Aristo swap giving some trouble. No codes, misfiring, more.. [Added video]

[ifyouaint1sturlast]

Ok, so..

Just completed my Aristo swap into my 90 MKIII. It starts and runs, but a few problems..

1) Sometimes when starting, the starter will struggle to continue cranking, if I let go of the key it sounds as if the engine completes the revolution (or spins backwards) .. indicating timing is off?

2) On occasion turning the key I just hear the click click and the car doesn't crank. If I keep trying it will eventually crank over.

3) Once the engine is running, it will not stay alive if I let off the gas pedal. If I just barely touch the pedal it will stay running at 800-1000.. but still has the misfire that I'm about to describe. I've narrowed this to be that the flapper valve for the ISCV *may* be installed incorrectly but I'll be checking that out tomorrow.

4) When trying to idle, the RPM fluctuates badly. It definitely has a miss. It sounds like a cammed up drag car or something. My friend seems to think it's one of the injectors not firing or something. I removed the fuel rail and placed it on rags and cranked the motor. All injectors sprayed a fine mist of fuel, it looked to be working fairly well. Something I'm concerned with is fuel pressure. I have no way to test it and my pump is running on 12v. I can't help but feel fuel pressure is way too high.


Specs:
-1990 Supra MKIII
-Aristo 2JZ-GTE
-Completely stock (440cc) fuel system on motor
-Single Walbro pump
-Motor is single turbo'd

Checked:
-Codes. No codes are stored. Just blinks forever and ever.
-TPS is checked/adjusted to TSRM
-ISCV clicks when the engine is turned off
-Couldn't find any vac leaks
-Checked/verified power/gnd of MAP sensor, all injectors, all coil packs, crank sensor and cam sensors
-Checked/verified resistance of all injectors, all coil packs, crank sensor and cam sensors
-Checked valve timing (all three sprockets at 0deg TDC, verified TDC with chopstick)
-Replaced spark plugs
-Replaced o2 sensor


Not really sure what to do next. Was going to check for IGF but if the ECU wasn't getting it the engine would stall, right? I really want to verify the waveform of the crank/cam sensors but have no access to a scope (perhaps the signal is being interrupted by bad wire extension, or extension interrupted the shielded wiring?) I was thinking next of buying some length of good shielded wiring and running new wires from those three sensors to test if it changes anything.

I feel that I'm looking so hard that I'm overlooking something. Would love everyone's input.


Any help is appreciated,
Thanks!


Video:

 

[Dirgle]

How do the wires look going to the coilpacks? Since the're located right on top of the engine the insulation has been known to breakdown and crack, especially on the earlier Aristo motors due to age. I know you said you verified the coilpacks, but I'm curious about the specific condition of the wire insulation, even under the fancy plastic wrap.

 

[ifyouaint1sturlast]

How do the wires look going to the coilpacks? Since the're located right on top of the engine the insulation has been known to breakdown and crack, especially on the earlier Aristo motors due to age. I know you said you verified the coilpacks, but I'm curious about the specific condition of the wire insulation, even under the fancy plastic wrap.

To be honest the wires are very flexible and not brittle at all.. How could I test if this is the problem? Resistance test? Added video.

Also, could the condition in the video be caused by the plugs fouling on initial startup (took a while to get the car to run this well) and now it's running like this due to that? I will pull the plugs soon and check the condition.

 

[Satan]

Check the things that don't usually trip a code... Vacuum lines, CPS connections, etc... Good luck!!

 

[ifyouaint1sturlast]

Check the things that don't usually trip a code... Vacuum lines, CPS connections, etc... Good luck!!

Thanks. Cam and crank sensor would trip a code though wouldn't it?

 

[Satan]

^Mine didn't. Had to swap/test. Replaced one (rear) CPS and all got better (seal was broke and oil in it).

 

[ifyouaint1sturlast]

^Mine didn't. Had to swap/test. Replaced one (rear) CPS and all got better (seal was broke and oil in it).

Ohh.. hmm..

 

[S.A. supra]

Both of my cps had oil in them, and my crank sensor looked like it was in bad shape. Kind has me worried. I'll be following Intrested it what it could be.

 

[ifyouaint1sturlast]

Both of my CPS had oil in them as well. Car wouldn't start at first, and threw a code (that indicated ONE of those three sensors had a short) .. I cleaned out the oil, code cleared, and she wanted to start. Still wouldn't though. Finally then replaced the crank sensor (was in really bad shape) and she starts and runs fairly reliably except for the symptoms described above (obviously)

Pretty surprised we don't have any experts chiming in here..

 

[Radial]

First of all... get more new and fresh fuel on that car, and a litle piece of alcohol to remove traces of water on the tank.... looks like it's on sparefuel on the video.

When that's said, take out your O2 sensor, and clean with water and pressurised air... when you choke a o2 very baldy, the sensor-element can somehow start to get shorted to ground thorugh the contamination, interfeering with the ECU signal. My 1J was reading 300 ohms from the sensorwire to ground before cleaning, and after cleaning, i could not read any resistance there anymore, and the engine revs smooth again.

The vacuumline for the FPR is also very important, and same with the MAP-sensor. Without vacum on MAP, engine will recieve fuel for atmospheric pressure(cruise) instead of vacuum(Idle).

