Hey Guys,
Got my 1J in finally and it starts. It's on a 1988 Supra. Only thing is that it runs rough and barely runs at all. It would start sometimes and rev real rough then die out. Or it would rev up to 2k then just die out completely. It also backfires sometimes from the throttle body...sounds like a hissing or blowoff valve sound when it backfires. I do smell alot of fuel. Could it be leaking? Would leaking fuel cause all this?
Checked the timing, and it is dead on. Checked coil pack wires and cam sensor wires for juice and continuity from ECU and it passed.
I exchanged coil packs, ignitor, map sensor, ECU and it is none of those.
It does show a code 41(bad tps, or circuit) because my check engine light is on. I play with the TPS and it does nothing. I also unplugged the TPS and it also does nothing. I have asked a friend to unplug his TPS from his 1J and it runs smooth during idle like nothing was unplugged. So I am left with a bad running 1J. Could anyone know what this could be?
suprastanger507mgte: Post #4
Here's a background of what has been done so far :
First, there are no engine mods.
Wires extended and plugs re-pinned for body harness -
ECU harness - extended wire for wire and conitnuity tested for each and everyone.
Body plugs - done according to diagrams for the pre 89 Supras/1JZ mapping and all checks out. Same and similar to mine as far as power and signal wires goes.
All of the things below tested with working items:
Replaced coil packs - no change
Checked ignitor - no change
Checked Map sensor - no change
ECU checked with a known good one - no change
All of the above works in another 1JZ car so is not a problem.
TPS was set before starting engine according to TSRM
Ignitor , ECU , Coil packs all get approximately 13 volts +/- when engine key is on.
Power at EA2 connector checks out as well.
Timing is spot on as Romeo stated and we rechecked it.
There is continuity up to the ecu from all the sensors - Cams/Crank etc.
There is fuel coming to the injectors and firing for sure.
Car starts, but idles very rough and won't stay on for too long. It has loping idle and can't rev and will back fire occasionaly when it is dying.
We played with moving the TPS around and no change noticed.
Checked for code and we got only code 41 = TPS.
Will a bad TPS make the car act this bad? It was unplugged and we noticed nothing.
PS :
ECU was redone with new caps by Aaron from DM - another ecu we tried does the same thing.
Any other suggestions ? We need to get Romeo on the road quick
Got my 1J in finally and it starts. It's on a 1988 Supra. Only thing is that it runs rough and barely runs at all. It would start sometimes and rev real rough then die out. Or it would rev up to 2k then just die out completely. It also backfires sometimes from the throttle body...sounds like a hissing or blowoff valve sound when it backfires. I do smell alot of fuel. Could it be leaking? Would leaking fuel cause all this?
Checked the timing, and it is dead on. Checked coil pack wires and cam sensor wires for juice and continuity from ECU and it passed.
I exchanged coil packs, ignitor, map sensor, ECU and it is none of those.
It does show a code 41(bad tps, or circuit) because my check engine light is on. I play with the TPS and it does nothing. I also unplugged the TPS and it also does nothing. I have asked a friend to unplug his TPS from his 1J and it runs smooth during idle like nothing was unplugged. So I am left with a bad running 1J. Could anyone know what this could be?
suprastanger507mgte: Post #4
Here's a background of what has been done so far :
First, there are no engine mods.
Wires extended and plugs re-pinned for body harness -
ECU harness - extended wire for wire and conitnuity tested for each and everyone.
Body plugs - done according to diagrams for the pre 89 Supras/1JZ mapping and all checks out. Same and similar to mine as far as power and signal wires goes.
All of the things below tested with working items:
Replaced coil packs - no change
Checked ignitor - no change
Checked Map sensor - no change
ECU checked with a known good one - no change
All of the above works in another 1JZ car so is not a problem.
TPS was set before starting engine according to TSRM
Ignitor , ECU , Coil packs all get approximately 13 volts +/- when engine key is on.
Power at EA2 connector checks out as well.
Timing is spot on as Romeo stated and we rechecked it.
There is continuity up to the ecu from all the sensors - Cams/Crank etc.
There is fuel coming to the injectors and firing for sure.
Car starts, but idles very rough and won't stay on for too long. It has loping idle and can't rev and will back fire occasionaly when it is dying.
We played with moving the TPS around and no change noticed.
Checked for code and we got only code 41 = TPS.
Will a bad TPS make the car act this bad? It was unplugged and we noticed nothing.
PS :
ECU was redone with new caps by Aaron from DM - another ecu we tried does the same thing.
Any other suggestions ? We need to get Romeo on the road quick
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