MAP Sensor *Speed Density* Foxbody

[@jpp9846]

*Update, that code 22 is gone. That MAP Sensor was defective. So...just because it's a new part, doesn't mean it's functioning properly 👍

[@jesusisalive3227]

Exactly, my boy had the voltage regulator go bad on him in his 74 f100. He had two brand new regulators in a row that were bad. I ended up grabbing one off my 72 f100 project truck, "which was an old mechanical regulator," to get it going. The parts coming from the stores lately have been terrible.

[@awh5773]

ok guys . i found out that my cousin actually has a ford dealership service manual and he sent me directions on how to check these damn sensors and it does work . so here goes. On ford applications, a multimeter that can read frequency ( Hz) is normaly required to check the sensor output ( middle wire ) , but you can use an ordinary tachometer because the tachometer can display a frequency signal. (1) set the tachometer to either 4 or 6 cylinder engines. (2) connect the tach (positive) lead to the ( middle) wire / terminal on the MAP sensor , and the ( negative) tach lead to ground (3)connect 2 jumper wires same as before. attaching each jumper wire from the sensor to the respective wire in the connector (4) if you want to measure engine vacuum so you can correlate it to a specific frequency reading , connect a vacuum guage to manifold vacuum or ( TEE ) into the MAP sensor vacuum hose (5) turn the ignition ON (koeo) and note the initial reading. the reading on the tachometer should be about 454 to 464 rpm`s on the tachometer at sea level , which corresponds to a frequency output of 152 to 155 (Hz) on the multimeter (6) start engine ( koer) and check readings again. if the MAP sensor is functioning properly , the readings should DROP to about 290 to 330 on the tachometer. which corresponds to a frequency output of about 93 to 98 (Hz) on the multimeter . NO change would indicate a defective MAP sensor or a leaky or plugged vacuum hose hope this can help some of you guys , this is for 1986-1994 Ford , Lincolin and mercury cars and trucks with gas engines. i did it last nite and it works. i made 3 wires black ( ground) , green ( middle ) , and red constant positive feed from computer 4.0 to 6.0 volts . and ran them from the sensor to the connector. i also stripped some plastic coating off of the wires i made so i could hook up my tachometer and multimeter. the multimeter is one i got at harbor freight for around $20 ( make sure you get a multimeter with (Hz) setting on it ) and the tachometer is one you can get off the shelf at any parts store and get some gator clips to put on the wires on the tachometer i really do hope this helps you guys

[@williamjones8283]

Thank you, you are the only person that did an in depth video about the “Vacuum Tree”

[@lilibethdoherty295]

That is a Clean Mustang you should be very Proud, mine has 260 K Miles and now runs Rough I will try a new Map Sensor Thanks.

[@jesusisalive3227]

If you are having issues with the map sensor you can unplug the electrical connector and the car will go into a limp mode so you can get home. This will also help diagnose a dead sensor if your car won't start.

[@VictorMarquez-vi9fg]

Can you explain this explanation!!

[@jesusisalive3227]

@@VictorMarquez-vi9fg What part?

[@VictorMarquez-vi9fg]

If you disconnect the power supply plug, and the car goes into limp mode, it means the sensor is no good?

[@stephanmendoza86]

You are amazing I loved the info you should do more different FOXBODY videos especially that they are so hot right now I'm sure more people could use help in different areas in a fox including me lol🙏😊

[@jpp9846]

Thanks, appreciate the words. I haven't been doing too much to the car lately, she's running great and life has me busy with other things. I do plan on doing a few things more towards winter, possibly a Cylinder Head install, a TermX ECU swap and some other body part changes (Cobra bumper). I just have a lot going on right now. Thanks for watching 👍

[@fwh79FOXR6]

Excellent video. It seems like everyone is getting burned by bad "new" parts. I'm sure plenty of speed density cars have a MAP sensor that is not being feed vacuum correctly. Your car is looking great. The engine bay looks really sharp with the Cobra intake!

[@jpp9846]

Thank you! I agree some of these 'new" parts are junk, right out of the box. Some old customer of mine, who has a mechanical background, told me some part boxes say "test" on them. Those are ones that are remanufactured? I didn't see that on the box, but will look closer next time. I'm going to drive it some more this weekend, if I don't have it up, changing out the fuel pump. Hopefully, this issue is behind me now!!

