Not a mechanic!

I was reading some threads on some of the symptoms my 91 SE is having and wanted to know which MAF I have. 4 pin or 5. I go out to the garage, pull the harness and look at the male pins sticking out of the MAF. 4 pins. I happen to look in the harness and there's 5 female sockets. The rubber back of the harness is cracked wide open and I see 5 wires. My incredibly adept deductive reasoning is telling me the wrong MAF is in this car. Anybody here have a different deduction?

Not a mechanic!

Not a mechanic!

Not a mechanic!

ac max 92

iTrader: (13)

Apparently the maf. for the 91 se is a 5 pin maf. BWD is a pretty good aftermarket brand and the part # you want is 28704M. I believe the 92-94 is a 4 pin. I have a 92 gxe and it's a 4 pin but if im not mistaken the 91 se is a SOHC with the red valve covers too is it not? I believe the se came with the DOHC in 92-94. Anyhow from what i can see you are correct and if your harness has the 5 wires and connector with 5 female sockets then that maf i referenced you the part # for should be the one you want. The 5 pins should be abcde on your maf and f is a blank with no pin. I wouldn't doubt it if that's causing it to run a little rough and the fuel smell from the exhaust im sure is an injector either not seated or missing a pintle cap or something causing it to dump fuel unless for some reason your maf is causing it to compensate if your running the wrong maf which it does obviously appear to be the wrong one. As for your rubber i think we all have that problem. The 94's were a little better with the plastic clips and not the rubber where everytime you take off a connector you worry about losing that metal retaining clip lol. The wires appear to be in good shape and not burnt or broken. I would just get yourself a small container of the brush on electrical tape and patch her up.

Not a mechanic!

Yep....correct!
I am anxious to see how she runs with the right MAF! Thanks AC.

ac max 92

iTrader: (13)

Strange how the 91 se has pretty much the same engine as the gxe but there is some differences I suppose but the part # I gave you should do the trick. I've used BWD products and have had no complaints. It will probably be a little less than oem from the dealership unless you can find one at a scrapyard but the 91 se aren't the easiest to find or maybe there's one on eBay or something. If after your still getting the fuel smell I'd start looking back at the fuel rail and injectors. If it's coming out the tail pipe you don't want to cause damage to the cat if you can avoid it.

Not a mechanic!

Looks like the 91 manual transmission have 4 pin. Auto has 5?!? Not sure but there's a lot of 4 pin for sale out there for a 91 SE. I will get to the parts houses when they open at 7:30 and see what I can find! Pretty excited to see what this does.

ac max 92

iTrader: (13)

If you don't find a descent used one im sure alot of parts stores can get you a BWD one at a descent price. Im interested to see what happens too. Let me know. Im sure that it is a pretty good part of whats causing your symtoms but even if it runs better and you still get that fuel smell i'd go back to checking the injector.

CS_AR

Just noticing this thread references BWD parts. I've had very good luck with BWD parts like CKPS, CSPS, IACV, ECTS, and Oil Pressure Sensors, on my 4th gens.

I usually purchase from Advance Auto online and use the TRT41 discount code for up to $40 off. It looks like the MAF for a 91 will run about $102 + $70 core charge. I order online and pickup the part from a local store in about an hour or get it shipped to my home. The store will give credit for the core charge. Being able to return the part to a store with a lifetime warranty can be handy -- though I've not had to return a BWD part thus far -- knock on wood..

Not a mechanic!

Well, interesting day. Oreiley's, Auto Zone, and Napa...none of them knew what I was talking about. Napa was the worst. He told me there is NO 5 pins made for 1991 Maxima. I told him there was at least one..mine. :-). I called the Feldons Yard that only does Nissan and Infinity and the first thing he asked me was "4 or 5 pin?" I said FINALLY someone who knows what I'm talking about. He had none in stock but could get one by Tuesday. I called Action Auto here (no Advance Auto in the Seattle area) and he ...after I explained the four and five pin details...found one he could get me tomorrow so I ordered it. Have to wait. Unbelievable that all my parts stores in this area tried to sell me a four pin. I now see WHY the wrong one is in if someone had to replace it before. Anyways...stay tuned.

ac max 92

iTrader: (13)

I know what you mean and it's unfortunate. Parts stores hire people at minimum wage that have little to no knowledge on the products they sell. Im sure theres some seasoned retired mechanics out there that may be bored at home that could use some part time hours to help people with their helpful knowledge. Hope you get the right part and it works out. Staying tuned to find out the results

CS_AR

Interestingly the BWD picture from AA's web site shows 5-pins.

