How To: 4.0L OHV MAF upgrade....

[2000XPLORERSPORT]

The stock maf doesn't have a bar. Just a narrow hole.

Maybe the later gens are different.

actually my maf is plastic.but there is a piller inside from top to bottom.but i don't think its worth the chance to mess it up for a little improvement.if any.im not saying he didn't get any improvement from switching to the 5.0 maf,but i don't think its worth it for mine.

 

[97Exploader]

Stock 5.0 foxbody mustangs have 19lb/h injectors yes?

YES they do.

 

[Spdrcer34]

Your best bet is to pick up a 5.0L Explorer MAF, and modify it....

Just make sure you use your 4.0L electronics on there.

Ryan

 

[seth247]

I'm not saying anyone is wrong.

But I would NOT modify any kind of maf without proper ECM tuning.

If vehicle the maf came out of has the same injectors as yours and the same style sensor, then i think it is safe.

I would even use the sensor that came with that housing. The electronics are tuned to the maf not the vehicle. Putting the explorer electronics in will make not make it ok to use any maf. It HAS to be one with the same Injectors.

The whole reason that bar is in the airpath is to force MORE air into the sensor, so that the proper ratio of air to the sensor is maintained. Ripping it out will cause the ratio to change towards more air in the main housing than is goin to the sensor.

Which will cause the sensor to read less air than is acually going through the housing. Causing a lean condition.

Luckily ford is pretty good at the whole design thing so unlike some brands there computer can make up for the false reading with o2 sensor data. Which is probly why you felt the increase in performance.

But there is only so far the computer can adapt. Even fords. And I wouldn't push it.

I use to have the vortec maf installed on the truck. Was just a tube with no bar or nothin. I didn't like the way it made my A/F gauge read so I yanked it and it's sitting in my garage.

Now I'm no expert. I've embraced the fact that it's entirley possible I'm wrong about everything.

But James is an expert and if be says it's a bad idea I ain't gonna do it.

But you must all make your own decisions.

I still think it's ok to use the mustang MAF as long as it stays intact.

 

[Jakee]

Back in the old days they use to "Calibrate" MAF sensors mechanically sort of like I see here. The bar that was removed was part of this.

Guys, it’s hard to mess up a N/A vehicle by doing something this small. The wire will cool faster probably but the fact remains that the sensor will pick this up and it’s not enough to cause any ill effects. I would think some sort of code will trigger if not and the thread starter didn’t report this. I’ve seen this mod done before on other forums and no one has stepped up to the plate and said it did any damage. I believe its safe but don’t expect too much of a gain from it.

Of course a tuner is going to say you need another tune…

 

[tyler_h]

i did the same mine came of a v8 thunderbird

 

[Spdrcer34]

There was NO CEL at all when I did this on my old 4.0L

As a matter of fact, I never had a CEL after any of the mods that I did.

Ryan

 

[jah81592]

Back in the old days they use to "Calibrate" MAF sensors mechanically sort of like I see here. The bar that was removed was part of this.

Guys, it’s hard to mess up a N/A vehicle by doing something this small. The wire will cool faster probably but the fact remains that the sensor will pick this up and it’s not enough to cause any ill effects. I would think some sort of code will trigger if not and the thread starter didn’t report this. I’ve seen this mod done before on other forums and no one has stepped up to the plate and said it did any damage. I believe its safe but don’t expect too much of a gain from it.

Of course a tuner is going to say you need another tune…

Log it and you will see I am right. I am not trying to sell a tune because I have to be with the vehicle to tune an EEC-iv anyway. Ill effects, hmmm. Lets see I bet the short terms are off so bad it isn't even funny. As long as the meter isn't pegged or consistantly stuck it won't trigger a cel, but I guarantee that there would be enough of a change in the A/F's you would be surprised. Also the EEC-iv doesn't monitor the stft's like the EEC-v(obd-ii) so if the vehicle is excessively rich or lean it WON'T report with a CEL. The EEC-v will monitor trims closer with a narrow window. You can mess up an engine if it is too lean and consistantly pulled at wot. So please don't misinform.

Like I said I tune all sorts of radical EEC-iv combo's. Without logging to prove anything this is he said, she said. And like you said in many other forums, there is the problem, unfortunately some people are only "keyboard racers". Without facts how can you approve.

BTW- Your little remark of a tuner is going to say you need another tune is a bit out of line and I knew what direction you were pointing at. I believe any moderator will agree. This has basically been a dead thread from May till Jan. Now that it has been revived please don't mess it up for the thread starter with the fate of it being closed!-j

 

[Jakee]

James - I'm stating my opinion only. I'm not trying to say you do anything wrong, because god knows you don't.

No, the air-fuel is not off that far by doing this. I know that for a fact.

 

[rustbucketMI]

Just tried this today, while being in a rush because it was -5 at the junkyard where i was getting a new MAF i pulled one off a T-Bird. Doesn't have the flange to bolt up to the airbox. If i had been paying any sort of attention i would have noticed this. As a result i am going with a complete cold air kit.

