MAF(afn?) code thrown
#1
Driver School Candidate
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MAF(afn?) code thrown
93 400, not original motor, been in limp mode since I got it. Will not go over 4500rpm and runs rich, I've been searching for answers on and off for about a year with no success so far, I need the help before I do a carnal sin and take it to a dealership. The gauge cluster did not work so I replaced it with a 92-94 sc300 cluster and everything works perfectly, replaced the MAF with a tested one and it did not fix the issue. I was told to check the driver cam sensor wire and it is in tact. Any and all help is appreciated, please and thank you.
My all stock Lexi and Subaru project in back ground<br ><br >
#2
Lexus Champion
iTrader: (10)
the sc300 cluster the rpm's wont read accurately, the tachometer is different between the I6 and the V8. there is a a chance you are actually getting higher rpm's and you just don't know it.
if it still wont get up there in rpm's though and really running rich, I would suspect the ecu needs a rebuild, but it could be lots of things.
if it still wont get up there in rpm's though and really running rich, I would suspect the ecu needs a rebuild, but it could be lots of things.
#4
Lexus Champion
iTrader: (10)
does it idle pretty low and run rough? the only other time I have heard of the tach reading low when the cluster was working is when one of the coilpacks or ignitor failed. on the sc400 failed coilpacks are very very very common. the car will still run but be sluggish cause its basically on 4 cylinders so it wont rev up all the way and the tacho reads funny cause its only getting pulses from half the ignition.
I would think its one of the coilpacks, but a bad ecu is still a possibility.
also in the 2 distributors that the coil wires are in, there is a rotor under the cap and when it gets worn you get funny ignition problems like a failed coilpacks except it will be more random the cylinders it affects.
if you unplug the coilpack with the engine off, then try and start it. if there is no difference, thats your bad coilpacks. if the car then wont start or starts alot rougher, then the coilpack was working.
I would think its one of the coilpacks, but a bad ecu is still a possibility.
also in the 2 distributors that the coil wires are in, there is a rotor under the cap and when it gets worn you get funny ignition problems like a failed coilpacks except it will be more random the cylinders it affects.
if you unplug the coilpack with the engine off, then try and start it. if there is no difference, thats your bad coilpacks. if the car then wont start or starts alot rougher, then the coilpack was working.
#5
In Recovery Mode
iTrader: (11)
^As Ali mentioned, your issue sounds like a failed coil pack. (ignition coil same thing)
When mine failed, it ran fine, (didn't stutter or backfire etc) BUT it was very low on power and raw fuel was being dumped and not being burned because one side of the V wasn't operating. It did rev high that way, however.
When mine failed, it ran fine, (didn't stutter or backfire etc) BUT it was very low on power and raw fuel was being dumped and not being burned because one side of the V wasn't operating. It did rev high that way, however.
#6
Driver School Candidate
Thread Starter
I'll be home the 3rd and 4th to fiddle with it and check out ignition side of it. Hopefully it'll fix it there before having to look at the ecu. When I first got it only the passenger side cylinders were firing, turns out a burnt wire in the drivers side was at fault. Then at idle it would go down about 200rpm and then come back after a sec, even when driving if I let off the gas i noticed it. But it's been about 4-6 months since that's happened.
#7
Lexus Champion
iTrader: (10)
it could also be the maf but its odd a tested one did not work then.
you sure you are pulling the right code though, might want to double check.
I would check the wires on the connectors for damage, sometimes they get brittle etc.. and a good maf will still not work. the mafs are known to be a problem issue on these cars. some people say the early years 92-94 you can actually just unplug the maf and it will run better, so you can give that a try also.
you sure you are pulling the right code though, might want to double check.
I would check the wires on the connectors for damage, sometimes they get brittle etc.. and a good maf will still not work. the mafs are known to be a problem issue on these cars. some people say the early years 92-94 you can actually just unplug the maf and it will run better, so you can give that a try also.
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#8
it could also be the maf but its odd a tested one did not work then.
you sure you are pulling the right code though, might want to double check.
I would check the wires on the connectors for damage, sometimes they get brittle etc.. some people say the early years 92-94 you can actually just unplug the maf and it will run better, so you can give that a try also.
you sure you are pulling the right code though, might want to double check.
I would check the wires on the connectors for damage, sometimes they get brittle etc.. some people say the early years 92-94 you can actually just unplug the maf and it will run better, so you can give that a try also.
I'm in the middle of diagnostic. When the MAF is connected I can't trust what the car will do once warm taking off from the lights. It bogs down with a weird fuel problem but can just as quickly launch like nothing is wrong.
Interesting point about brittle wires. Did check that but might revisit it.
#9
Driver School Candidate
Thread Starter
Got home early and wanted to check the codes again, after a jump wire and paper clip test, the CEL flashes once then fades to barely noticeable on the second flashes and then it's gone. I've tried both the engine and under dash spots with no difference. ***Small update, bought driver door trim, new driver control panel, and passenger taillight. Tomorrow will be new muffler, front bumper, and driver door handle.***
#11
Driver School Candidate
Thread Starter
That's the way I'm thinking too. Tomorrow is my last day home before I go back out on the road. Since I let my folks borrow it while I'm on the road I'm gonna wait till they get their car running before I put mine down for a little while. Hopefully the ECU will be the end of problems for a bit, gonna do a BFI mod on my next trip home.
#12
BTW running without the maf plugged in only lasted a few trips and now it is as bad as if it was connected.
Internals of 1UZFE ECU with stuffed leaking capacitor. Note missing surface mount resistor
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