Tiniform

Hmmmm! Just checked my 94 gxe and it has a 4 pin but the connector has 5 wires. Could it be that Nissan used one wire harness to fit all? Does anyone one knows which model the 5 pin maf came on?

ac max 92

iTrader: (13)

I believe they did make the harnesses the same why make special production for an extra wire. 89-91 se has the 5 pin.

ac max 92

iTrader: (13)

They make both 4 and 5 pin i believe but thats why i reffered the BWD not to mention they're a pretty good aftermarket part from my experience anyway.

Not a mechanic!

Not a mechanic!

Not a mechanic!

So, here is the FSM for my car. This is out of the EF-EC circutry drawing. Not sure but it looks like 4 wires going I tot he MAF. Of course the other picture is my harness with 5 wires. I am so confused....... Ordered a 5 pin today. We will see.

Not a mechanic!

Actually ordered a 5 pin from Action, picture on the website showed 5 pins...showed up with four. Frustrating......

Have you guys had any luck with Beck Arnley parts? The guys at a parts house said they've been around a long time. It was the only 5 pin I could get ordered without a core charge. Didn't want to pay a core or ship my old one away just in case.........

CS_AR

All I know about AM parts is BWD/SMP/Fel Pro are owned by Federal Mogul that is a Nissan "Just-In-Time" supply partner in Japan and the US. Interestingly, Beck's corporate address is 2375 Midway Lane Smyrna, TN 37167 which is 7 minutes away from Nissan's headquarters in Smyrna TN. Smyrna TN is not a big town.. Those companies must be close for some reason.

If it doesn't work, make sure you can take it back for a refund.

ac max 92

iTrader: (13)

The 92 gxe has the VG30E and has a 4 pin which is probably the more common. Make sure that wiring diagram you're refering to is specifically for the 91 se and not a general wiring diagram for 89-94 VG30E. Like CS_AR said just make sure it's returnable worst case senario.

ac max 92

iTrader: (13)

From what i know Beck Arnley has good aftermarket parts too. Should be fine.

jbbons25

iTrader: (2)

Someone with a copy of an 89-91 FSM should check the troubleshooting procedure for the MAF because on the 94 FSM, it shows that the 5th wire is not used.



I'm using a 4 pin MAF and no problems. Hell, I even experimented with a 4th Gen MAF that has 3 pins and it was working fine. It was running a little more rich, but no hesitation or bogging down apart from the random stalling issue I had.

Not a mechanic!

Thanks lbbons. I never saw that diagram. Same manual I'm looking in. So....hahaha. Looks like it may be a 4 pin and I just have to get a new one of those. AAARRRGGGHH. HAHAHA. Man, what a circus. I've been amazed at how well everything is engineered to fit together on this car. They payed a lot of attention to fit and finish on the engineering. Having an extra wire just didn't seem possible. Oh well, I'll plug the 5 pin in when it gets here and give it a try.

Not a mechanic!

Shipping said the 5 pin arrives next Monday. :-/. Called the parts house that ordered the 5 and got a 4 pin. It was still on the shelf so I went and bought it. Plugged it into the car and drove about 5 miles. Runs better than it ever has. No sputtering or gas smell. Cautiously optimistic. Going to take her to the freeway and see what happens. :-)

Not a mechanic!

Nope. Spitting and sputtering again. Guess it's time to check the injectors AC Max 92. I have a suspicion you're probably right.

Not a mechanic!

Well, AC max was right. Pulled the intake down to the fuel rail and #2 was dripping even before I turned the key. Then it was gushing. It was the small lower o-ring that got pinched somehow. Had some spares and greased it up and no more leak. Feeling so weak I am having a hard time getting out there today but I will.....just a few more things to reattach and I'm DONE. I think,,,,

Not a mechanic!

So, I put the reman MAF on and it seemed to be working great. Got the fuel inj leak fixed and drove about 8 miles and came home. Seemed to be running good. Pulled in and it died. Trouble code 12. Mass air sensor. :-/. I do have the supposed 5 pin showing up here in the next couple days so I'll swap it out and see what happens.

ac max 92

iTrader: (13)

I think the biggest thing is that you got that fuel leak fixed Now you just gotta get that maf swapped and hopefully she'll run great and everythings happy. Sorry to hear your feeling weak. Don't work yourself too hard. The holidays are time to relax. Even if the maf is supposed to be a 4 pin and that 5th wire is an extra i don't see that the 5 pin should make a difference or cause any issue but from what i've seen the 91 se has a 5 pin maf but that was only one site and maybe a little more research could be done to confirm that but i think you should be fine. Wishing you and yours a very merry christmas and relax a little good heath is important!

Not a mechanic!

