NSeagle78

iTrader: (5)

My car is a SC400, 1992. I was going to take my car to the shop in the morning, but since it will not start I decided to use the paper clip and run codes. Code 31 and 32 came up (air flow meter signal). Do I need to replace that little black box that is held down by 4 phillips screws near the air filter? My car symptoms were that over months it would take 4 to 5 attempts to start. This would happen maybe 1 out of every 10 times I tried to start it and it got progressily worst. I now find myself in this situation where it now will not start. I am not over machanically inclined so answer me like you are talking to a 10 year old.

SC51

iTrader: (3)

Well if ur sure thats what it is id try
1. disconnect batt
2. unplug maf
3. take air filter/box out and inspect(clean if dirty)

4. If that dont work maft might be bad (replace)

just my 02cents

Enigma8246

you can test your MAF if you have an ohmeter. any experience with one? if not i probly won't be able to help you.

either way, if your MAF goes out you can usually still idle but very rough.

edit: also, there are multiple air sensors so it may not be the one next to your intake

sc-driver

iTrader: (7)

so what exactly happens when you try to start? Does it rev up and stall? or does it just not turn over at all?

NSeagle78

iTrader: (5)

It does both. I have now replaced plugs, wires, and rotars. My car runs fairly smooth with a air flow meter from a friend. I have my old air flow meter back on my car and it is throwing a 24 code (IAT Sensor Signal). What is that and where is it located. Pictures would be great if it is complicated. It now starts occasional after a long rest. When it does not start, it starts but dies quickly. Even if you feed it gas it still dies. Sometimes it studdles as it dies. To better answer the original question, it revs up and stalls. HELP, I need my ride.

sc-driver

iTrader: (7)

well, if it revs up and stalls, then it seems like the mass airflow sensor (maf) thats right behind the airbox.

When mine is disconnected, it'll start rev up, and just die. You should go to like an autozone and buy some maf cleaner and clean it. It might help you out. If not, then it could just mean that it went bad.

I hope I could've helped you out.

NSeagle78

iTrader: (5)

Thanks Sc I will try and get my hands on a MAF tomorrow.

Enigma8246

you may want to test first because it could be your MAF or your ICA. mine was doing that and it was just my ICA sticking. pulled the ICA off, tested it, reinstalled it and the car started right up.

NSeagle78

iTrader: (5)

Enigma8246 I used a ohm meter as you suggested and got 5 volts consistently on the harnness side but could not get any ground continuity reading from the air flow sensor side.

sc-driver

iTrader: (7)

That's because you're MAF is a karman style sensor. Here, read this about the maf sensors and look at the karman type.
http://www.autoshop101.com/forms/h34.pdf

Basically, the ecu sends a consistent 5Volts to the maf and gets "pulses" back that are grounded. So, the more pulses you get, the more air is coming in.

Sadly, you're going to need an Oscilloscope to properly test it out.

This should help you out a bit more:

NSeagle78

iTrader: (5)

Thanks to SC51, Enigma8246 and SC-driver you guys were a great help. My MAF appears to be the problem. gerri (spelling probably incorrect) came down from Atlanta and sold me a MAF for $50. Since part of my trouble shooting was Plugs, wires and distributor my car sounds great. I am totally not machanically inclined. I hope it holds up. Again thanks guys.

NSeagle78

iTrader: (5)

I thought I had fixed my problem by replaceing the MAF but I was mistaken. If I hold my mouth just right my car will start and run great. The car will not put you down from point A to B, it just can not be counted on to start every time. It idles very low. It has now started to spuddle a little bit just before it cuts off. It virtually will not start unless you give it gas and idle it up just right and then slowly lower the idle. I checked for disconnected hoses and found the hose going to the EGR VSV broken. Also I checked the EGR Valve with R-P-Q stinceled on it. I checked it the best way I knew how according to a post on the forum. I held my hand over P and R, blocking them and then blowing thru Q. I got complete resistence. I then removed my hand from both P and Q and still got complete resistence when blowing thru Q. The forum did not explain what you do after that but I think that means that part is bad. Both parts are very small and very expensive. HELP

sc-driver

iTrader: (7)

definitely dude, check all your hoses to make sure they're connected. The low idle could be the Idle Air Control Valve (IACV), check that.
https://www.clublexus.com/forums/per...rol-valve.html

I'm not quite following what you're talking about with the EGR Valve and the R-P-Q.

Hope I could help.

v8soarer91

NSeagle78 - its a Intake Air Temp sensor

NSeagle78

iTrader: (5)

Is that the same thing as the Idle Air Control Valve? If not please give me direction on how to locate it. Pictures would be great.