I'm lost!

[A-drain]

I was wondering if anyone else on here has ever ran into this problem and knows what it is. Just yesterday my 84 marqee started surging bad at idle. Know when I let idle I'll give gas and it will sputter then rev up an then when it comes back down from revving it slowly chokes and then dies... I have recently replace the fuel pump and the tps thinking it was the tps however the problem continues. I have also tried one of my spare tfi modules and same problem. Any one know what it is? Also it's a cfi 5.0

[A-drain]

It also smells bad like gas. Not so much raw gas like pumping at a gas station but more like a lawnmower that's choked up... Fuel pressure regulator?

[DerekTheGreat]

CFI.. Pop that throttle body and EGR off and clean all of the built up carbon in those passages. My '85 wouldn't idle well either, and surged much like you mentioned until all that was cleaned up.

[A-drain]

It just started all of a sudden too. I hope no one poured something in the gas tank...
Passages being? The two bored where the injectors are? Also I got rid of the egr so all I have where it is suppose to go is a solid plate with a gasket sealing it.

[DerekTheGreat]

OH, well then.. I suggested the EGR because typically those passages get all gunky and the pintle on the EGR valve can stick open and cause what you've described. But, since you've eliminated all of that my best guess is perhaps you've got a vacuum leak somewhere.. When did you last change the fuel filter? What's your fuel pressure? No idea what CFI cars run at but someone on here probably does and that is pretty easy to check.

[gadget73]

I'm voting for vacuum leak if the EGR isn't stuck open. The line to the MAP is very important.

[sly]

Doesn't it have a type of choke like a carb? Might check to make sure that's not closing too much or staying way open.

[DerekTheGreat]

Doesn't it have a type of choke like a carb? Might check to make sure that's not closing too much or staying way open.

If the 84 and older ones are anything like my 85 then they've got a choke like mechanism which catches the throttle and holds it open a bit more than the standard idle. Stupid BS that never works right. Hey wait... Yeah, is your car hot or cold when it's acting up like this? If it's cold then it could be that your choke pull-off needs to be adjusted. My car would idle goofy when cold if either I didn't hold the throttle or let the choke-pull off do it. I remember the sticker on the core support said the cold idle should be ~2,100rpm but I got away with ~1,600 IIRC. 2,100 is just way too high for me to feel comfortable dropping it in gear.

[A-drain]

It completely shuts off when cold. When warmed up it chokes about to die comes back up chokes and sometimes dies. I changed the fuel filter when I changed the pump about a week ago. Rented out a pressure test and just my luck it was missing the adapter for the ford Schader valve.

[A-drain]

Also when I drive it I could give it 3/4 gas and it'll will not accelerate at first I thought it was the transmission that's how bad it was.. In neutral I'll rev up to 1000 rpms and try to hold it there but it will not stay steady and fluctuates like crazy. Go up to about 2500 rpms and it'll hold steady.

[DerekTheGreat]

Certainly seems like a fuel delivery issue or spark issue. You can check the pressure with any ole tire pressure gauge. If you use one of the stick type ones it will be garbage after but at least you'll have your answer.. A lil fuel will spray up of course so have rags ready. While you're there, check the vacuum line to the MAP sensor like gadget mentioned and maybe even try swapping that out if the line is fine.

[His Royal Ghostliness]

The CFI system is way too dependant on proper vacuum signals, and there are entirely too many vacuum lines on these engines, and 90% of them are routed in a most stupid way. Hate to say this, but pop your air cleaner assembly off, and start tracing EVERYTHING back there. If anything looks questionable just run a complete new line. While you're at it, elliminate all the T-ees that have capped-off ports and 2" long connecting hoses - you'll see what I'm talking about when you start digging into it, it's a clusterfawk to say the least, and from a functionality standpoint it makes exactly zero sense to have all that junk the way the factory set it up.

[A-drain]

Update.. Day two.
So I changed the fuel pressure regulator last night and same symptoms. So I traces the hose to the map like many suggested. And I replaced it with the old map sensor I had... And the symptoms got worse! So decided to order a new one. I hook it up this morning and the car doesn't even crank over. I put the old one in and it starts. But I think it's the connector not making a connection to the new one. It's all corroded and doenst even clip cuz the plastic broke. So I ordered a new one that imma solder in. Unfortunatly it does not come in till tomorrow....

[DerekTheGreat]

Cool, looks like you might have this all figured out now. Let us know if it solves the issue.

[sly]

That would do it. with no MAP signal it goes into a uber stupid mode and generally doesn't work.