[CSquared]

Car ran great the first weekend I got it up and when I took it out the next weekend I started having these limp mode type issues that are driving me crazy. The car idles sub 10 afr like a bag of balls and hesitates to rev. (Aristo swap, single turbo , stock fuel aside from a SAFC and no check engine light). Tried a 2nd ecu, replaced map sensor and bunch of other little things but nothing has worked.

After catching another thread I decided to test my coil packs by unplugging them one at a time. Here were the results numbered from the front of the engine bay to the rear:

Unplug coil 1: Car runs shitty(er) and immediatly runs better when plugged back in.
Unplug coil 2: Car runs shitty(er) and immediatly runs better when plugged back in.
Unplug coil 3: Car runs shitty(er) and immediatly runs better when plugged back in.
Unplug coil 4: Made no difference in how shitty the car was running.
Unplug coil 5: Made no difference in how shitty the car was running.
Unplug coil 6: Made no difference in how shitty the car was running.

Then I decided for the hell of it to unplug 4, 5 & 6 at the same time which stalled the car immediately upon startup. Then any combination such as 4-5, 4-6, or 5-6 made the car stall just the same. THEN I tested each cylinder for spark and there is good spark on every cylinder.

WTF is wrong with my car? I am tired of spending money chasing this issue around.

---------- Post added at 04:48 PM ---------- Previous post was at 04:40 PM ----------

On a side note the nice folks who did my harness suggested a general grounding or specific coil pack grounding issue. The 2jz coils are grounded to the engine I assume being bolted to the head?

Also where did you guys do your engine grounds. I'm sure I'll miss one or two that I have but these are mine:
1. Firewall to rear coil pack
2. Firewall to rear tow hook
3. battery to body
4. bellhousing to body
5. tranny to trannymount/body

I can't find a good place to bolt directly to the head.

 

[Slow_Sc3]

check coils with a multimeter and see what ohms you get... also sounds like your wiring might be messed up.

 

[CSquared]

Yeah I guess ill be making a trip to home depot this weekend. The car was running correctly for a few days so I can't imagine anything was wired straight up wrong. I was really hoping this would narrow down my issue.

 

[Kruso]

Its a bad ECU. Aristo ECU's are notorious for this. I bet its your injectors that aren't firing correctly.

Kruso

 

[CSquared]

Yeah I sent my ECU to driftmotion to replace all the capacitors hoping it would clear up the issue with no luck... and I'm still not convinced the ECU isn't my issue (I REALLY wish I had AEM money).

Anyway... I picked up a cheap map sensor to try that out before I ditch the ECU but I'll post up for one today because this car is going on 2 years off the road officially.

 

[Kruso]

My money is still on a bad ECU. Anyone you can swap with for testing purposes?

 

[CSquared]

Unfortunately i don't know any supra guys in my area. But If I pick one up for a reasonable price i guess I can turn it around without too much loss in the end if mine is ok. None the less ill wait for the weekend to test map and pheonix tuning (did my harness) suggested grounds.

 

[CSquared]

Ok so tried a different ecu and different map sensor... Same old shit. Going to redo grounds tomorrow.

 

[Kruso]

That sucks man... have you checked to see if its possibly the coils by swapping the fronts to back and see if the problem migrates? Or possibly clogged injectors?

 

[CSquared]

Well I pulled the 3 & 4 coil assembly and 180'd it to see if it would change the conditions between the two cylinders but it did not... Injectors are in the back of my mind as well but they were cleaned and flow tested before install and worked perfectly. I swear every time I have an issue it's never the easy "oh it's definitely your ecu". It's always the oddball no one has every heard of issue. ha.

 

[super.secret.supra.club]

how is the car when you drive ir around. is it always sub or par 10 afr or does it change if your cruising highway speeds

 

[CSquared]

I haven't gone beyond my neighborhood but I don't think it went above say 11ish. Its running so rich that it was driven prob 1 mile and idled for 20 min in my driveway before the plugs completely fouled. Really honestly feels like it revs half speed compared to when it was running right.

 

[CSquared]

bump.

 

[Willjs7]

Compression numbers?

 

[CSquared]

lol no idea. I really should test for compression but I just can't see it considering the car ran perfect one weekend, saw maybe 2-3 lbs of boost and 4k rpm on a 15 min test drive and sat for a week. It's at the back of my list along with wiring at the moment. I'm pulling the injectors this weekend for another clean and flow test but if one of those bastards isn't spilling fuel I guess compression test will be next.

 

[CSquared]

lol so I uninstalled the SAFC and nothing... Then I bit the bullet and checked compression and there is absolute ZERO on 4 & 6. Awesome. I am going to pull the head this week praying for valve issues.

How the hell does this thing run?