Hi everybody,

I've recently been having problems with my MAF setup. I've been throwing code 33 for the last little while and before my engine threw codes I suspected the MAF was starting to fade away on me anyway.

So here goes, I'd like to purchase a new MAF if possible. I did a lot of research on the Wells su-145 unit but can't seem to find one in the bay area here anywhere. From what I've read, the wells unit has been replaced by a re-built bosch. So if I want to go new, looks like I have to get a Granetelli. But which one?

There are several listings on summit for their adjustable MAF. (Doesn't looke like they make a non-adjustable one for my year) Anyway, I was curious which MAF I need for my setup. Which summit #? It's an '86 TPI MAF system.

I also would like to get an AFPR but also don't know which one to get. I'd like to get a kit that comes with a new diaphram. I like the accell ones, but I still don't know which number to get. Which summit # is the one for me?

Thanks,

-HD

 

I bought the Grantelli and it was a big piece of garbage. Did not fit the air cleaner very well and just threw contast MAF codes. I returned mine to Summit. And the adjustment screw is so small you cannot even turn it. I was very unhappy with it.

I just bought a Bosch style replacement one. Much better quality.

 

Thanks for the honest opinion on the Granetelli. Were you able to find a brand new bosch or is it a re-man? Do you have a part number for it?

Thanks,

-HD

 

The ACDelco Part # 213-163 is a new sensor that is actually the Bosch style but made by GM to correct the problems on the orginal bosch units higer failure rate. These are new but will cost you about $360.

You can get a rebuilt Bosch unit from Cardone at Autozone for $163 but like any rebuilt electronic part their is some risk involved and some cor's are better then others. So look at the part before buying to make sure its not to beat up. They just test the electronics on them and if they pass ship them out.
part # 74-4712

Borg Warner also makes a new replacement that goes for about $230 it can be purchased at Pep boys as a special order. I have not seen this unit so I am not sure what its all about.

Hope this helps.

 

I checked the borg warner online catalogue and found only 1 MAF with the part number 27854. I called pep boys and it's also a re-man.

Anybody else have any suggestions for me since the wells su-145 is no longer available? I really didn't want to drop over $300 on a new MAF sensor.

-HD

 

ok, nevermind my last post, I did find some OEM brand new replacement sensors. Borg warner and neihoff makes them. They're selling for $330, about the same as a granetelli, but if the granetelli just starts problems, I'll stick with an OEM style sensor. Guess I have to pay $330 for a sensor...ick.

-HD

 

Do you know for a fact that your sensor is bad? Have you tapped on it while the car is running? IIRC you start the car and tap on the top of the MAF with a screwdriver or something and if the car stumbles then it is bad but if it doesn't then you have another issue. Hopefully it will save you the $3xx for a new MAF.

 

Concerning the AFPR: the Holley is a user friendly unit. You do not need any tools to adjust the FP with the Holley AFPR, simply turn on the large dial wheel on top.

Previously, I had a Crane AFPR, which works like most other AFPRs. With the Crane, I needed a small wrench and a screw driver to adjust the FP.

IMO.

 

Should I even bother mentioning the MAF relays?

 

Since purchasing my 1989 GTA 5.0 Litre new I have had two MAF sensors installed. The first was an OEM replacement, while the second was a remanufactured Bosch sensor. The Bosch has worked well and I recently removed the screens with no problems yet. Although, there are mixed opinions on screen removal. I am also considering an AFPR and after considerable research I have decided on the Holley unit. Some AFPR have to have their adjusting screws cut to fit into a stock TPI even though they are advertised for these cars. Preform a search of this site by the phrase “AFPR” or “Adjustable Fuel Pressure Regulator” and you will find many posts containing lots of information. The Holley AFPR's instruction sheets can be viewed on the Holley website.

 

He mentioned above having a 33 error code.

The 33 error code is set when three conditions are met;

off the top of my head they are:

1) engine RPM under 2000
2) MAF flow rate above 45gms/sec
3) ????? cant remember this one

The only way that I could get rid of my 33 error code was by programming a new Eprom chip.

Do a search on my user name and above key words. I posted a reply to someone about 6 months ago on this issue.

