runs rich runs lean with a reallllyyyyy bad misfire under load
 

First off i thank everyone for the help!! Here is what i have a a 1984 fj60 landcriuser that i put a 93 tbi with a nv4500 i used a howell wiring harness and ramhorn manifolds with 2 1/2 duals all the way out and a vss sensor tire size is 35's here is what ive done and the symptoms im having.


symptoms

1. All of this started slowly this thing ran like a top for the first 4 months with no problems at all then slowly it developed this miss!!

2. hesitates/bucks/cutouts under load always in 3rd through 5th but its getting worse and now sometimes does it in 2nd

3. rpms at idle jump up and down 1 to 2 hundred rpms from time to time.

4. in the last two weeks it has developed a bad hesitation when cold when im starting out from a stop in second only does it for a few seconds!


5. I have zero error codes!!

6. All of this Except number 4 only happen when the motor is warmed up! When the motor is cold is runs pretty decent!!


Things I have done

1. replaced every sensor on the motor except the iac all of them that i bought were the top higher priced one NOT the cheapos

2. Rebuilt the tbi unit and put new injectors in it!

3. replace the entire egr setup and it works good now!

4. changed out the one wire 02 sensor for a 3 wire heated setup

5. put a inline fuel gauge in im getting 13.5 psi

6. changed the entired ignition system out(when i changed the plugs one of the electriods was burnt clean off its been fine ever since)

7. timing chain does not seem to have much slack in it

8. checked for vacuum leaks about five times now and havent found one!!

9. changed the fuel filters

Thats all i can think about right now if it helps with the data reading it was about 34 deggrees out when i did the log and it was a combo of town country and highway driving im not sure if you need the blm's if so i have those as well again thanks for all the help ive been stumped on this one for about 3 months now and its seriously driving me nuts!!!

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

Have you done a compression/leakdown check? How about ignition timing? I know the log said it was at 34 degrees SA, however if the base timing(where the dist. actually sits) is off say(-20*) then you are really only getting 14* max.

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

I have not done a compression test yet everytime i get some extra time its raining like crazy or snowing i will try to get it done today though!! so you can see where the timing is at when your looking at the log? what area is that under? 34* seems like a ton of timing to me doesnt it? it always seem to me from the sound of the motor that it is always running way to advanced! and when i set the timing with the wire unhooked to 5 then hook it back up the timing mark jumps up i would guess 20+ degrees is that right?? i know im not a tooth off on the distributor!!

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

No 34 degrees isn't to much timing, the stock timing table will put it around 34* at ~2800 rpm(depending on MAP). Looks like you set ignition timing properly with the est disconnected to 5* base, which is fine. Ignition timing at idle will be around 20* with est connected dependent on CTS(more if it's cold).

Have you read the plugs after it was acting up?

Do that hot compression check/leakdown asap!

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

i ahve not read the plugs in the last couple of weeks read them about a month ago after i changed them and they where white on one side and barely tan on the other!! iw ill get the compression check today!!! and let you know where it is!!!

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

If I'm reading the log file correctly there is no SA data. It also appears that there is continuous knock being reported. Also need to get a DRAC on the VSS so that the ECM has the correct MPH reading.

I hate these WinALDL log files as the columns don't line up with the header. Is there a way to dump it as a CSV file? Or one where the columns line up with the header?

RBob.

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

thanks alot rob for reading it!!! yes i have done it through word but then it wont load on here for some reason?? so im not real sure what SA data is and why i wouldnt have it?? whats a drac for the vss?? im going out to do a compression test now so ill be back in a bit with that info!

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

sa = spark advance , the drac is used to convert or can be used to calibrate the vss signal to the ecm. dracs are 40ppm.

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

I checked the '4288 ($A0) data stream and the SA is not in it. VSS for DRACS is 40 PPR. The DRAC will convert that signal to a 2K PPM for the ECM. They are programmable so that you can adjust for tire size and rear gear ratio.

Hey, opening the .txt file in Excel works...

RBob.

