1JZ Cressida was running rough, now won't start.

[dumbass]

its been running good for awhile
so either a sensor has failed
or fuel pump
or ecu
if u get stuck i can look at it in 3 weeks if your near for a fee

[bk_]

So is it a JZX81 / JZA70 ECU (2-row connector) or not (JZZ30, JZX90 - 4-row)?

Does it run at all when cold? warm? hot? or it's a problem in all 3 (water) temperature conditions?

Might be a hole in the vacuum hose to the MAP sensor. Unlikely but possible.

Ignitor failing?

Hard to know without wideband controller, to see if it's running rich or lean.

Got a boost gauge or boost controller? Do you know what vacuum it idles at?

[phoenixbaron]

Fuel pressure is good so I doubt it is the fuel pump..
When the car does run, disconnecting the MAP sensor, crank sensor or cam sensor causes the car to stall instantly, so I think I can rule that out also.
I'm gonna say plugs, coils or ECU at this stage. Oxygen sensor or catalytic converter are also possibilities I think.
Thanks for the offer of help, but I live near Cairns.

[phoenixbaron]

So today I replaced the coil packs and still have the same problem. Have taken out the ECU and there does appear to be something leaked in there.

Would you say this could cause the engine to randomly miss on cylinder 4 and randomly not start?

[bk_]

So today I replaced the coil packs and still have the same problem. Have taken out the ECU and there does appear to be something leaked in there.

Would you say this could cause the engine to randomly miss on cylinder 4 and randomly not start?

Sure, that's the infamous capacitor leak issue. It can also corrode / destroy some of the PCB tracks, too.

I'll presume this is a JZA81/JZA70 ECU because i've never seen this issue on the 4-row ECU (JZZ30 / JZX90).

[phoenixbaron]

I am pretty sure it is a JZX90 ECU. How can I tell for sure?

[bk_]

I am pretty sure it is a JZX90 ECU. How can I tell for sure?

4-row 4-piece connector/plug, 100 pins == JZX90/JZZ30

2-row 4-piece connector/plug, 76 pins == JZA70/JZX81

[harolto]

had a problem with over fueling in my old JZA70 1j powered Cressida, ended up being the temp sender

[dumbass]

looking at that pic that ecu is only good as a paper weight

[phoenixbaron]

ok, it is definitely a 4-row then.

hahaha, I needed a new paperweight anyway.

thanks again for all your help. will keep you informed of my progress.

[bk_]

Surprised the 4-row version eventually failed.

Then again... electrolytic capacitors are only rated to last between 10 and 20 years.

[dnegative]

ECU is fucked lol
Try a good one

[Daddio]

Surprised the 4-row version eventually failed.

Then again... electrolytic capacitors are only rated to last between 10 and 20 years.

Disagree...25-50 years provided they are correctly made. Bear in mind the inferior quality of the period...

[phoenixbaron]

OK, I finally received my replacement ECU and the car now runs better than it has in a very long time. The only problem I am now having is the speedo doesn't work. It is a M/T ECU which replaced an A/T ECU. I believed this wouldnt matter as the car is a manual.

[big_zop]

Good to hear it all went well. Best to change the caps in the new ECU just to be sure.

Speedo has nothing to do with the change in ECU. Speed signal goes directly from the gearbox, then dash, then the ECU so start checking in that order (make sure they are plugged in properly and no breaks in the wires first)