For crying out loud, I've replaced this thing 3 times now. The one that was on the car when I bought it was bad, the second one that I got from someone on here was bad, the third one I bought new crapped out after a year (frequency film warped and looked like the surface of a pool, probably because the crappy plastic elbow they put on it to match with the air filter can cracked and broke), and now the film inside #4, which is only 3 years old (and possibly could have been bad for a while), looks like a ramp used for skateboarding tricks, with the top part of the ramp towards the air inlet. I didn't break the elbow installing this second one until I removed it completely to replace with a silicone sleeve for my air intake piping.

What gives? The last time, I almost had to pay $80 to replace this thing, because of the elbow. This time, I KNOW I'm going to have to pay for it, not just because the elbow is GONE, but because I seem to have lost both receipts and you know how the parts stores are... They're supposed to keep transactions with warranties in their computer, but they don't... Same reason I would rather replace the voltage regulator in my alternator for $30 as opposed to buying a new one for $100, even though the alternator has a lifetime warranty on it and is only 4 years old (called about the warranty since I KNOW I don't have the receipt and they basically told me "tough luck" because their records don't show it under warranty).

Another thing jumps to mind: Is it possible to convert the 302 system to the V8 hot-wire MAF, so maybe this won't happen again? If so, how?

 

There's alot of rewiring and some programming to do. Get a tpi bin and copy the maf scalars & tables to the '302 bin. Here's a diagram to help. Then you still need to figure out the burnoff function. Probably better to convert to a '165 & t-bird maf, but I don't think you want to do that just to get around the original maf.

 

I guess the question is whether our series (2.8 V6 across all models) or MAF sensors is the only set that produces a frequency output versus a voltage output... If it is, then one has to wonder, "WTF was GM thinking when they came up with this BS?"

I have found a seller on eBay that is selling NEW OEM GM MAF sensors... I'll try to nab one later this week (if not 2).

Is there ANY way I can keep from having to buy another one until I get the hybrid stuff done?

BTW, I noticed that my parts store MAF isn't built the same way as the GM one... The GM one has the film completely surrounded by the circuit board, whereas this one has the leading edge exposed to the incoming air current, which seems to be the reason it's messed up.

 

Update:

Yep, the MAF is definitely bad again. According to my 87 FSM, the MAF is supposed to put out a signal between 32Hz at idle and 150 Hz at WOT. According to my multimeter (I knew I would find a reason to buy the expensive one other than for ADC readings), its output signal is around 46-50Hz at idle.

I'll tell you one thing, my plugs are no longer tan like they were before with the 84888 fuel injectors. Now that I have the 89569 injectors (also 3.1, same flow rate, supposedly), they're BLACK...!

 

I've heard that a handfull of early tpi cars had a frequency maf instead of hot wire. It was the first design that gm came up with that worked... adequately. So the base models got the shaft and kept the cheap maf instead of jacking up the price with the extra relays & stuff needed for hotwire. Would have been cheaper to go sd, but that's gm for ya. Why don't you convert back to the '730 ecm?

 

Need to get another harness. The one I have has a problem in which the engine runs fine for about 3 weeks before it randomly stalls out in the middle of the road. If I let it sit for about 2 minutes, I can restart and go for about another mile and a half when it's doing this and "limp" home that way. It's a pain. I've gone through the entire ECM side of the harness from ECM connector to sensor or output and found absolutely zip wrong with it. It's not the ECM as the system does the same between 2 ECMs. It's not the ignition module (first thing I suspected) for the same reason AND the fact that the module (and everything else, for that matter) works fine with the 302 system. Well, not fine, but at least I can go from one side of the state to the other without randomly stalling out somewhere.

Might you have any suggestions for that? Also, I seem to be stuck with this code 45, no matter whether I have a MAF or MAP. I have about 3 different sets of injectors, and all of the ones that fail the 3.1 FSM's resistance test have been tossed. These are ALL for the 3.1 engine, BTW... I have the 3.4/3100 ones sorted out of the bunch (easy because they have those light green caps on them).

 

How old's the O2 sensor?

 

Had to buy a new one a couple of months ago when I yanked the 730 harness the last time... My dumb butt forgot to disconnect it from the harness and I yanked the wire out of the sensor (probably because I was so pissed I just wanted to yank that harness and ECM and burn them while performing a dance) . Before that, I don't think it has 30K on it, and it had been throwing code 45 on and off for a while.

I might end up getting a new one with either the newer MAF or the new harness... Running as rich as I am can't be good for it (or the catalytic converter, either, but I'll get that fixed in a hurry).

:edit: BTW, how is it possible that the 91 harness came off of a starter identical to mine and the fusible links that go on the battery post on the starter don't quite fit?

 

Checked for vac/exhaust leaks already? Where did your motor come from anyway? Can't be original.

 

I only have 2 vac hoses running other than the one for the brake booster, one to the EGR valve solenoid, and the other to the FPR and the HVAC, both off of the TB. The small port on the booster tee is plugged with a plugged hose, and so is the factory MAP port on the back of the upper plenum. I don't think I have any exhaust leaks at the moment, but if I do, the AIR pipe in the pass side manifold loosened up again (can't keep the blasted thing tight no matter how much I torque it down). I checked my exhaust manifold bolts a couple weeks ago and they're tight... If I could get to a shop for a reasonable rate, I'd love to smoke test both the vacuum system and the exhaust again.

Don't know about this engine. I DO know it's a 3.1 because I've had the heads off, and no 2.8 RWD EVER came with dished pistons, right? The engine was replaced by the family mechanic before he closed his shop back in 04. If and when I get a chance to find the VIN derivitive, I'll know exactly what year it comes from.

:edit: And no, I don't have a working vacuum gauge at the moment... The one in my MityVac was inaccurate in the first place, and it doesn't work even that well now. Oh, and it's only been the past few days that the MAF has been throwing a code 33. Usually, when it goes, it throws a code 34 (if it throws one at all).

 

Get some brake cleaner and spray around a bit. If you have a scanner you can watch the fuel trim and it should be obvious when you hit a leak. Or put some seafoam through it. Makes leaks stand out well.

 

Still, wouldn't vac leaks cause a low frequency from the MAF and a code 34 or 44? I'm not throwing either (I have about 50Hz from the MAF at idle). I'm getting a code 33 (high flow rate through MAF) and 45 (rich mixture), and the last I knew, vac leaks cause the engine to run lean (code 44), not rich. I don't think I've ever seen a code 44, even when ALL of my factory vac lines were junk (with the 2.8)

:edit: I don't have a scanner, which is why I had to use the frequency test on the MAF. I have the software, but not the cable.

 

It typically won't cause a maf code, unless it's something big like leaving something disconnected. Usually only a problem with the sensor will set a code. My mistake on the code 44. Don't know what I was thinking. The two are related, it's rich because the maf's overreporting.

 

I'll check for vac leaks anyways tomorrow, although I'm pretty sure I don't have any. I need to reset my base timing anyways. I'm going to have to try to get my hands on a cable sometime here in the next month anyways.

:edit: I'm pretty sure the FPR is good as I don't lose even 5 PSI fuel pressure over an hour, nor do I have fuel in the FPR line. Also, I have the CSI in the lower manifold, but it's not hooked up, electrically or to the fuel supply (running a 3.1 fuel rail and I got rid of my 2.8 fuel rail and the spare 3.1 fuel rail back a couple of months ago).