[@fwh79FOXR6]

@@jpp9846 I think you got it figured out. The new fuel pump will tie it all together. Then you can tweek the fuel pressure and be good to go. Your new complaint will be lack of traction and excessive tire wear.

[@jpp9846]

@@fwh79FOXR6 hahaha....I can definitely see traction being an issue now and in the future. Thing will not hook in second gear if you're on it, just spins. It did not do that with the old intake, I think this Cobra Intake upped the performance. Thanks for.your help!! 👍

[@fwh79FOXR6]

@@jpp9846 You're welcome. You did a great job with the install and it looks damn good! Now you have first hand experience with long vs short intake runner lengths.

[@jpp9846]

@@fwh79FOXR6 it still seems strange to me that this Cobra Intake makes the car breathe better than that Comp Bread Box. Only because the the air had less distance to travel into the cylinders, with that shorter run in that plastic box...does that make sense? I don't know, maybe the velocity has something to do with it too. It definitely runs different though. Seems to have a lot more power in the higher end now. Maybe it was equal throughout with the other intake?

[@MN-vw2lo]

I've been searching for a fix for my idle issues. I have an 86 with no MAF, and GT40 intake installed (bought that way). My car idles at 2-3k on start up, then drops down to about 1k after a few seconds. If the idle drops below 1k then it starts fluctuating and will sometimes shut off. I've replaced the IAC, checked for vacuum leaks, adjusted the TPS, and checked the timing, and nothing seams to help. I'm 90% certain that my B/P port on the vacuum tree is capped off. I can't wait to get home to check it. I really hope this fixes my problem because it has been a nightmare.

[@jpp9846]

Check your vacuum lines and be sure they routed correctly... Especially the MAP

[@MN-vw2lo]

@@jpp9846I checked and the MAP vacuum line was routes to a 3 way fitting which connected to I think the lower intake manifold and a blend door right below the EGR. I removed the line and plugged it into the vacuum tree but it was a little big, so I zip tied it, but I think it’s still too big because it was still running rough. I need to get some vacuum line. I also capped off the 3 way fitting.

[@MN-vw2lo]

@@jpp9846 I’m also going to do another base idle reset and check my timing

[@jpp9846]

It's been a while since I did this video. But I can link a vacuum line picture that tells you how to route those vacuum lines

[@jpp9846]

www.thelincolnmarkviiclub.org/phpBB3/viewtopic.php?f=15&t=6149 This is for a Lincoln Mark 7 upper manifold, but the vacuum lines are the same, since the Lincoln is also a Foxbody. The 3 port vacuum tree under the upper manifold is shaped different on the mustang, but has 3 ports like the Mark 7. Also, I was going to suggest the base Idle reset. The Brew2L channel out here has a very nice step by step video. I suggest watching it. I have all the service manuals for mine, but his video is the correct procedure too

[@jerellis1983]

Stang looks sharp! Is there a walk around video? Sucks we can’t trust new parts. Lol

[@jpp9846]

Thanks! Yes there is a walk around, it's my very first video posted out here. kzbin.info/www/bejne/eqm3q4ShaMqdZqc I agree, got scammed on a "new" part 🙄

[@nortexgemgaming8589]

what part/line does it go on the intake the pcv or the 3 hosed thing not sure my fox is running like crap

[@jpp9846]

What year is your Fox? I don't think that matters, so long it's routed to the intake. I believe mine is attached to the center valves on the backside of the manifold. Several things contribute to it running like shit. Have you pulled codes? I always start there.

[@rolandtamaccio3285]

Naw , I drilled right into the top of the manifold , and get all vacuum there , and it's finally running right .

[@mw7788]

Brother I have an 87 that I bought from some geekers several years ago. I'm all in now because I'm pretty sure I'm gonna die or go broke before it's back to goid.

[@chadmcdavid6072]

We're does the hose go that comes out of the map sencer

[@jpp9846]

To the intake manifold with speed density, there is no line from the map (bap) with MAF

[@timzzz9963]

I have code 22 right now. Car runs crappy stalls at lights and up and down idle. I think its time to get one of those.

[@jpp9846]

What year is the car?

[@timzzz9963]

1986 5 liter gt

[@jpp9846]

@@timzzz9963 then it's a speed density if you don't have a MAF conversion. I'd make sure there is a vacuum line from the manifold to the tree on the firewall. Or, it may be fine, but the line has a hole in it causing a vacuum leak. Code 22.definitley points to a MAP problem. Just beware, if you buy a "new" MAP sensor, you "might" get a bad one like I did. So re-check your codes after 20-30 miles to see if 22 is still showing👍 Good Luck!!

