my supra is having some issues, i took it to the shop and they said it was the mass airflow sensor so i replaced that and the car still wont start it turns over but it wont fire up. I opened the fuse box under the hood and the efi fuse was blown...is it possible that the fuel pump went out?? The shop said it pulled up a mass air flow sensor code when the did the diagnostics...any help would be appreciated.
car wont start need help.
- Thread starter abqMkIII
- Start date
Supraboy89;1045191 said:
replaced it and from what i can tell it hasn't blown yet, wouldn't an ecu problem pop up on a diagnostics test though... this is where im so confused. Maybe the Mas airflow sensor i bought is just bad as well, which would really piss me off cause i paid a hundred and fifteen dollars for it. and i mean i know thats cheaper then buying a new one but it should have worked.
I've worked with the mass air before alot. Mine went bad and the engine WILL run like crap - black smoke and stinky. Don't run it like that or your catalytics will get torn up fast. First place is check that ground wiring. Run a ground wire with alligator clips up to the coil pack and ground that on the battery. Have you check for a spark ?
Maybe the fuel pump is bad ? Someone here should have tips for that. See what else is on that circuit for the fuse that blew. If I was feeling real lazy I would spray some starting fluid sparingly in the throat and see if it kicks.
The ECM's on the supra are pretty tough. Do a diagnostic reading. If its giving you feedback then thats a good sign. I had a mitsubishi that would give a Mass air error code when it was time to put a new air filter on. My supra gave me mass air errors when it went (I think that damn K&N oil on the filter and plan to take it apart with pics for this site soon)
Maybe the fuel pump is bad ? Someone here should have tips for that. See what else is on that circuit for the fuse that blew. If I was feeling real lazy I would spray some starting fluid sparingly in the throat and see if it kicks.
The ECM's on the supra are pretty tough. Do a diagnostic reading. If its giving you feedback then thats a good sign. I had a mitsubishi that would give a Mass air error code when it was time to put a new air filter on. My supra gave me mass air errors when it went (I think that damn K&N oil on the filter and plan to take it apart with pics for this site soon)
89TargaT;1045292 said:
Let's qualify this statement by adding that this is NOT the case with a N/A.
Lets further qualify that by saying on a GTE it won't run like shit. It'll run fine. Just won't go over 3000 rpm. If it does otherwise something else is wrong, most probably the TPS. Not to mention he didn't specify which "mass flow" (the engine doesn't have a MAF) code he got.
89TargaT;1045292 said:
i haven't pulled them myself yet and i didnt think it will run without the afm i know my 85 toyota pickup didn't as soon as you un hook it it would die. i will look into all of the above when i have time thanks so far guys keep throwing ideas at me.
abqMkIII;1045299 said:
Let's qualify this by adding that your '85 pickup ran a VAF, same as the 7M-GE. :naughty:
CRE;1045302 said:
ok this i agree with, but at the same time when you go to purchase one for that truck it is a MASS airflow sensor, and also they are both have a plug of sorts on them that supplies both readings to the ecm and power to the maf, so yes they are different but at the same time i am confused as to why the turbo cars will run without it but the naturally aspirated will not. it doesn't make sense to me just cause they both do the same thing ideally i mean correct me if im wrong.
Because in N/A engines the AFM has a switch that controls the fuel pump. In the turbo it's done by the computer.
Btw it's not possible for a bad AFM to blow the EFI fuse. You need to look elsewhere if that happens again. A common cause is melted O2 sensor wiring.
Btw it's not possible for a bad AFM to blow the EFI fuse. You need to look elsewhere if that happens again. A common cause is melted O2 sensor wiring.
jetjock;1045333 said:
AHH makes sense now thank you for explaining that. Will a melted o2 sensor wire cause the car not to run?
No, but it could blow your EFI fuse and that'll cause the car not to run.
If the engine cranks but won't start check for spark, fuel, and codes. Unplug any sensor you think is bad. The ECU will switch to a backup mode and can run the engine off of it. Sometimes not well depending on the sensor but it will run.
You still haven't said what code they found. The AFM has more than one. If you can't remember the code unplug the EFI fuse for 30 seconds, replace it, crank the engine, then check for new codes. That said most of the time the EFI system isn't at fault in a no start situation.
If the engine cranks but won't start check for spark, fuel, and codes. Unplug any sensor you think is bad. The ECU will switch to a backup mode and can run the engine off of it. Sometimes not well depending on the sensor but it will run.
You still haven't said what code they found. The AFM has more than one. If you can't remember the code unplug the EFI fuse for 30 seconds, replace it, crank the engine, then check for new codes. That said most of the time the EFI system isn't at fault in a no start situation.
jetjock;1045341 said:
They just told me it popped a mass airflow sensor code so i figured that meant replace it. obviously wrong. i will un plug it and see if it runs, if it does i will have to talk to the guy i got the new maf sensor from. what do i have to do to be able to get the codes myself i know on my toyota truck i had to jumper a plug and it would give me them through the check engine light
It's the same on this car. Jumper T and E1 in the diagnostic block under the hood and count the light flashes. It's all in the online service manual....stop waving that spoon at me
jetjock;1045351 said:It's the same on this car. Jumper T and E1 in the diagnostic block under the hood and count the light flashes. It's all in the online service manual....stop waving that spoon at me
Let me clarify that "SST" in the manual is a 'special tool'. I use a paper clip and put the ends in the terminal as instructed. On mine the plug diagram with E1 etc is on the cover when you open it.
abqMkIII;1045373 said:
Here's general engine wont start troubleshooting:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=EM&P=4
and here is the section where the codes begin:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=23
Hey notice nothing about a failed Mass air - only "air slipping in between mass air and engine"