Delphi MAF issue
#1
Delphi MAF issue
Figured I'd post the question before the story. Is anyone else having problems with Delphi MAF's? Any way to test them with a multimeter?
I recently installed a Delphi 10320 maf sensor to replace a stock bosch maf that gave constant code 36 burnoff issues. Now I have a rich condition (black smoke, eyes watering) and surging and dying at idle. The firebird had a rich issue before, but not nearly this bad. A little digging in this forum has shown other people having problems with the Dephi circuit board mafs. I am about to buy a reman Cardone 744712. Seems to be just like the stock Bosch with the wire.
The list of sensors I've already replaced are:
1:Coolant temp sensor to ecm
2. Tps
3. IAC (It was seized, probably should have changed this before the MAF)
4. ECM (crack in motherboard.)
Was not able to set IAC and TPS as per GM service manual instructions due to not being able to set idle low enough without dying.
I recently installed a Delphi 10320 maf sensor to replace a stock bosch maf that gave constant code 36 burnoff issues. Now I have a rich condition (black smoke, eyes watering) and surging and dying at idle. The firebird had a rich issue before, but not nearly this bad. A little digging in this forum has shown other people having problems with the Dephi circuit board mafs. I am about to buy a reman Cardone 744712. Seems to be just like the stock Bosch with the wire.
The list of sensors I've already replaced are:
1:Coolant temp sensor to ecm
2. Tps
3. IAC (It was seized, probably should have changed this before the MAF)
4. ECM (crack in motherboard.)
Was not able to set IAC and TPS as per GM service manual instructions due to not being able to set idle low enough without dying.
Last edited by 89Formula2; 06-05-2023 at 06:44 AM.
#2
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Car: 1989-92 FORMULA350 305 92 Hawkclone
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Re: Delphi MAF issue
Have you checked the fuel psi regulator vacuum line for raw fuel ?
#4
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Re: Delphi MAF issue
Well check out the vac line and let us know what you find. Good luck
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Car: '91 Firebird Formula
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Transmission: Tremec T56
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Re: Delphi MAF issue
Delphi MAF issues
MAF issues
How to diagnose a MAF
Code 36
Code 34
https://www.thirdgen.org/forums/afte...or-review.html
https://www.thirdgen.org/forums/tech...t-ok-then.html
https://www.thirdgen.org/forums/tech...f-reading.html
MAF issues
How to diagnose a MAF
Code 36
Code 34
https://www.thirdgen.org/forums/afte...or-review.html
https://www.thirdgen.org/forums/tech...t-ok-then.html
https://www.thirdgen.org/forums/tech...f-reading.html
Last edited by SbFormula; 06-05-2023 at 09:43 AM.
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Vader (06-09-2023)
#6
Re: Delphi MAF issue
Thanks for the info guys. I'll check the vacuum line and maf readings after work. What are all of you using for a scanner? I have two obd2 scanners but they don't work for obd1.
#7
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Car: '91 Firebird Formula
Engine: SP383 Deluxe FIRST® TPI Intake
Transmission: Tremec T56
Axle/Gears: Moser 9" Eaton Truetrac Motive 3.89
Re: Delphi MAF issue
I recently installed a Delphi 10320 maf sensor to replace a stock bosch maf that gave constant code 36 burnoff issues. Now I have a rich condition (black smoke, eyes watering) and surging and dying at idle. The firebird had a rich issue before, but not nearly this bad.
For being too rich BEFORE: do you still have the original injectors?
Thanks
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#10
Re: Delphi MAF issue
Looks like the new Delphi MAF aggravated the problem. Not surprising. I would put the old MAF back on and ignore code 36 for now. The Delphi MAF, most likely, has the "voltage reading" issue described in the above posted threads.
For being too rich BEFORE: do you still have the original injectors?
Thanks
For being too rich BEFORE: do you still have the original injectors?
Thanks
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SbFormula (06-05-2023)
#11
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Car: '91 Firebird Formula
Engine: SP383 Deluxe FIRST® TPI Intake
Transmission: Tremec T56
Axle/Gears: Moser 9" Eaton Truetrac Motive 3.89
Re: Delphi MAF issue
Unfortunatly I do not have the original maf anymore, I cored it out. The PO installed new injectors right before I got the car. I can't see any part numbers on them, so I am very suspicious of them as well. I have Bosch 19lb gen 2 injectors from Southbay, and a Holley adjustable regulator waiting to be installed.
Good luck
#12
Re: Delphi MAF issue
I solved the tune problem with ordering a stock tune on a replacement memcal from Tuned Performance. There was an old hypertech stage 1 chip on a moates piggyback for a 350. My firebird is a 305. The chip and the piggyback were all soldered together, that's why I just ended up getting a good used memcal.
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SbFormula (06-05-2023)
#14
Re: Delphi MAF issue
Update: Replaced Delphi MAF sensor with and reman Cardone 744712. I'm back to where I began. Slight rich condition, but not spewing out black smoke from the tailpipe. So the Delphi MAF was definitely defective. Tested fuel pressures. It was 36 at idle and 42 with just key on. Seems good if I'm not mistaken. I'm going to go ahead and swap in the Bosch injectors in a week or two.
Last edited by 89Formula2; 06-08-2023 at 07:12 PM.
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SbFormula (07-13-2023)
#15
Re: Delphi MAF issue
Got antsy, replaced the injectors. Cleaned the intake plenum and runners at work. Installing the Holley fuel pressure regulator, egr valve, intake temp sensor, and reassembling everything by Saturday.
#16
Re: Delphi MAF issue
Problem solved. The injectors worked like a charm. I guess the previous owner installed the wrong injectors. No fumes from the exhaust, much better throttle response, and getting about 20-22 mpg cruising on the highway. Thank you everyone for the help.
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TTOP350 (07-12-2023)
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