MAF question (I think)

[Jehangir]

Hey all... Been away awhile but glad to read posts from some familiar people. Well... my active 92 Q is having some minor annoying issue. Last week it began to miss a whole lot. So much so that It started stalling out and lost power. I thought it may be fuel related problem, but I don't think so now as the problem is transient without any notable relationships. Inthat I cannot mimic the problem. It just seems to occur at the most inopportune times possible! I'm thinking it may be my MAF or the connector. But I don't know how to differentiate the two. I also cannot seem to disconnect the MAF connector. Although it seems to be pretty snuggly connected. Also jiggling it didn't seem to make much of a difference. I next considered the butterfly near my throdle cable on the passenger side, as one of cables seems kinda loose along with the head it wraps around. I'm not too sure if thats normal or not? And lastly, I know everyone is going to ask about the fuel pump. I haven't checked it with the slave wire. But I don't hear any buzzing back there. Anyway... Thank you for taking the time to read my post and feel free to respond with suggestions. As I look forward to reading emJ.

[96Qowner]

Probably the MAF, yeah. At least, it's the easiest to check and deal with. No change wiggling the connector? Then you should take it out and clean it.

http://www.q45.org/maf.html

It may just be failing. I babied mine for a year, cleaning it in shorter and shorter intervals until I finally broke down and replaced it with a used one. You'll know right away if that was it - should run MUCH better after a cleaning.

Fuel pump and FPCU are doubtful if the pump isn't making any noise.

[goody90q45]

.........I also cannot seem to disconnect the MAF connector. Although it seems to be pretty snuggly connected. Also jiggling it didn't seem to make much of a difference.

I next considered the butterfly near my throttle cable on the passenger side, as one of cables seems kinda loose along with the head it wraps around. I'm not too sure if thats normal or not?

And lastly, I know everyone is going to ask about the fuel pump. I haven't checked it with the slave wire.

The MAF connector has a metal clip that must be removed first. Use a small screwdriver to get under the clip and release one end. Hang on to it as it likes to launch itself when it comes loose. The plug will pull straight out.

It's normal for the throttle cables to have about 1/4" of slack. Don't mess with them.

Your problem could very well be the FPCU and/or the fuel pump. A lot of owners are suddenly having intermittent problems now that we're well into the summer heat. Jumpering the FPCU may or may not answer the question since it is so intermittent.

If you haven't had the pleasure of removing the ECU this may be a good time to do it and look for codes. Easy to do and the instructions are in the Tech Help section at Q45.org. If codes are present it could lead you to the problem and if no codes are there it may point to a fuel delivery issue. Good luck.

[Q45tech]

Unfortunately MAF voltages are tough to diagnose because they vary with rpm, load, air temperature, and barometric air density.

If 1.120 vdc is correct under a certain idle condition EVEN 1.100 or 1.22 MEANS a 10% error in injector flow.............................at the top of range the problem gets expanded.

Always good to have a known working spare to swap to check for symptom changes.

Watch out I had a bad spare that worked fine cold but was flaky hot and another that was bad cold and worked fine when warmed up. Some only failed when moon was full, some when humidity was high or raining, some whenever you hit a pothole [it was not the connector].

[Q45tech]

Remember the ecu only picks up a MAF code when the MAF voltage drops below 1.0 volt sustained so ERRORS are not recorded the ecu just blindly flows what maf says. Rich or lean.

[Jehangir]

Anyone have a MAF and or a MAF connector which works. if so let me know how much with shipping to 70508

[96Qowner]

Check out car-part.com under Air Flow Meter. Any 90-94 will work for you. They're cheap and most NICO posters who've gotten a used one have been satisfied. Today, the cheapest listed is $150, but I'd offer $75 to one of the others. Medford Auto Wreckers has 4 available, for instance. Maybe they'd take $50.

Of course, they're ALL getting old. Used ones will be more of a crap shoot as each year passes.

http://car-part.com/

[Q45tech]

Since the problem with most MAF is crystalized solder connections where the connector or sensor wires meet the circuit board usually caused from temperature cycling and vibrations, repairs to used units are common.