Many modified MAFed engines (especially 350s) will come up with this error code and there is NOTHING wrong with the MAF or the relays.

 

Check the MAF connector pins carefully. Mine had a pin that would slid up inside the connector when I plugged it into the MAF. Took me a week to figure out that one!

 

I installed a holley AFPR on my set-up. Had to grind the bottom of the plenum a little to clear the AFPR adjustment ****. I haven't heard of many others having to grind, but my intake and runners are Accel/Lingenfelters' and that might have something to do with it.

Also had to replace the diaphram once. Other than those 2 issues, it's been great! Very easy to adj. I can do it blindfolded, with one hand behind my back, on a hot eng!

 

I have put a microtech ajustable mass air flow and it work perfectly,more powerful,more solid.I bought it on ebay.check at http://www.micro-tech-auto.com/

 

Where to buy in Houston, Texas, and how much?

 

I paid 209$ on ebay.com.check on ebay to buy,or check with microtech directly for more information.thanks

 

I can't seem to find any info on an 'adjustable' one on their site and nothing comes up on eBay. I'd go with the wells unit IF you need a new MAF.
I'd still look to those relays first!

 

Hey Howdy,

Like the other guy said, Code 33 is because your ECM is reading more air than stock. I bet your car shimys a little right before the Light comes on and I bet your light goes out if you get the RPM's are over 2000. If I'm right, you should buy a Burn1 chip burner (80bucks) from Craig Moetes and use TunerPro (free software) and change the MAF stuff in the chip. It's very easy. Guys over at DIYprom board can help.

 

More often than not, a '33' is the result of a TPS voltage that is too low. Make sure your throttle body is clean, the minimum air position is set correctly, the PCV is the correct one for your engine, and that the TPS is correctly adjusted. As part of the setting, you should also check the 5VDC reference voltage and connections in the circuit.

If you have altered the MAF, you can also generate erroneous readings at low to moderate flows. If you determine that you need a replacement MAF, you can still get the Wells/Conrad SU-145 through any CarQuest parts store (and other outlets). I just spoke with "Mr. Sensor" today, and he connected me to "Ms. Marketing", who assured me that the unit is still manufactured and available through the CarQuest system and other distributors, like Blain's Supply, etc. I got mine for less than a reman, with a lifetime warranty. I'll never "hot wire" again.

Additionally, if "H.D." also translated to "Handy Dude", you can convert your FPR to an adjustable unit for pennies:

AFPR.pdf

EDIT: I was just going to post "Up your TPS, buddy..." but thought that might not be as well-received.

 

I rotated my Holley from the stock angle postion to horizontal. Plenty of clearance now.

 

Humm, I must have been suffering from a bit of stupiditious.

BTW, nice eng detailing!

 

Thanks for all the excellent info and replies.

The more I read, the more I come to the conclusion that there is likely nothing wrong with my MAF, but my memcal is out of calibration. My engine is modified a bit, nothing extremely wild and I had the chip calibrated to make the engine run. I noticed this problem grew considerably worse after I moved to California from 3500 ft down to 50 ft of elevation. This confirms the idea that I'm too lean when this condition occurs. I've wired in an A/F meter so I can watch my fuel.

You're right, whenever code 33 is set, the meter reads very lean and holds there for a few seconds, then the light comes on, and remains on until I key off, key on. I'm also finding that it's happening during a certain temperature range, while the engine is warming up.

I also need more pump shot, and I'm lean when I have my foot in it about 3/4 throttle...so with both of these conditions I think I'd be wise to invest in a programmer. I'll head over to the "DIY prom" section and find out what equipment I need. Burn1, and a couple chips would be nice, but don't know which one I need. Then I'm set right?

Thanks for sending over the article for modifying the stock regulator to an AFPR. I'll look into doing that in a week or so. I find the engine idles and runs better with the regulator disconnected from a vaccum source. Don't know why, but it likes running at full pressure better.

I've tried playing with the TPS voltage too. I have it set at stock spec (.54) and it seems to run best there. I've tried upping it to .58 and .6

Thanks again for the help, and once I get all the gear together, I'll let you know how the reprogramming goes.

HowdyDuty