location of the tab after noticing that my plugs were white. the tab is on the bottom 1/4 of the adjustment slott when looking at it from the side.

Where do you think would be a great place to start with fuel pressure? Halfway on the tab or even 3/4 up the tab?

 

Hook up a fuel pressure gauge and set it to around 12 psi for starters. If you can datalog, you can output your injector pulsewidth and check to see if your going static. If so, readjust the fuel pressure to try and get more flow to keep the PWs resonable at WOT.

BTW, in closed loop there wont be any deposits on the plugs. They tend to stay very clean.

 

This is what i have figured out. The Mule definately runs lean. The new plugs confirmed this and the computer told me when i tried to get on the freeway. And that is the only time the computer tells me things, when i try to drive it, instead of babying it everywhere. if i keep the rpm's under 1500 or so she does fine. Anytime it goes under load with throttle it sounds like lean popping, but without the backfire.

So, dealing with this, and trying to work with what the computer tells me i'm a little frustrated. For some reason, maybe because i'm using the painless performance, or whatever, no computer can communicate with the Mule's. WinALDL just gives me a flashing SES light. The handheld OBD computers give me communication errors. So just dealing with pulling the codes with a paper clip in the connector and using my voltometer i have learned reasonable things.

First, i the root of problem could be in the ignition somewhere. I get no codes that nothing is incoorrectly but i am led to the distributor rpm sensor thingy inside the base.

Now, the map sensor is cool. No vacumm leaks anywhere. The EGR is connected as well as the solenoid. WT sensor is cool. TPS is right on the money with no kins anywhere in its range. And Fuel pressure is currently at 15 1/2. This does not change either while under load.

All that tells me that the injectors are not opening long enough to add more fuel while its under load. Why? And more inportantly, who tells the computer to open the injectors longer while under pedal and load?

I personally am leaning towards the thing inside of the distributor that may be sending a false signal to the computer. And is that rpm counter thing telling the computer what to in terms of pulse width?

What do you think guys? Is there a way to test the distributor or should i be leaning towards the MAP sensor? Which i might add is located in the passenger compartment with a 3 1/3 vacumm hose?

 

Do you have a laptop and can you datalog? WinALDL and the single transister homemade cable are the way to go. The only other way to verify the AFRs without a wideband is to do a WOT run and read the plugs afterward. Thats teh only way youll get any meaning out of the deposits.

The reason its not giving enough fuel (or might be giving too much) is that it needs to be tuned. There is no compensation with speed density when your in power enrich so the volumetric efficiency tables and other items have to be right or the fueling will be totoally off.

 

winaldl is a a dream for me. i have the cable, softeware and laptop. No workie though, just rapidly flashing ses light.

I just tested the map sensor. all good. the pick-up coil, ignition coil, and ignition module. All good.

The injector pulse width is still not wide enough. I'm currently checking the brake switch relay to make sure the torque converter is not engaging all the time. Which just turnred out to be hooked backwards, but made no difference when hooked up correctly.

i am stumped.

 

now we almost have winaldl working. i get 255 in the mw2 line and that is it, no ohter data.

the fuel spray is good while revving. cannot check it while driving. the pressure stays up while driving though.

a mechanic friend proposed an interesting theory. he said that one of his customer with the same motor combo in a suburb had the same problem because he was running without cats and just dumps on his mufflers. i happen to be running headers straight back to flowmasters and dumps with no cats. Do you think that backpressure is too low and giving me that code 44? i would think that backpressure is higher when you are at higher rpm's, which negate that theory.

still stumped and frustrated

 

fuel volume looks okay. shot some into a container.

Computer and electronic spark control module were replaced today with no luck.

checked the map again, still no change. works like a charm.

eventually responded to my own posts will lead me to the cause of my problem.

i'm pulling the O2 sensor next to see what it looks like.

 

Code 44 means that youre lean. The O2 is likely working if it throws a 44. The only other possible cause is a short to ground in the O2 wire. From this, Id say it would be in your best interest to get the scan tool working and see whats going on before you continue to use the vehicle. Odds are it may just be way out of tune and you may also have too small of an injector.

About the flashing SES, what does it do? Is it a rapid flashing? How do you have it hooked up? Do you have anything in the ALDL along with the cable?

As far as the exhaust goes, this will cause you to lean out if you improve the flow of the exhaust. The engines volumetric efficiency will increase and the required fuel will also increase. But, the computer has no way of knowing this when its in open loop or at WOT, so itll still deliver the same ammount of fuel, causing the motor to lean out.

 

honestly i'm not sure if i put the transistor on the right way. i know which is the base but i cannot figure out which is the emmiter and the collector.

while it was hooked up earlier and and i was getting that one reading, the idle jumped up as soon as i plugged in the harness. the winaldl website states that will hapen if i put a 10k resistor across. wierd huh? Also have 3 laptops working against me . the brand spanking new one does not have db9 connector on the back, nor does mine. this has lead me to my sisters, which does have the right connector but no battery life. Mine just happened to completely die today too, right after i installed the new hard drive inside.