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

I had misunderstood the original post where he had mentioned 34*, i interpreted that it was 34* sa not 34* temp. Even still total timing should come out to be around 34* for the engine to run its best. I really dont think the vss has anything to do with this issue though considering that it ran good for 4 mo. before there was an issue.

Best of luck finding getting it fixed!

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

so you guys are saying my SA is not working?? i just got done with the compression test and it shows this

1,3,5,7,2,8 all show 126 4 and 6 are 124 they all seem a bit low to me! the plugs are looking like the motor is running lean to me its barely tan on one side and the other side looks like it did when i took the plug out of the box! so why are my blms running all the way up to 150 i thought that was bad??

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

As far as the compression is concerned your fine, the important thing is that the readings are close to each other, within 10% is good and yours is even closer than that.

I misread your first post, i thought you said you were getting 34* timing, not that it was 34* ambient temp. What rbob is saying is that your sa is not shown in the log, that doesnt mean its not working.

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

so where should i go from here??

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

Find out why and eliminate the knock counts. I'd bet that there is a broken bracket, exhaust rattle, loose accessory bolt, or an accessory with a bad bearing.

It is causing a lot of false knock to be reported and the ECM is pulling a lot of SA out.

RBob.

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

Did you verify TPS Volt readout is nice and smooth when you move throttle with engine off?

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

yes i have checked that it starts out at .67 volts and it says its open 3% then moves smoothly up to 4.71 volts at 97% open seemed a hair off to me but my book says its okay !!! what do you think?

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

That's not it. RBob found enough knock counts in your WInALDL log, I don't know how as it's a disaster to look through. But with that and you pulled a spark plug with an electrode gone I'd say you have a spark issue.It may be a rattle, but a spark plug electro gone points to more then a rattle causing Knock counts. Do you have the old spark plug? Use a 10x magnifying glass and look for specks on it!

You say you changed entire ignition system? Did that include distributor? Or at least pulling it for inspection and replacing the EST with a Delco unit? Quality cap and rotor? Could even be a coil issue? Check base timing and reconnect bypass and check timing advance and see where it really is.

The motor is in a 84 LandCruiser so you have ground issues not covered from factory and we don't know if they were dealt with in the conversion, where's the ECM? Any wiring for EFI near high voltage wires?

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

The data does look like a disaster i put it in word so it was all nice and clear but it wouldnt let me load it for some reason! anyways the grounds were all hooked up the exact same way as was factory!! the ecm is in my glovebox sitting on rubber mounts all wiring to it is good! no high voltage wires around it! i did change out the entire ignition system including distributor cap and rotor, coil everything!! i would like to note when i did that i bought what i thought was a good cap and rotor from orielys i thought it was good because it was expensive when i put it on the the rotor didnt fit tight!! i ran it for a few weeks like that and took it off to inspect it and i could see that the pin in the center of the cap had rounded out the contact on the rotor which leads me to believe that the rotor was wobbling around and causing my misfire! so yesturday i went to napa and got the best cap and rotor they had the rotor fit nice and snug as did the cap and now my miss is gone!!! moral of the story is im never ever buying parts from orielys ever again!!!! now it still doesnt run good at 0* but at zero i have pretty much no knock counts bump it up to 5* it runs perfect but it increases my knock counts!! so why would it not run good at 0 but run great at 5??

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

I would check compression again. Squirt oil in plug hole and see if compression changes. Did u by any chance replace head gaskets?
Do plugs on one side look like they've been steam cleaned? You say they're like new.

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

they dont look steam cleanded they just look brand new on the one side other side looks nice and tan! why would i put oil in? and no i havent changed the head gaskets!

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

Have you verified that TDC on the damper is actually the engines TDC? They do "slip" occasionally.

Re: runs rich runs lean with a reallllyyyyy bad misfire under load
 

This summer I installed a rotor cap and a ign module due to a code(EST) for ign module. Later I find out new parts neither was seated 100%. Maybe 75%. I was fearfull of over tightening. Over 500 miles they apparently loosened up. Tightened up again and all is fine.