What would cause?

[VicCrownVic]

That's it there. ^

[Toploader]

Vic, would this picture be close to te same on my '86 5.0?

[ATTACH=CONFIG]39060[/ATTACH]
That's it there. ^

[Toploader]

Neon, more things for me to check out, which I will as soon as get to the shop....!!

ya ...it could....especially if you have a weak collapsing vacuum hose, and or weak motor mounts....what happens is the motor,in gear, rocks on the mounts and either pinches the hose , or opens up a small split in the hose, causing a vacuum loss. therefore, the sensor reads wrong and poof.....it dies...or runs like crap, etc..... the hose runs from the sensor(mounted on the passenger side firewall or inner fenderwell) to the intake manifold under the intake plenum at the rear next to the firewall....and yes , its a bitch to get you hands back there, but if its never ben replaced, I would replace it, worse comes to worse, it should only cost a few bucks, and would at least knock one thing off the list of possibilities. the MAP sensor itself ususally doesn't go bad, but for diagnostic purposes, if you know someone who has a good spare, changing it out to see if it makes any difference wouldn't be a bad idea either (I wouldn't go buy a new one unless you have evidence that it is bad)....hope this helps.

[VicCrownVic]

Vic, would this picture be close to te same on my '86 5.0?

Sorry, I would imagine it is the same on an 86, but don't know for sure. I know it is correct for 88+, that's a pic from my 91 MGM.

[Toploader]

No problem, just found my '86 Electrical & Vacuum trouble shooting book, your picture is close to the same, different position, I'll find it, thanks!

Sorry, I would imagine it is the same on an 86, but don't know for sure. I know it is correct for 88+, that's a pic from my 91 MGM.

[91waggin]

I have had a bad MAP cause surging in drive and not in park or neutral. MAP senses engine load. Engine load changes when you put car in D because the torque converter puts drag on the motor. That's why it idles down slightly when you put it in gear.

Originally for me it started as surging at idle in gear, then it progressively got worse, and finally the damn thing would start and stall immediately, and would make lots of black smoke because it was running so rich. Took me forever to diagnose that bastard.

But people above me are definitely right. The vacuum hose from intake to MAP can get really spongy and nasty and gross. It lives in a rough part of town.

[Toploader]

Waggin,
Can not tell what these posts do for me, jeeze it's better-n-sex!...........well er, not really but close!
I will change the hose and see then the MAP

[gadget73]

Vic, would this picture be close to te same on my '86 5.0?

Yes, but its mounted facing outward on an 86, not under the bracket like 88+. same location and sensor though.

[Toploader]

So many FoMoCo numbers that seem to cover the same vehicle?........I pulled this off the car today: E6EF-9F-479A1A. Also found the following numbers which claim to be the same??: E6PZ-9F479-A And E7DZ-9F-479-A. Why does Ford change numbers of basically the same part???

Yes, but its mounted facing outward on an 86, not under the bracket like 88+. same location and sensor though.

[gadget73]

engineering revisions and other things. I've never paid any mind to it, if it looks the same, it is the same. The MAPs are all the same electrically as far as I've ever been aware.

[Toploader]

Excellent, off to secure one if needed after the hose replacement

[91waggin]

Waggin,
Can not tell what these posts do for me, jeeze it's better-n-sex!...........well er, not really but close!
I will change the hose and see then the MAP

[Toploader]

I hope it is only the hose, a new MAP is like a hundred dollars.........(NOS FoMoCo)

[gadget73]

you can buy new parts? What? I usually just wander around the junkyard and grab a stack of the things. They don't go bad all that often.

[Toploader]

Gadget, I live in NYC, and the last I looked there were zero salvage yards here! Back in the day I did travel to Washington NJ, to a place called Kobers Auto Salvage.........an amazing place!! Never failed to find what I needed!, even doors and bumpers for my '67 500 XL! But for now, I have to troll the net for places like Green Sales, NOS Ford, and AUP. Yes I have found some stuff at Deer Valley Parts in Arizona, but only seat belts, and some hard parts. And if I am going to need a MAP I would feel better getting new, as opposed to one pulled off a junk car! For now my thoughts are just getting guys together for a box meet up, soon!!!!!

you can buy new parts? What? I usually just wander around the junkyard and grab a stack of the things. They don't go bad all that often.