If you want to check that the "code-system" is working, just disconnect the IAT-sensor for an example, and the ECU wil throw a code indicating the IAT-sensor is missing. - So the system then works just fine. it's just a system to give you information if there is a circiut-failure... if the sensor itself is just not responding correctly, you wont get any codes cause there is no circiut failure

And yes, if you have choked up the plugs, it can struggle with missfire to... and Irdrium-plugs etz are super-sensitive to this shit, so just go for standard NGK BKR6/7E's. Also important to check for debrees down in the sparplug holes... the old and crispy coilpack-clips often end up down there; placing them selves under the plugseal when you replace the plugs, and therefore starts to mess with your compression too...haha Just gotta love old engines

 

[Satan]

^^not to mention the leaked oil that builds up in there, sometimes fouling the plugs.

 

[ifyouaint1sturlast]

First of all... get more new and fresh fuel on that car, and a litle piece of alcohol to remove traces of water on the tank.... looks like it's on sparefuel on the video.

When that's said, take out your O2 sensor, and clean with water and pressurised air... when you choke a o2 very baldy, the sensor-element can somehow start to get shorted to ground thorugh the contamination, interfeering with the ECU signal. My 1J was reading 300 ohms from the sensorwire to ground before cleaning, and after cleaning, i could not read any resistance there anymore, and the engine revs smooth again.

The vacuumline for the FPR is also very important, and same with the MAP-sensor. Without vacum on MAP, engine will recieve fuel for atmospheric pressure(cruise) instead of vacuum(Idle).

If you want to check that the "code-system" is working, just disconnect the IAT-sensor for an example, and the ECU wil throw a code indicating the IAT-sensor is missing. - So the system then works just fine. it's just a system to give you information if there is a circiut-failure... if the sensor itself is just not responding correctly, you wont get any codes cause there is no circiut failure

And yes, if you have choked up the plugs, it can struggle with missfire to... and Irdrium-plugs etz are super-sensitive to this shit, so just go for standard NGK BKR6/7E's. Also important to check for debrees down in the sparplug holes... the old and crispy coilpack-clips often end up down there; placing them selves under the plugseal when you replace the plugs, and therefore starts to mess with your compression too...haha Just gotta love old engines

Great suggestions. For some reason I feel it's more complicated than any of this. However, first, I will try all of your suggestions

I have several other o2 sensors, I can just test them and swap in a good one. MAP and FPR are connected. I'm thinking maybe my MAP sensor is bad because this DOES seem like a situation where the MAP is unplugged (and it's not..)

I have checked the code system and it is working perfectly fine

The plugs I recently installed were NGK coppers, BKR7E I believe.. I need to pull them and see if they're fouled or what.

The center valley is CLEAN, no debris..

Thanks for the advice!

---------- Post added at 04:37 PM ---------- Previous post was at 04:28 PM ----------

No leaked oil either Satan, fresh rebuild on this 2JZ.

 

[ifyouaint1sturlast]

For some reason I think it's MAP or CPS related.

 

[ifyouaint1sturlast]

Just went through the harness and it looks fine other than..

For some reason, I extended both cam sensors using a four lead shielded wire. AKA, both cam sensors wires are within the same shielded insulation. Am I correct to assume that's BAD? I'm fixing it now. However, could this be causing my issues?

Thanks!

 

[S.A. supra]

I don't know if it matters, but my buddy boosted a Mazda 3. He went with a aem ecu, and his car ran like Shit. He couldnt figure it out. It ended up being a wire shield he removed. The shields purpose was to blocked out other signals and noise under the hood.

 

[ifyouaint1sturlast]

Almost done replacing it. We will see in a moment!

 

[ifyouaint1sturlast]

Did nothing. Before 'guessing' and replacing the cam sensors I will try to rewire them with completely new wiring (no splices/extensions) and see if that does anything at all. This is such an odd problem. No other takers?

 

[91TurboDave]

I had a very similar issue with my Aristo swap. It turned out that even thought the harness to the coil packs felt good it was leaking voltage to ground. I could not even see any deformation in the insulation but it had burned through and was jumping the signal to the wrong pack...it stumbled and jumped, then it would smooth out, then start doing it all over again. It was electrical signal crossover. I ended up putting in a shield sock around each pulse wire. (Yes I am an electrician) It worked like a charm. After the experiment I rebuilt the entire coil harness. Now she boosts to 15lbs all day long and purrs like a kitten...Just my 2cents

 

[S.A. supra]

Dave, do you have any pics? I just rewired my coil packs and added new clips last night. The wires were in bad shape. They were brittle and had cracks everywhere. I cut and solder them at the cam gears. Do you think that's ok?
This is what they looked like.

[/IMG]

 

[ifyouaint1sturlast]

I had a very similar issue with my Aristo swap. It turned out that even thought the harness to the coil packs felt good it was leaking voltage to ground. I could not even see any deformation in the insulation but it had burned through and was jumping the signal to the wrong pack...it stumbled and jumped, then it would smooth out, then start doing it all over again. It was electrical signal crossover. I ended up putting in a shield sock around each pulse wire. (Yes I am an electrician) It worked like a charm. After the experiment I rebuilt the entire coil harness. Now she boosts to 15lbs all day long and purrs like a kitten...Just my 2cents

Dave, that's really great info there. Did you listen to my video? Was your engine sounding like mine? That sounds plausible for my situation because like I said I feel as though the timing is off, so firing the wrong coil could definitely cause that symptom IMO.

I'll give it some consideration, thanks!!