Thursday, October 10, 2013 - 08:51 pm, by: Kev Reed(Kevjzz30)
Hey guys ive been battling with this problem for a while now and am looking for some helpful insight as to what steps to possibly take next.
Background Running a basically stock setup 1jz gte soarer 92 model, with the addition of a boost gauge and turbo timer. Car was sitting for a while before coming into my possession, previous owner cleaned fuel tank and put a new fuel filter not long before i got it.
ISSUE Car jerks and hesitates at around 2500rpm when throttle is down hard. When in gear and under load the problem is worse and basically has no power. It idles nicely in neutral and gradual acceleration will most times allow it to run through to high revs with out the hesitation. Although it will sometimes seem like it wants to stall in the lower revs around 1500rpm with light throttle.
Scan tool picks up an issue with the TPS diagnosing with live data, shows up to 50% max but generally is sitting around the low numbers and teens, when throttle is on hard. It is a known working TPS from another 1jzgte soarer. I'm leaning towards an ECU issue because of this inconsistent TPS reading. No other obvious issues come up on the scan tool. And there is no error codes.
We only recently got the scan too to work so before that we where working blind have thrown parts at the car to try make this go away and have read lots of posts on here and around the place but am almost out of ideas.
So far Replaced TPS, Spark plugs, Coilpacks, Alternator, put new fuel (as it was below 5 ltr), Checked map sensor for leaks. I would happily get a new ecu or recap the current one, but am toying with trying a new igniter also. Still feels like im shooting in the dark a bit.
Would appreciate any suggestions. Sorry if this post is a little disjointed i tried to put as much info into it as i could to help with a diagnosis. Cheers
Friday, October 11, 2013 - 07:02 am, by: Kev Reed(Kevjzz30)
OK i was planning on opening it up and looking i'll post up my results. Wish i had a spare to just chuck in and try, don't really want to buy another part and have it not fix the issue. Hopefully if the caps are bad they will stand out. Cheers
Friday, October 11, 2013 - 06:52 pm, by: Kev Reed(Kevjzz30)
So we pulled the ecu out, inside looked fine however, around the center of the pinout connector there was an oily substance. I google the pin layout and found that that area was responsible for throttle and air flow pressure, as well as some other things. This seems to all fit into place. We cleaned it up and plugged back in but the problem still persists. So my question would be, what is that oily substance, and would it be causing the above stated symptoms. Does this mean the ecu is stuffed.
Saturday, October 12, 2013 - 04:44 pm, by: Kev Reed(Kevjzz30)
Have managed to get a spare ecu hopefully to test in the car. No doubt the ecu in its current state would be causing issues. Hopefully it is the root cause, and will see the end of this problem.
This one will be up for a recap anyway.
Ill post up if this is a fix for my problems, as i'm sure someone else will encounter this again.
Probably should have pulled the ecu out sooner just to give it a look before buying other parts but there you go.
Saturday, October 12, 2013 - 06:07 pm, by: Kev Reed(Kevjzz30)
I bought the other stuff weeks ago. I meant i wish i had pulled the ecu out before i got a new tps, coilpacks etc. Guess that was the line of thinking, start with obvious reasons for a misfire... coilpacks, boost leaks etc. ecu was last in this case
Tuesday, October 29, 2013 - 08:03 pm, by: Kev Reed(Kevjzz30)
So, ive recapped my ecu. It had a blown cap, and one was starting to bulge. However after putting the ecu back in the car, my problem is now WORSE than before. It now bogs down as soon as i put down the throttle, idles rough and is kinda hunting. Also is stalling. I'm thinking that the tps needs to be re calibrated now? Nothing else has been changed other than putting a recapped ecu. The ecu was tested fine on another car. Any ideas guys?
Tuesday, October 29, 2013 - 08:06 pm, by: Kev Reed(Kevjzz30)
Also, i am thinking the oily residue on the pins was actually oil from the engine side that slowly made its way to the loom. I used contact cleaner on the loom to clean out excess oil that may have been left so that it wasn't put back onto the clean pinout of the recapped and cleaned up ecu.
Thursday, October 31, 2013 - 07:42 am, by: Kev Reed(Kevjzz30)
Tried the getting the TPS to spec using a multimeter, still no go, however i then moved on to check fuel pressure and such. Bridged FP +B, and i could feel the difference as soon as i turned the key! Started better, idled better, and NO MISFIRE. The fuel pump ECU was the problem, perhaps coupled with the main ecu needing to be recapped. Running mint now! This whole thread is just another typical example of the importance of trying easy stuff first. Probably should have done the FP +b sooner, but lesson learnt..
Peter Nitschke Junk Filterer South Australia UZZ30 UZZ31
Saturday, November 02, 2013 - 04:22 pm, by: Kev Reed(Kevjzz30)
I don't actually have a spare ECU, i just got it recapped. I tried the fp +b after that was done, so not sure if the ECU and that fluid on the pinout was effecting anything or not. I wouldn't think that it would have been helping with conductivity if it was engine oil that had made its way to the loom. The blown capacitor was associated with idle i think as well. There was a 2nd one bulging. At the end of the day i ended up with a spare tps, spare coilpacks and a recapped ecu, new spark plugs and a new fuel pump ecu. The extra bits will come in handy in the future i'm sure if i need to troubleshoot something like this again. Happy days.
Monday, November 11, 2013 - 12:49 am, by: Kev Reed(Kevjzz30)
OK so i bought a 2nd fuel pump ecu and eagerly installed it, unbridged the fp +b and the problem came back. So my issue now is what else is being bypassed with the bridge? Could it perhaps be the wiring from the fuel pump ecu? Could the EFI fuse effect it? What else is happening when the bridge is in place? Have nailed it down this far but need some more info.