Electronic Mass Air Flow Sensor

electronics gurus here might point me in the right direction with this.

from a 1990 Mitsubishi Eclipse (same as Eagle Talon, Plymouth Laser). This one's DOHC non-turbo.

for less than $200?

Jesus, guess I am in the wrong market.. I bet I could repair one of those.

It seems anything electronic on a car these days gets a large price tag.

I recently converted a diesel fuel control module that mounts on the engine over to a stand alone unit on the firewall. It seems that this was once done before however, the source dried up. This was for a GMC pick up truck.

In your case, you should maybe investigate the inners of the defective unit. You must have some one you know around you that is handy with electronics? Air flow sensors are pretty easy to do, you could have a vane type to spins shaft with a sensor or generator, thermo displacement, ultrasonic or just a simple shutter type attached to a position sensor. etc..

Get your hands on a broken one or something if you can't free up your car to look into this.

Jamie

Broken link. Nobody home. Try again please.

Ouch.

for less than $200?

Start with some rhetorical questions: Are you absolutely sure that it's the MAF that's busted? Have you cleaned the electrical connections? Do you have any test equipment such as a EDB2 scanner, DVM, or scope? Do you have any automotive repair experience?

According to Google search, the Mitsubishi Eclipse uses a Karman vortex sensor. I'm not sure if that's correct. See:

There's a limited number of things that can break in such a simple device. When you post a URL that work, I can suggest where to stick the oscillosope (for the vortex type sensor) to see if there are any pulses coming out, or where to stick the volts guesser (for the hot wire and thermistor type) to see if either is busted.

Incidentally, I fixed the MAF on my neighbors Mitsubishi something. I removed it, cleaned out all the soot, tar, dirt, and filth with a bursh, cleaned the contacts, reset the ECU, and saved them a few hundred dollars. However, that was a hot wire type, which uses very tiny platinum wires. Touch them with a heavy hand, and they'll break.

Note that you really don't want to use any really strong solvents or ones that leave a residue. Use the right cleaner:

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

One more. This one offers diagnostics that can be done with a scope and DVM.

Plenty more on YouTube.

-- Jeff Liebermann snipped-for-privacy@cruzio.com

150 Felker St #D Santa Cruz CA 95060 Skype: JeffLiebermann AE6KS 831-336-2558

Seems to work for me. Here's the target....

here.

can do it for less than $200?=20

No, but 3 mechanics said that would their first guess, including the = dealer.

I found one online for $169, replaced it. Some improvement, but still = runs rich at cold or hot idle and at road speed.

Yes, checked and cleaned those and all the vacuum connections I could = find.

DVM only but don't know what to check or what voltage/current. I was = told this air sensor modulates an output frequency and not voltage or = current. Don't have a frequency meter.

Shade tree mechanic. Pretty fair with pre-computerized systems. =20

Many thanks - I'll check each one! Had to take a break from the car = repair (on the honey do circuit this week) Will be back on it in a few = days. =20

Glad you posted all this. I'm not that advanced, but here's my fix-it = story. This car died about 10 years ago and the mechanic isolated to = the compuer. At that time it was $500+ for a rebuilt. I took the = computer home and open it up. Smell a burnt capacitor -- if you've ever = smell one, you never forget it. Pulled it and replaced it for 10-cents. = Put the computer back in and it's still running 10 years later. Look = up dumb luck in the dictionary and you'll see my picutre. LOL!!!

My favorite of all mascot is the UC Santa Cruz banana slug. What a = sense of humor they have! Beats the tar out of the UC Irvine Anteaters. = LOL!!!

Bob Still slugging way (ugh...)

I always worry about asking people that have a vested interest in selling you a replacement part or installation service.

New, used, or "refrubished"? Seller refurbished usually means they cleaned off the grease and dust.

My guess(tm) would be the oxygen sensor. Bosch sucks. Get Denso or if unavailable, Walker.

The ODB2 scanner is vital as it will display the error codes produced by the ECU. They're can be found for as little at $25. Best of the bunch plug into a laptop, but cost $150. You can watch your mixture change as the engine warms up.

Stone age engines were easy compared to todays computerized nightmares. We're both at the same level. Auto maintenance is a survival requirement in todays world. My Learn By Destroying education tends to be rather expensive but functional. As a last resort, I've degenerated to reading the manuals.

Some of the video cover what looks like your MAF sensor.

Nicely done. I've fixed black boxes this way before. When replacing caps, I try to use a higher voltage rating than stock.

Good things happen ocassionally. My version is that my ability to repair things is cyclic, much like a biorythm. Some days or weeks, I can't fix anything. A bit later, everything I touch, magically fixes itself. I'm sure there's a reason, but I don't want to know.

Well, it almost took a student protest and stike to make the official mascot a banana slug. The adminstration didn't like it, and offered some other animal instead. After a referendum, the students won.

I liven Ben Lomond, where banana slugs are everywhere. Nothing like having one leave a trail of slime across the wall. They also prefer a diet of Motorola service manuals and sticky box labels, both of which I sometimes find chewed to shreds.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com               jeffl@cruzio.com
# http://www.LearnByDestroying.com               AE6KS

John Ferrell W8CCW

Thanks John. Will be the first thing I check this weekend. A buddy = here said he had a similar problem caused by a rat buidling a next in = the tail pipe. Would really be nice to look in there and see a rat = grinning back. =20

Thanks John. Will be the first thing I check this weekend. A buddy = here said he had a similar problem caused by a rat buidling a next in = the tail pipe. Would really be nice to look in there and see a rat = grinning back. =20

Finally after several weekends of checking and minor fixes, so real = progress...

Took the ECU apart and saw corrosion around 2 capacitors. Scrubbed the = board and other board connections looked OK. Replaced the caps with = same only 105 deg instead of 85 deg. All symptoms gone at engine cold = start. Fine when hot, except when in neutral idle speed cycles between =

1300 & 1500 rpm with about 1/2-second cycle time. This is only when up = to temp.

TS guides say that's likely in the intake air flow -- mass air flow = temp, press or flow sensors, idle speed air sensor, motor, etc.

I'm so jazzed that the main problems are solved that I'm going to call = it a day and go have a LARGE burger AND fries!! Maybe even a Bladder = Buster to drink. LOL!!!

Bob