Air Flow Meter???

As you can tell, this car is turning into quiet a project . . .

One of the problems has been an interment cutting out. I can warm it up in the morning, drive it 30 minutes to work. 20 minutes later drive it and it starts this cutting out scenario.

This morning I drove to work, then to a mechanic. He replaced a more than likely non-essential part, one I had asked about earlier, (BVSC). I mentioned about the cutting out. When the part was installed I started the engine and it was sitting there idling just fine, then all of a sudden . . . thud . . . it just cuts out, began stuttering around then finally died.

He checked the fuel pump and for fire. Both were fine. Finally the shop owner came over and mentioned it was probably the Air Flow Meter.

Any insights???!!!???

Thanks.

Did you pull the engine error codes yet? I remeber saying to you that those will tell you exactly what is wrong electrical/mechanical wise with the car, i.e. the MAF if that's what it is. Just for fun jiggle the MAF wiring connector, it doesn't happen that much on n/a's but on turbo's the heat caused by the turbo cooks the wiring, more often the CPS and AFM wiring causing temporary cutouts in the circuit every now and then. By the way does it only cutout when the car is good and warmed up? After it cuts out and eventually dies can you start it back up? Then you have to wait 30 minutes or so to start it again? If so that's the exact symptoms of a bad ignitor/coil, when the coil heats up the wiring expands and breaks the circuit causing the seriious loss of spark. I got mine from autozone for like $40, Toyota wanted $100+ IIRC

When the guy jiggled the connector it died immediately . . . a couple of times. Then he would wiggle it around with no symptoms. He sprayed some contact cleaner, but said the problem is probably in there. Nevertheless, what you said is right. When cold and driven it runs great, but when warmed up it seems to do its malfunction thing.

Thanks again. What does the air flow meter cost?

About the codes . . . the check engine light is not on and everybody had told me it has to be on to check the codes . . . so I haven't tried it. So what . . . I will give it a shot tomorrow.

Thanks again.

If you pull the codes it will tell you if it has EVER throw a AFM code, if it is an AFM problem or AFM wiring problem you will either get a code 31 or 32. If it does exactly what I explained with the coil, that that's what it is... the coil.
EDIT: Sorry when i said EVER I mean't since the ECU was last reset (battery removal, pulling the EFI fuse), not in the lifetime.

could it be an air or boost leak? i was pretty sure mine had a boost leak and the symtoms was kinda like urs. starts but weak rpm, and may die sometimes. mines at the shop right now, but i think that since if there was a boost leak, not enough air is getting to the fuel, so its running rich. I'm no expert but just a thought.

It's a n/a, so it would be a vaccume leak. That would make it run normal at idle and like crap with any medium/heavy throttle input depending on how bad the leak is. I said what it is, if it's waiting a specific amount of time (i.e. 30 minutes or till the car electronics heat up) to start cutting out then it's got some broken wires in the coil. By the way, no the check engine light doesn't have to be on to have stored codes, it will go on when it throws a code for the first time, but goes off shortly after.

Bummer man . . . Too busy this weekend to have time to pull the codes. Hopefully I can find an evening this week to do this.

What is the idle supposed to be set at on here? I saw one place said 800 rpm, and another said 900. This is an automatic, non-turbo. And do you check in park or drive. It is set at about 850 now, but when in drive drops to 600.

Anyway, back to the coil scenario: would it do this any time (or most times) when it is warmed up, whether it is during my commute to work each day? or only when it is slightly warmed up? Like I said, in the mornings I let it warm up, drive 21 miles to town, drop my son off at school, then to the shop, with not even a sputter. I can go out 15 minutes later, or maybe even an hour later, and it acts like its got ??? :(

I'm with you, I am looking for answers in the codes first.

Thanks again . . .

Your idle is just right, it should be 750 but you can set it anywhere between 750-1000, and it should drop down once you put it in gear, since your putting a load on the engine. There is only one part that's got me thinking, your problem sounds exactly like a coil that's going out, but you say if you let it warm up first it won't do it. If it was the coil it would do it regardless of what you do, once it warmed up it would start cutting out. No problem though, I'm just trying to straighten this one out.

OK, I went out to "check the code(s)" on this here machine, and, according to the web page that you first referred to, I cannot find where to connect up to to read the codes. On the photo it shows the fuse box, and right behind it is where I would connect. On this car, the coil is perched on the fenderwell.

Go ahead, call me a wimp, but then tell me what I am looking for.

Thanks again. We're gonna win ain't we?

Under the hood right behind the fuse box, there will be a tiny diagnostics box, open the lid, and you will see a diagram on the back of the lid.. Run a sutible jumper wire from the terminal E1 to TE1, then go in the car and turn the ignition on..(dont start it) and watch your engine light flash

if it keeps flashing with the same amount of time between every flash, there are no codes..

example ( * = engine light flash)

*..*..*..*..*..*..*..*..*.. this means no codes..

*.*.*....*.* 3 flashes and then 2 flashes means code 32

and so on..

Thats how to do it on my 1990 Supra turbo anyway..

Yup you got it right, it's just behind the coil/ignitor. I keep a paperclip in my ash tray just in case, works pretty good. The flashes are alittle different though, more like dashes and dots.

OK . . . I did find the box with the terminal to do the diagnostics. Ran the codes.

Auto Transmission:

code 64 - defective lockup solenoid or short circuit-severed wire harness or short circuit.


Engine
Code 24
Code 41
Code 51

Man, reading the codes was easy, once I found the connector (laying low on the fenderwell, where it should not have been). Anyway, the diagnostic connector is now attached where it needs to go.

NOW WHAT

Code 24 - Intake Air Temp Sensor Signal
Code 41 - Throttle Position Sensor Signal
Code 51 - Switch Signal (IDL, NSW, or A/C signal sent to ECU)


Should I have cleared the diagnostic system before doing this to make sure I was getting a accurate picture of the current situation, or is this where we're at?

Thanks, yet again.

:)

when was the last time the battery was unhooked?? The ECU will hold a code until the battery is unhooked, or the fuse is taken out...

I had a very similar problem with my supra after I got the engine rebuilt..
took it to a "mechanic" and ended up spending another $2000 on parts I didnt need.. (i think he was just guessing). Found out that when they lowered the engine into the bay, it crushed a wire in the main harness...

Actually, I disconnected the battery last weekend while working on the dash, lubing the speedometer cable, so the codes are probably current.

Thanks.

If you want to clear it just pull the EFI fuse and leave it out for about 30 seconds, put it back in and start the car. The only downside to this is the ECU has to re-learn alittle bit, so your fuel ecconomy and HP will suffer for a day or two, not a big deal. After it's been running and it starts cutting out again, shut it off and pull the codes, then you will know exactly where the problem is. Since you've got 2 codes pointing to the TPS I'm going to say it's there, possibly a cracked or cut wire, or it could just be bad/out of adjustment. Do you have a multimeter you can adjust it with or test it using the TSRM numbers to see if it's ok. To check on the air intake temp code use the TSRM diagram here and a DMM.
Air Temp Sensor..
http://www.cygnusx1.net/supra/library/TSRM/fi/FI_031.html
http://www.cygnusx1.net/supra/library/TSRM/fi/FI_040.html
http://www.cygnusx1.net/supra/library/TSRM/fi/FI_032.html
Here's the TPS..
http://www.cygnusx1.net/supra/library/TSRM/fi/FI_036.html
The AFM specs if you want to ever rule that out..
http://www.cygnusx1.net/supra/library/TSRM/fi/FI_038.html
Wow that was alot of links :p