slight misfire @ 1500 rpm on light load

[japakos]

As the title says , after I changed rotor arm / distributor cap , this thing started happening. I swapped the old ones but didn't cure. Slight load/hard load doesn't matter really, as it hits 1500 rpm whatever the gear is I get a slight miss. Only there.
Any ideas? I checked the spark plugs they are good, I have TRD leads , no boost leak, no vacuum leak , TPS is ok, I even disconnected it, does the same thing.

 

[dac69er]

you have TRD leads, but how old are they? is it the full set including the king lead?

change the plugs anyway, even if you buy some cheap ones for a non turbo starlet, just to test it.

did you fit brand new rotor arm and distributor cap or used parts?

 

[japakos]

Well TRD leads are old yes they are, I just took them off a guy. Yes, brand new rotor arm and distributor cap. I think , that maybe with the new rotor arm/cap the wires got better voltage so they are damaged or something.. Any other ideas? It does it only at 1500 and only there. Other than that pulls hard no problems

 

[dac69er]

Will likely get worse.
I would replace the leads and see how you go from there

 

[japakos]

I also noticed that maybe sometimes I get a miss while on idle. When that happens, my rpms reading is weird , not all over the place but it's kind of stop at let's say 900 rpm and pick up again but you can see the delay on the gauge. When the miss happens at 1500 the rpm gauge is steady. Do you think that it might has something to do with coil? I use -IG for rpm signal

 

[Nuge]

do a diagnostic to see if u get any error codes, link the terminals Te1 and E1 in the little dianostics box thing by the battery

 

[japakos]

No errors whatsoever. Only misses a bit at 1500 and only there. Other than that it drives fine

 

[japakos]

Fixed. Was the king lead. Now after a couple of days i have another problem. Please help here. I am cruising and the afrs are correct. Whenever it wants, it goes super lean an jerks. For no apparent reason. Then it might fix itself it might jerks again. This yime I changed everything. Plug wires new plugs new rotor arm new distr cap new. Wtf? For no reason I'd say that again. Cruising nicely, and all of a sudden boom super lean for a bit. The. Normal then super lean again and I mean lean like 17:1. Those are slight loads. At wot if lets say it must have 11.5 which it does , all of a sudden boom 13.2. Wtf in this now?

 

[dac69er]

do you have a new fuel pump? if its an old tired one it could be that. also check the voltage to your fuel pump.

 

[japakos]

Well it's a walbro have it for a year or so. Here is the thing I noticed. Last night I went out to tune the car with emanage. The car run awesome and I mean spot on. So after 60-70 miles we called it a day and went home. The car was fine. Today morning it started this shit...
Oh compression is good, pvc valve is good, lamda sensor is good, tps is good etc etc. Just can't figure it out. Now it goes lean transitioning from vacuum to boost 16.9-18.0 , for a moment, then it's ok. After 10 minutes of correct afr's , there you go, lean all over the place. Slight load , vacuum (not boost) 16-17, let go the gas it might do it, it might not. CLUELESS!

 

[dac69er]

i had a walbro go bad after a year

if its not too much hassle i would try and run it on the standard ecu to see if the emanage is causing an issue

 

[japakos]

I think I might try the pump first. I had a no start issue 3-4 times but didn't pay much attention. And I have a strange whining noise since day one which goes away after 10-15 mins. The pump was used when I got it.. say.. could it be it? Maybe after a good rape last night it went? lol
PS. It's a walbro 192 not 255 and last night the tune was with a brand new tongs hybrid and autobahn manifold. Maybe this tune fooked her

 

[dac69er]

if its second hand you have no idea how long it was really used for. it could have been run dry. sounds like mine when it was dying, it starting making loud whiney noises.

get it changed and stick a 255 in there

 

[japakos]

Will try some oem first to see if that's the case. I won't boost or anything . I believe it will show me if that's the problem.
I got a 192 because I thought 255 would be overkill for the 4efte. Wouldn't it?

 

[dac69er]

It probably is, but the 255 tends to be easier and sometimes cheaper anyway

 

[japakos]

ordered an AEM 320 lt/h. Now I have a question. I installed an oem fuel pump , not fancy high pressure etc, the thing is that the whole map is lean now, not 17 and going up and down but I get 14-15 everywhere and sometimes it struggles to get 12. Is this normal?

 

[japakos]

UPDATE
oh my god.. It appears that for some reason it was the tune.. I have some minus values in the map table which when I was tuning the car seemed right. For no apparent reason the ecu didn't like them and now leans the whole thing instead of doing what is told. I put 0 values to the minus cells and the car drives fine. no chokes, no lean spots no nothing. Damn.. and I have completely destroyed the fuel pump (screwdrived it lol) and the fuel pump assembly.Well done japakos.. well done.
Not only I wasted money for a new pump, I even destroyed my old one and now retune.. Fooooook!

 

[dac69er]

why did you screwdriver the old pump?

always a good idea to have a decent pump on there anyway for piece of mind. if its been making noises etc you never know when it might die on you!


at least you found the issue anyway.

 

[japakos]

It just wouldn't come off so I hammered it with a screwdriver and the screwdriver went all the way in. Lol anyway I should change it any way as it was making noises. I hope that problem will be solved with the aem and a new tune