I just picked my 87 bronco ll 4x4 2.9 (85k miles) up from the shop yesterday and its still idling funny after I got it home.When I crank it up it is slow to crank, then the truck idles at 3k rpm for 10 secs, drops to 2k then drops low like its go to cut off-a flash of check engine light, shoots way up then way down a few times then dies. When I drive it, the moment i start to break the car trembles like its going to cut off but when I come to a stop the rpms jerk back up again.I dont even have to come to a complete stop, if i press the break pedal at all the cars starts to act like its going to die.It is also getting poor gas mileage, poor power and SLAMS into gear intermittantly.
Prior to the work it would cut off and sputter and chug, so its better but still the same.
This is what Ive had done: Major tune up,Replaced EGR and cleaned EGR ports, o2 sensor, map sensor, both fuel filters and o ring, and Cat converter.
These are the codes i got before repair: code 41-bank not switching, code33- insficcient EGR flow and code 13 cant control RPM/LOW.
Any help would be great.After 1k and a garauntee that these would fix the problem i am stumped

 

i feel for you. its so frustrating to get so far and each thing you change is a let down. could it be related to a vacuum problem? do these engine shave a maf unit? (mass air flow) if a maf was faulty it would the same thing as you describe. but then so would ten oher problems. im not much help i know but trying to give you some other ideas.

 

I am sure its vacuum related, your brake booster uses vacuum. Check for correct vauum with a guage. Autozone.com gives good specs for free on older vehicles. Listen for leaks. Better hope its not a cracked head. Check each head with a vacuum guage. Just disable fuel or spark, remove 1 plug at a time for each test. then insert guage into plug port, turn engine over while looking at pressure. Again get specs for correct vacuum.

 

i had a vacuum issue on a vw golf last year and a mechanic friend of mine came over to fix the problem. he used wd-40 (im sure you guys get that in the states) and sprayed it close to each vacuum pipe with the engine idling. as soon as he sprayed close to the leak the engine note changed and hey presto a new pipe was fitted. its cured the problem ever since. although not sure if you can get yours to idle

Dan

 

I think it is probably the TFI module, I had driveablity problems like that when mine went bad and it did not even throw a code. Pretty much a defective design on the TFI, so I use to carrry a spare in my glove box along with the tool (1/4 ratchet and socket) to change it. The WELLS is only $30 and is exactly the same as the more expensive ones, so save money and pop one on. If not defective, it will be.

That being said, I think it is worth the time and money.