I just can't win.

Back to the real problem. i discovered while romping it in reverse that a surge occured and it actually took off like it should. Has not done this going forward yet though. I'm going to check for vacuum leaks with some carb cleaner next. It seems wierd that only goes awry under throtle. i would assume a vacuum leak would also occur at idle. Unless it is at the base of the egr valve, which feels higher vacuum with rpm's. The egr is has never function properly to me anyway. if have always had the solenoid disconnected.

Egr test is next. when i apply vacuum, should it hold the vacumm until i release it?

 

Yes, the EGR valve should hold the vacuum.

 

Sounds like you may be chasing phantom problems. Id get the ALDL to work first. Theres no need for any resisters or anything like that in the ALDL conenctor. Also, you might just want to go out and get another transistor from radioshack or something so you know what is the collector, base and emmiter. Also make sure you get the proper type. As for the laptop, many laptops will accept the +14.5 volts or so from the cig. lighter. The only special consideration is the fact that the power is 'dirty'. The manufacturer of the laptop may make a car adaptor with power conditioning circuitry built in.

 

we are struggling with the connector. i sometimes get data, but it is flashing red instead of green. can i use a 25 pin connector instead? i saw it searching but found no directions.

 

Which pin is the serial data line in the ALDL hooked up to? It should be pin A8 on the ECM. The ecm always transmits data so as long as the ALDL cable is good youll get useful data out of it.

 

it is correct. i think it is my cable. i'm going to make a new one in a little while.

Right now i'm going thru all of the indicator wires and hooking up the lights. i'm stuck on the alternator light. it has brown wire and a pink /black stripe going to the internal voltage regulator. someone remind if the brown wire has to have power from the fuse box to operate the voltage regulator. i know the pink wire goes to a power source with all the other pink/black stripe wires in the harness.

 

i was just reminded of a time when the alternator was out and having the same problem. the only difference is that i have a fully charged battery and maybe only a hour of drive time total since the two day trickle charge.

 

had the alternator tested. no luck there.

still no luck luck with the cable either. going to work on that one some more tonight.

i have had my voltometer and vacuum gauge hooked up to the map sensor this whole time. when i get into the throttle were i hear lean popping, the voltage on the map is only at 3 volts. you guys think this might be too low?

 

cable still not working. still getting the lean code when i get on the freeway. it feels like it is running out of gas on the freeway. no power, just ugly sound from the muffler. and i still have the fuel pressure maxed out with only 2 degees of timing.

i had my exhaust checked out and the dumps were leaking pretty bad so i had them welded.

i replaced the spark plug wires and that seemed to make a difference in the posiive direction. it romps around beter at lower rpm's.

checking the o2 sensor next for voltage readings while i drive around.

 

i had the lean code first few miles i would drive on first modded set up. was not surprised at all. totally expected. this was daily driving not WOT. BTW what ECU are you running? it would appear the most important thing is to get winALDL working or you will be in the dark. i bought my connector from custoimefis.com. seemed to work well. as far as the "new" laptop i used a adapter serial to USB from Radio Shack. i assume the newer laptop is USB. it too worked well. i would temporarily consider running the laptop direct to house current and log idle and off idle in neutral in driveway until the laptop with battery back up is workable. if you verify lean at idle and off idle higher rpms you could consider tuning the VE tables(globally) and correct BPW as well. that is a starting point in tuning.

 

awesome ronny. you are reading this right all of this right on. i saw that same usb connector at radio shack. instead of spending 40 bones i spent 7 on the adapter to convert to 25 pin on my laptop. still no reading. my sisters laptop is back on the way here now. i do have to admit after looking at the pics and diagrams a 1000 times over the last five days, i realized i was connecting to the wrong pins on the car computer. i was using a and b instead of a and e. its what what happens when you are in the driveway until 3 every night. what is strange is that i was getting partial bits of info when it was connected wrong. i'm still making a new cable tonight.

I'm running the 7747 ecu. have two now. Which threw a new code today, the good ol' 42 for the ignition module. Which by the way was tested yesterday at the zone and came out fine.

My motor mods are just very free flowing exhaust and a crane compucam. The MSD broke. And i did do the TBI ultimate mods. So for tuning, i set the timing to 4 degrees and brought the fuel pressure back down. I then reset the detent cable which pulled to a different location entirely. i'm really interested to see where it will shift now. oh and i replaced my MSD wires today and noticed an immiediate difference in performance in the right direction.

i will post again soon. thanks for the reply Ronny

 

module checked out okay. So did the old modules i had for my camaro. scored the other laptop so i'm looking at taking a shot at the titile again with winaldl. wish me luck

 

make certain the com ports align. winALDL-RS adapter-laptop.