So if anyone wants to attempt this make sure you get the correct MAF. as low as $10 on E-bay right now

 

[gsx220]

i use to run a modified MAF on my gsx but i also ran an apexi fuel controller and datalogger so it wasnt an issue but by all means you can make you car run lean or rich messing with it i have to agree with james on this one without any datalogging i wouldnt touch the maf

 

[Jakee]

Well, I guess I'm not paying attention very well on this thread. I thought this was a stock 4.0 MAF sensor housing being modified. I just re-read and see you are using another MAF that's way bigger and also modifying it. This is dangerous – be very careful trying things like this.

If this were like I thought and the stock MAF was being modified a little bit then I wouldn’t worry at all. Yes, the air-fuel will be a little different and technically this isn’t “right” but I knew for sure it wouldn’t blow the engine up.

So I apologize on misleading anyone on this because James is 100% correct. James - Yes, unfortunately I am a keyboard racer.

 

[XxxMonoxideChild]

i have a 5.0 maf housing. i also swapepd my 4.0 electronic's over to the 5.0 housing. i didnt gut mine at all though. left it as one entire piece.

i did it about a year ago, havent had any issue's. didnt notice any real power gain. but i jumped 2-3 mpg when i did this, and the cone filter install at the same time.

intake is alot louder also. wish i got a more noticeable power gain. but the gas mileage increase alone makes me happy.

 

[nak4af]

Did you disconnect the battery so it could re-map the sensors? If so, then a chip will grant you a power increase you should feel.

 

[Anime]

You can tune a gen1 Explorer with a SCT chip. I have datalogging,etc. Unfortunately I have to be with the vehicle. It can be done. I also tune many Fox bodied Mustangs. If you are close to me I can tune you. If you would like to schedule time, just let me know. Chipping a Gen1 isn't impossible.

What is the equipment setup for chipping, datalogging, and tuning?

I've been looking for a way to do this.

 

[chris12491]

i have an 88 gt 5.0L, yes stock they come with 19lb/h injectors, im not sure if it is the same as the X

 

[2000StreetRod]

fuel economy or performance?

Since this thread has been revived after 18 months I decided to express my opinions regarding MAF sensor swaps.

Utilizing a larger diameter than stock MAF sensor without PCM compensation will lean the A/F ratio. This is because the speed of a specific volume of air will decrease as the diameter of the tube increases. The MAF sensor outputs a lower voltage corresponding to the lower speed and the PCM adjusts the fuel injector pulse width accordingly.

Some forum members have performed MAF sensor "upgrades" and claim to have experienced performance improvement with no harmful effects. If the O2 sensors are functional and the fuel trims are not near their limits when the MAF sensor is replaced, the PCM will detect the lean condition (via the O2 sensors) and increase the fuel injection pulse width by adjusting the fuel trims. As long as the trims can be adjusted within their limits no CEL will be set and the engine will exhibit normal A/F ratios when the PCM is in closed loop. There may be a slight increase in fuel economy due to reduced air flow restriction.

However, most members perform the MAF sensor "upgrade" striving for increased acceleration rather than increased fuel economy. The PCM determines engine load using the MAF sensor and TPS outputs. When engine load is high [as during wide open throttle (WOT)] the PCM operates in open loop reverting to programmed data tables to establish A/F ratios. The stock tables assume a stock MAF sensor and the engine will run lean with an "upgraded" MAF sensor unless the tables have been modified with a custom tune. The lean fuel mixture will decrease engine power and increase combustion temperatures while again improving fuel economy. Combustion chamber detonation is possible - especially with the V8 and OHV V6 that have no knock sensor.

I have first hand experience with the above issues having upgraded my stock 55mm MAF sensor with a 90mm lightning sensor. I experimented with an amplifier that could adjust the MAF sensor outputs in real time and monitored the fuel mixture with a wideband A/F ratio meter. I also monitored fuel trims with a scanner and recorded A/F ratios during multiple WOT runs from 0 to 90 mph and hours of normal driving. I strongly advise a custom tune in conjunction with any MAF sensor "upgrade".

 

[Kona]

Can I get some advice from this dead thread ? I just bought a second hand "performance built" 4.0 OHV (will get more info soon ) with a hotter cam ,headers ,BBK throtle body and a bunch of other work done ( was supposedly $6000 Canadian spent on it ) at a quality engine builder. It has the all the stock sensors (MAF) , what do I need to do to get close to it's potential from it ?

 

[Dono]

Get it breathing. larger maf, larger intake, open up the exhaust. What size is the BBK?
Im sure the cam is the Comp Cams 422. Compression ratio? More info required.

You will need tuning done. Either Dyno, or remote tuning by sending logs off via email.
Remote tuning requires a wideband o2 sensor and sct tuner.

Im looking froward to hearing more on this.

 

[2000StreetRod]

Obd-i

I assume you purchased the engine for your 1991 Ranger which is OBD-I. Unfortunately, remote tuning is not possible with OBD-I like it is with OBD-II. To realize the full potential of the modified engine you will need a custom tune. Does your stock OHV V6 have the 55 mm MAF sensor which also was used on the SOHC V6? I suspect the maximum air flow of the modified OHV will be comparable to the maximum air flow of the stock SOHC V6. Therefore, your stock MAF sensor should be adequate. I suggest that you obtain an estimate for a custom tune by your nearest dyno shop. The cost estimate should include temporary installation of a wideband O2 sensor to monitor air/fuel ratios during the tune. When you have funds put aside for the custom tune then install the modified engine and drive to the dyno shop.