[@timzzz9963]

Thanks for the help im going to look at the existing map this weekend and the vacuum lines

[@jpp9846]

@@timzzz9963 yes, do that first...might just be a vacuum line. Them things get weathered and brittle. Hope you find your bug, I think pulling codes is the very first step to solving issues with these Fox's. Let me know if it works, people are always looking for help with these cars. If I can help one person, it's worth while.

[@murphytoadster9864]

Sounds Identical to my broncos problem. I was about to go buy a smoke machine

[@werdCanada]

can you use a e7fz-9f479-a sensor on a speed density mustang?

[@jpp9846]

Map Sensor?? Is it from a MAF 89-93 Mustang??

[@werdCanada]

map sensor, 87 speed density setup*

[@jpp9846]

@@werdCanada where did that map sensor come from? That you want to put on the Mustang?

[@werdCanada]

he said its off a 87-93 mustang but being a fool i bought without running the numbers, seems to come up as an f150 and truck application, bought another 1 e7ef-12a644-a1a, this 1 should be the correct one no?

[@jpp9846]

@@werdCanada yes, it 'might" work, but if you know it's not off of a Mustang, you might run into other BS. I was asking what it came off of,for this very reason. My understanding is that the MAP sensors were the same 87-93, but with a non speed density set up, you do not run a vacuum line to the intake, it just stays unplugged and vents into the engine bay. VERY important to run a vacuum line to the intake manifold on Speed Density setups. I hope this helps. But I agree, I'd use a 87-93 MAP sensor, especially if yours is Speed Density. Speed Density relies heavily on this sensor to operate correctly

[@frankbabiarz4262]

Check out foxcast and Brew2L have great information on there KZbin channels. They don’t mess with speed density much or at all but great information

[@jpp9846]

Both good Foxbody channels. You're right, neither of them seem to know anything about Speed Density, this is where my channel "might" help folks with Speed Density. Although I will be converting mine to MAF soon, along with some other mods.

[@alvaropimentel779]

How do you do a test smoke 🧐

[@jpp9846]

kzbin.info/www/bejne/a3vbooFseKqpb7M

[@jpp9846]

kzbin.info/www/bejne/iJPbqGqFnruHbJY

[@mazinalmaimani7291]

Thanks man its so helpful . I have a question do you know TPS Wiring diagram because i am having a problem that soon as i touch the TPS wire slightly shifts the RPM so high and stays there for few seconds and comes back and when i hit the Throttle theres a hesitation and lag. If anyone knows the issue a help would appreciated . Regards 🌸

[@mazinalmaimani7291]

Its a foxbody 1988 5.0

[@jpp9846]

Sounds like maybe the TPS is not sitting correctly in the Throttle body seating? I'd unscrew it and make sure it's sitting properly into the seating on top of the Throttle body. I would also turn down the idle screw under the Throttle body. But beware, Everytime you adjust that idle screw (up or down), you also mess with that TPS setting. Hope that helps.

[@mazinalmaimani7291]

@@jpp9846 thanks alot Champ i appreciate your advice i will try that 🌸.

[@jpp9846]

@@mazinalmaimani7291 good luck!

[@jpp9846]

@@mazinalmaimani7291 also, you should check your codes, the Electronic Control Unit (ECU) will typically point at the issue. But below is a good link to test that TPS. easyautodiagnostics.com/ford/4.9L-5.0L-5.8L/throttle-position-sensor-tests-1

[@TheBadasspony]

does this affect the fuel pressure ?

[@jpp9846]

My Understanding is no. It simply just gives the ECU a reading on what the Manifold pressure is. If it's wrong, then your ECU gets the wrong info and may send the wrong fuel ratio out.

[@shelbydaytona]

My map air connection has plug is that normal ?

[@jpp9846]

Not if it's an 86-88 Speed Density, it should be linked to your Intake Manifold. If it is an 87-88, and has been swapped to Mass Air (they'll be a sensor on the air, intake tube(, then the MAP sensor is now a BAP sensor and must be unplugged and "open".

