Greetings all,
Has anyone gone to a larger MAF? I have a 97 5.0L and was considering a 75mm. Will everything recalibrate automatically (after disconnecting the battery a while)? I dropped in a K&N and shortly afterwards started getting a PO 171 & 174. I've pulled the power to reset, run several tanks of injector cleaner, and cleaned the MAF with electronic parts cleaner and all was well for a month or two. When the SESL came back on I had the codes checked again and 'lather - rinse - repeat'. Now the light only stays out for a day or so before coming back on. I noticed a guy w/ a clogged filter had 'rich in both banks' codes which would figure if the hi-flow filter gives lean bank codes. I have a set of 1.7 ratio roller rockers to step the valve lift a bit but worry that if Im lean now (presumably because the ECM or other parts can't attenuate the a/f ratio beyond a certain degree) then I'll only be leaner.

Does anyone have any advise or experience with this?

Thanks in advance,
da Celt

 

anybody?? Bueller? Bueller?

 

Bigger MAF = need for bigger injectors.

If you've pretty much got a stock engine internally, that's wasting money.

 

so most any increase in flow will need to be balanced with higher flow injectors. Has anyone put together a matrix of what injectors to use with what type of other mods?

Thanks for the response!

 

The 5.0 comes with a 70mm stock and a 65mm throttle body stock. Unless you supercharge or turbo your engine, you will not see the gains for the money. For what the mas and what one cost, I would put the money into something better.

Larger mas does not always equal larger injectors. A 75mm mas will not add any more air than the stock 19lb injectors will handle. Even an 80 or 85 would not make a difference. To need to go up on injectors, you would need to either use force induction (supercharge or turbo) or go up on mas AND thorttle body size.

There are three integral things that an engine needs to run - air, fuel, spark. These three things have a direct correlation on each other as to how well an engine will run and how much power it make. More fuel = more air = more spark. Of course this works when one of the equation is radically changed. Not just a mas.

Hope this helps.

 

Great advice and I thank you for it. I'm trying to fix a problem and do an upgrade at the same time. From what I read of your message, my stock setup should be able to accomodate a small increase in valve lift. The only thing is that I have a PO 171 and 174 (lean banks) codes already and didn't want to run leaner. I have read that the intake plenum gasket could lead to this problem too...

Thanks again!

By the way Cobra, I see from the pics on your page that you may be a traveling man?

 

If you installed the mas that is programmed for 19lb injectors, and did not install a chip also, you could get those codes. The computer thinks you only have a mas of 70mm - but in actuallity, you have a 75mm that is telling the computer you are getting 75mm's worth of air. The computer thinks it is getting more air than it actually is - creating the lean effect. I'm not saying you don't have another problem that is kicking the codes, because you could (bad mas, injector(s) blocked, O2 sensor,etc). But the 75mm sensor is telling the computer that you are getting that much air, and the computer thinks its only supposed to get what a 70mm reads. Make sense?!?!?!?!?

As far as the lift, the only thing I would check is to make sure the springs match and will work. With 1.7 rockers, you have to bend the valve covers out osme to keep them from hitting. The stock ratio is 1.6. 1.7's will hit the valve cover without bending them or changing to a differnet set. If I were going to 1.7's, I would change cams also to get the best effect. The stock cam in the 5.0 Explorer is worthless in my opinion (thats why I changed mine). I went with a Comp cam and 1.6 FMS rockers. The cam part number is 35-510-8. It calls for 1.6 rockers with part #987 springs. I'm running an Eaton supercharger, so that might be a little strong for what you are looking for. The 35-349-8 might be better for you...

 

Even though I'm in Utah now, I'm out of Stockbridge, GA #691...

 

Madiera Beach, FL #491 here

 

Other than a K&N, I'm fully stock. I didn't get the info on the valve covers before I got the rockers (funny they didn't mention it)... I wonder if there's another set that wont require a hammer? This is starting to sound like more trouble than it's worth. I do appreciate your info, Brother. While I wanted a bit more pep, I will say that a supercharger is a little above what I am looking to do.
Thanks again!

 

Let me get you the numbers on the covers that will fit. Be back in a minute...

 

Look here: Ford Motorsport

These are the part numbers I know of:
M-6000-C302
M-6000-F302
M-6000-E302
M-6000-D302
M-6000-K302R
M-6000-J302

I know these will fit, but you have to run them on the opposite side (neck on driver's side). The neck on the Explorer covers is farther forward than these. The EFI covers have a neck that will be under the throttle body if they are run on the passenger side. There may be other ones besides these, but I know these will fit with 1.7's...

If you are not looking to get too carried away on power and just want some extra pep, I would recommend getting 3 things:

1) Torque Monster headers along with a free flowing exhaust setup using 3" pipe.
2) The K&N FIPK open air filter kit or the Mac Kit
3) A Superchips Tuner

That will get you about 25 - 35 more horses and around the same torque. For the money, that will give you the best results. After that, you have to get into cams, lifters, springs, rockers, heads, port and polishing, etc, etc. - basically more money...

 

Wow! Thanks a ton! I was wondering today if there was an option for this or if I was going to have to get creative with my ball peen hammer...

Thanks again!