MikeFig82

iTrader: (13)

I have a 98 GS400 with serious throttle lag for the last couple of months. I have tried 3 MAF sensors that all read about 1.77 to 2.12 K ohms when checking with FLUKE meter. 1 is brand new OEM and 2 are used. Can they all really be bad MAF's? I've also bought one from Sewell a few months back and it measured the same reading and the car ran horrible so I returned it. Also I've tried each one and reset ecu the car runs different on each one, but once the car is reaching operating temp the car just falls flat on accelerating and stumbles.

Thanks in Advanced

STREETGS

When u say u bought one oem, u bought it directly from the dealer?

MikeFig82

iTrader: (13)

Yes I've bought one from Sewell and one from ebay Toyota oem

And I had 2 used ones also OEM that I got my hands on.

MrHimbert

You can get it started though right? Throttle lag ? I doubt it's your MAF. Look into the throttle body area. Many of us have experienced the same thing as you.

MikeFig82

iTrader: (13)

Yes I just feel the car is bogging at low rpms, and when I try to floor it it stumbles really bad. I feel as soon as the car starts to warm up in the mornings. I can feel like if the car is dragging or I'm towing a trailer. I've pretty much changed all major sensors. ECT, MAF, O2 sensors all 4, New Cats with custom 2.25 pipes to borla XS mufflers. I have no CE light. I've done Trans drains and new diff oil changes too. TPS has been changed new fuel pump, regulator, and filters. I also have a K&N intake too. The plugs are new OEM Denso. I've had some spare throttle body parts and switched them out before made no difference on the issue.

Last night I drove the car in M mode and pwr mode. The car ran awesome and strong. Then this morning pretty much the same as before starts lagging on acceleration. I almost feel like the temperate oustide at times affects the cars performance.

Need4Speed

Doubt its a MAF at this point.

What are the odds of two bad MAFS

MrHimbert

Of course outside temp matters. If it's too hot your car is probably undergoing heat soak from the intake bringing in higher temps than we would like. Cold air is much better for a car than hot air.

My car is very similar to yours in terms of signs and how it's running. Unplug all the sensors along with the negative terminal on your battery. Take rubbing Alcohol in a spray bottle or electronics cleaner. Spray the sensors and plugs. It will evaporate so don't worry. Keep that terminal off on your battery for at least 20mins. Plug everything back in, then put the negative terminal back on. Start it, let it run till normal temps. Keep an eye on the RPGs and report back. Sometimes a little reseat does the trick.

Check for any loose wires as well. Give them a slight tug to make sure they are snug. Not too hard though.

MikeFig82

iTrader: (13)

The reason for this is that all 4 MAF's I have. They don't check out within spec of the test procedure. 2.21 - 2.69 k ohms @ 68 F. I've looked at some other CL tread and he clearly shows 2.59 k ohms readings while testing his MAF. Mine all test at 1.79 to 2.11 or so. I can't get one to show within specs with a multimeter.

MrHimbert

You must isolate it first before you make assumptions. Not hating, just being real. Check the wires going to and from the maf if possible. Could have a short. Sometimes things malfunction yet pass certain ecu tests and will show no codes. Just brainstorming.

MikeFig82

iTrader: (13)

Thanks for your replies awesome feedback. But in my case I've done this about 10 times reset ECU traced MAF wires re traced my steps. On all the stuff I've changed out on TB.

So at this point I'm stumped. I've got an obd2 scanner recently. I've been messing with it as for I don't have much experience reading the data. Besides that the car feels like it runs good when it wants to.

MrHimbert

Hopefully it is a nice one! The cheap ones that can only read and erase codes aren't that helpful in these gremlin type of malfunctions

MikeFig82

iTrader: (13)

I have a Actron cp9580

MrHimbert

Oh damn. Start exploring! There is so much you can do on the nicer ones.

STREETGS

I had the same thing happen to me and it was the maf sensor i tried 3 different ones and nothing, once i took it to a shop they said i needed a new maf, i didnt tell them i had already bought 3, the one they replaced fixed the problem,

have you checked your, throttle position sensor
/

STREETGS

What u can do is just take it to a shop, they will call you and tell you what u need to replace, if its a part u can do yourself then just pay the shop for the diagnosis and do it yourself.