[@awh5773]

that MAP sensor ford put on everything they made back then. trucks , vans , cars all motors that i can tell. i been having problems with my 1988 f250 5.8L for a long time now. i have both the new blue and old red haynes repair manuals . i do what the books say about testing them damn MAP sensors. the orange wire gets 5 volts constant. the green wire gets 5 volts with connector unplugged. but as soon as i plug the connector back onto the sensor. that damn green signal wire goes straight to 2.5 volts (koeo). i put a vacuum to it and it wont come off that 2.5 volts . the book says it is supposed to be 5 volts then add vacuum to 20hg and the voltage is supposed to drop to 1 volt. i have disconnected the computer from the harness and checked pin 45 at computer harness connector all the way to the map sensor connector green wire. it aint broke or cut or burnt or corroded. that green signal wire is like it is supposed to be. i have changed out the ecu / computer 2 times and that damn map sensor about 6 times and finally got a brand new motorcraft one and it still reads 2.5 volts at the green signal wire. what the hell am i missing???? i even soldered in a new pig tail connector for the map sensor just in case the connector may have had a problem. it runs a little rough but it acts like it is actually trying to learn to run because it sounds different when it is running. and i have thrown the parts canon at it. all sensors check out like they are supposed to except for that damn map sensor. also new plugs, wires , cap and rotor and coil and the timing is right on the money. at 70 mph she runs smooth as glass but at idle she runs a little rough . and the computer code reader is not throwing any codes. the only thing i can think of are the injectors, but none of the plugs are wet or have any carbon build up on them they are greyish / redish color like they supposed to be. has anyone run into this problem???? p.s. 5.8L only has about or just under 10,000 miles on it also made smoke machine and fixed all vacuum leaks and replaced all 3 fuel pumps and fuel regulator. also replaced the EGR valve with new one 2 days ago. im totally lost??????? i have been told that these ford motors in cars and trucks takes from 1 to 2 weeks to learn how to run right after you remove the battery cables for a while. is that true???

[@jpp9846]

Sorry buddy, but this one here is specific to the 5.0 Mustang. I'm honestly not privy to the 5.8 f250. But I can say, that within a day or two, the ECU (computer) adapts to the changes, if not sooner. My original thought was "pull the codes", but you did that. I don't think it's your MAP. But I can't point you in the right direction on a F250. I've learned my Mustang and unfortunately , my"knowledge" ends there

[@brandonknight7240]

My 88 is running like shit especially at startup, but it has the 89 computer and i dont know if its still speed density or not

[@jpp9846]

Does it have a meter on the air intake tube? If it does, it's likely.been converted to Mass Air.

[@hotrodray6802]

Replace the water temperature sensor in the heater hose with a Motorcraft part. It is giving the computer a false reading

[@chrisfenton537]

I have an 88 gt if I hook the vaccum line up my spits and pops and backfires ..what could the problem be ..? The runs real rich also now

[@jpp9846]

If you hook your vacuum line where? Which line?? That could be a few things. Are you able to pull codes? I'd start there.

[@chrisfenton537]

If I hook the vaccum line from my intake to the map sensor and drive down the road the car runs like crap ,if I leave it unhooked it rough idles and runs rich car has power

[@jpp9846]

@@chrisfenton537 I know the 89+ cars that are Mass Air Flow, require the MAP (called a BAP in 89+ cars) to NOT be vacuumed. Has your car been converted to MAF (does it have a sensor on the air tube)? Can you pull codes?? Where is your timing set??

[@chrisfenton537]

@@jpp9846 aftermarket cold air intake no wires or connection for maf ..timing is about 12 degrees no way to pull any codes no lights on !!

[@jpp9846]

@@chrisfenton537 have you tried to pull timing back a little? I only mention timing because if too far advanced it will run rich and crappy... But I think 12 isn't too bad. Something to try. I think Walmart sells an OBD1 scanners for $20. It has the code book too. This doesn't necessarily give you the answer, but will point you to something. What you describe can be a few things. Timing, vacuum leak, bad TFI module, could also be bad O2 sensors. What I've learned, most of the time these cars have issues, it has something to do with sensors. When they're bad, or failing, they send bad info to the Engine Control Unit (computer in the passenger kick plate). It also could be something not working correctly inside that computer too. I'm sorry I can't give you a great answer. These dam fox's are a labor of love. I've had fits in my garage over it. But I now know my car because of the time I've spent with it. One other thing does come to mind, have you changed your fuel filter lately? Or know how old it is??