Bronco.Shuts.Off - Dangerous!

[*broncoXLT]

Hi all-

So I'm in an odd situation. My bronco is shutting off while I'm driving it- literally just shutting off. It's like you just turn the switch off. I lose total power (scary when it happens going 50 mph) at any speed. It happens randomly from day to day. I coast to the side of the road, put the truck in park and it fires right back up like normal. It will not start in neutral.

I recently pulled the engine and put all new gaskets in, along with a distributor, pcv valve, vacuum lines, plugs, wires and a starter. It ran great for about a week, then my negative terminal had to be replaced. It was consistently losing connection and the truck wouldn't start unless you wiggled the cable. It's fixed and good to go now.
I have checked fuel pressure and its good. I have replaced the ignition module. There are no codes coming up. I've tried pulling any right after the shut offs happen as well. I replaced the pick up in the distributor just in case. All parts in the ignition system are new and replaced.
I've been all over this truck and tested everything possible. I need it to haul my horses, but certainly not right now with it randomly shutting off.

So what's my next option? Maybe the computer is bad? Or I have a bad ground somewhere? Could the terminal losing connection and then getting connection a number of times have fried something in the computer?

I'm at a loss. Please help /emoticons/[email protected] 2x" width="20" height="20" /> /emoticons/[email protected] 2x" width="20" height="20" /> Most ideas appreciated /emoticons/[email protected] 2x" width="20" height="20" />

 

[*broncoXLT]

It was also throwing codes 11 and 18 KOER.

I checked the SPOUT and its clean and snug.

 

[miesk5]

yo Bronco XLT,

11 System PASS

18 KOER - SPOUT circuit open

18 Continuous Memory (CM) -  IDM circuit failure or SPOUT circuit grounded.

KOER OK, so we can assume SPOUT is secure and good electrically; one test is to pull it &  check it for 0 ohms; if NG, replace w/suitably sized copper wire

I am posting this TSB in case someone mentions that there is a TSB out on Code 18;

DTC 18 in KOER TSB 87-24-17 in 88 Bronco, E & F Series 4.9L
Source: by Genco http://www.revbase.com/BBBMOTOR/TSb/DownloadPdf?id=21803
.....

CM:

DTC 18 IDM circuit failure or SPOUT circuit grounded

Source: by Ford via Ben Watson in How to Tune and Modify Ford Fuel Injection via books.google.com

http://books.google.com/books?id=-9W2U2fgp6IC&pg=PA79&lpg=PA79&dq=Code+18++ford&source=bl&ots=eaTeuXT5XE&sig=bR8lCPhsvmSpK9pqKqWD0vj89v8&hl=en&ei=7Le6Tb_0M9OBtgeps9DZBQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBgQ6AEwADgU#v=onepage&q=Code%2018%20%20ford&f=false

Ben doesn't mention that the wires leading to and from the SPOUTconnector can ground or or are cut by the foil shield

Foil shield  covers the wires to and from the Ignition Control Module (ICM) as well as the SPOUT circuit.
 

DTC 18 IDM circuit failure or SPOUT circuit grounded; "...The computer sends out a timing advance correction to the ICM over the SPOUT wire and then looks for the change on the IDM wire. You might check the ECT or the IAT sensor for your problem. Also check the SPOUT/IDM wire going to ground..."
Source: by freeautomechanic.com DTC 18 or 212; Ignition Diagnostic Monitor (IDM) Troubleshooting; "...Identifying the correct module for your vehicle can be accomplished in a number of ways. First, always refer to the correct application in the Engine Management catalog. If that information is not available, check the wiring of the vehicle. If pin # 4 of the module gets a start signal (which should be battery voltage) from the starter circuit, it's a "Push Start" system. On the other hand, if pin #4 of the module is wired directly to pin #4 of the ECM, then it's a CCD system (refer to diagram #5)..." READ MUCH MORE Miesk5 NOTE; use BLACK CCD Ignition Modules in 94-96 Broncos  Other years use the Gray Module
Source: by Joe D at carquest.com
DTC 14 & 18; Profile Ignition Pickup (PIP) & Troubleshooting; "...The top three leads (for PIP signal) can lose continuity with the back plate (ground) on the module when the unit is hot. You should consider a remote mounted TFI. If your TFI is failing from heat, it can give off computer codes 14 (PIP) and 18 (SPOUT). stalling/dieing or sputtering when hot but runs when it cools off. This can be caused by a faulty TFI and the biggest culprits are heat. Another culprit can be a wire grounding out. Problematic TFI's can give off codes 14 (PIP) and 18 (SPOUT)..." read more

---------------

Thick Film Ignition (TFI) Troubleshooting Worksheet; miesk5 Note; this is the Grey Module
Source: by SeattleFSB (Seattle FSB) at SuperMotors.net

This is the best wiring diagram I could obatin for a 1988

Wiring Diagram, TFI in an 88
http://ylobronc.users.superford.org/documents/ignition.gif
Source: by Dustin S (Dustball, Mellow Yellow, Mr. Laser Boy) at ylobronc.users.superford.org
SPOUT IS LABELED AS SHORTING PLUG
FOIL SHIELD IS LABELED AS SHIELD
Y/LG wires need to be checked

 

[*broncoXLT]

Update: I tried to bypass the ignition system by connecting a wire from the positive battery terminal to the coil. It made the truck run more rough and it still had died.

I then bypassed the ecc relay and the truck ran like a top. However, after driving for roughly 10 mins, it once again shut off (in a parking lot thank goodness).

I'm really really at the end of my rope. I just don't know what else to do /emoticons/[email protected] 2x" width="20" height="20" />

Thanks for all the help everyone!
__________________

 

[inkedairman]

I have a similar issue(95 Eddie Bauer 302) like that while driving. My bronco shut off and then a couple seconds later it was back on(By the time I had a chance to really notice what was happening). I haven't dug into anything yet but plan to this weekend and check on wires. If you find anything I would like to know as well.

 

[Seabronc]

95% chance that it is either the TFI module or the pickup inside the distributor.  I'd put my money on the pickup as that is a classic symptom of a pickup shorting out when it gets hot but works when cool.

Good luck,

>-