Well, my new 5 pin showed up .......with 4 pins. Hahahaha . I'll try it out today. 4:30 AM now. I will have it in by 6 and go for a little drive.

Not a mechanic!

Starting to really live up to my handle here. I plugged the second new 4 pin in and the trouble lights are gone again. Unfortunately I could still hear a miss in the exhaust. I pulled the plug wire to number two....AGAIN.....and no change in the idle. Plugged the Noid light in and, unlike before the new computer, I have pulse power to the injector. Pulled the plug and it was covered in black soot from when it was leaked into I guess. I cleaned the plug off and switched it with number four for good measure. Great spark...check. Pulse power, check, compression, check. Injector fail? I pulled the freaking intake for what seems like the 5 th time. Pulled the injector and plugged another one in its place from the left overs of the 2 engines. The guy who rebuilt the injectors put a big X on the bad ones so I knew it was a working injector...just not rebuilt. Put it all back together again. Fired it up and the loudest whistle I've heard from an engine compartment ensued. I managed to go pull the number two plug and verify the idle changed! It was really hard to hear where the whistling was coming from. Ear piercing!! I took the extension tube for my shop vac and put it to my ear and moved the other end around the compartment until the screeching was unbearable in my ear attached to the tube. . I had all my hoses plugged in so I ran my fingers around the loud zone until the whistle changed......between the upper intake manifold and the lower parts. Must have pinched the gasket this time.
Ok....closed the garage and went in......tomorrow is another day! I may bring the failed injector back to the guy who rebuilt it to confirm it went bad. Rebuilt it or another one and plug it in since I have to take it apart.......again. Too funny.

ac max 92

iTrader: (13)

It's frustrating but you'll get it running right. Im sure your persistance will pay off not to worry. It's funny because before i got to the end of reading your last post as soon as you mentioned the whistling i thought to myself it's gotta be that intake manifold gasket seeing the poor guy has taken it apart and put it back together so many times. Take the multi meter to the injector you have in question or all being your taking the intake down again and just confirm they all read between 12 and 14 ohm. Sometimes when replacing the injectors it's best to pull the fuel rail out which is 4 screws just to make sure when your installing the injectors they're all seated properly.

CMax03

iTrader: (3)

Look just replace all your injectors....I would suggest investing in brand new injectors but if that's too expensive, partsgeek.com has some GB injectors that are inexpensive as hell and worked great on a few VG's I repaired for students that were on a budget...and they seemed to last and never had anymore issues regarding leaking, open solenoid injectors etc...

Not a mechanic!

Yah...and put a new gasket on EVERY time. the first two times Oreilys sold me the felpro pack that was 62 dollars. Last time they finally found the 8.00 set!
Do you RTV the cheap ones? The nicer ones have a rubber outline.

Not a mechanic!

Thanks CMax! I did rebuild them but a factory rebuild may have been better. Mike Wright has had his mechanics shop specializing in fuel systems open for over 30 years. I do like and trust the guys work.

Not a mechanic!

Success!!!!! Runs like a top! Idle is awesome. Exhaust sounds smooth and it drives like a dream with 4 new struts! Pulled back in the yard and steam was rolling out of the hood. Blown WP hose. Hahahahahahaha. Done for today and happy. 3 quarters of the Seahawks to watch! GO HAWKS!!!!

ac max 92

iTrader: (13)

Awsome. Glad to hear you finally got it running smooth. Im sure with the injectors properly in place and new intake gaskets she should run smooth for some time now. When changing that coolant hose there is an 8mm bleeder screw at the back of the upper intake manifold near the pcv valve. Remove that bleeder screw when you top it up and get it up to op. temp. make sure you get all the air bubbles out before putting the bleeder screw back in so you dont run into any over heating problems or air locks in the cooling system. Im glad to hear you got the mis and it's now running smooth like it should. I figured that your persistance would finally pay off

Not a mechanic!

Wow! Didn't know what that little screw was for! THANKS AC for the coaching and help. It made a difference! So, I need to drain the coolant and replace the hose and THEN run the engine while refilling with that screw still removed? Put the screw in when steady coolant starts flowing from the hole? Interesting.

ac max 92

iTrader: (13)

Yes sir. You got the just of it. I'd put some coolant in before starting it up though it will take a little while idling for the car to warm up to temerature. Fill the coolant through the rad slowly and watch until the bubbles are gone out of the bleeder then replace the screw. Once the rad is topped up and there is no bubbling and just a nice swirl your good. I'd leave it idle for a bit once it's warmed up to let the thermostat open up allowing the coolant level to drop in the rad and then slowly top it up then top up the resevoir a little but well below the max mark and you should be good to go . From there just keep an eye on it for a few days and if you have no issues you should be fine.