Sorry, this is the first time I've used the forum and I'm probably doing it wrong. But here's my problem I have a 1988 bronco for 302 and the automatic overdrive transmission and it dies whenever I go on the highway or rev over 3000 RPM for any duration of time. So far I've replaced the map sensor EGR valve, both fuel pumps, fuel pressure regulator and put a completely new distributor with ignition module. I am a do it yourself type of person and taking it to a mechanic is admitting failure but I have no clue what else could cause the problem. Any help or ideas would be very much appreciated.
Bronco dies on High way or RPM over 3,000
- Thread starter Fink
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
Yo Fink,
Welcome!
Try a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19@
http://broncozone.com/topic/14269-code-reader/?pid=74587&mode=threaded
Some basics;
The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test.
Run it around to heat the engine up and shift thru all gears including Reverse.
Make sure A/C is off and transmission is in Park (automatic); or in Neutral for a Manual & release clutch.
Then turn off engine, all accessories/lights (close driver's door) , etc.
Do KOEO test First
Post Code(s) here according to:
KOEO
&
KOER
...
Some no code usual suspects by Ford;
Vacuum leak, see my leak diagnosis link in post #20 @
http://broncozone.com/topic/23994-90-58l-getting-continuous-code-33-and-running-code-44/?p=125535
Air filter, is it relatively clean?
Air inlet atop radiator support to filter box and to throttle body; look for obstruction; damaged tubing
Fuel quality; Oxidized fuel often turns darker over time and may even smell sour. You can check stored gasoline by pouring some into a clear glass container and comparing it side-by-side with known fresh gasoline. If your old sample looks noticeably darker than the fresh gas, you have strong evidence the gas has gone bad.
Electrical connectors; inspect at ignition control module (ICM), coil, PCM, etc. especially those with broken locking tabs.
...
ICMs are know to intermittently faio due to heat because of its location. Location pic at distributor;
by Handy_andy_cv64 (Ed B)
ICM Relocation & Modified Mount in an 86
Source: by broncAR (Rodolfo Mario N) @
http://www.supermotors.net/registry/7287/60637-2
Excerpts; "...My rig has suffered HWB (Hot Weather Bug) since I got her. My TFI-PIP assembly just doesn't like hot weather. During winter everything is OK, but as soon as temperature rises above 86 degrees I have problems. I made a patch and problem was solved at highway speeds but at lower speeds the bug attacked again. So I decided to go for the remote TFI module location. I read several write-ups in this and other forums (John Olds write up, csn.rebel write up , TFI ground discussion), I asked some questionsand finally came to what I think will be a solution. The main problem to my opinion is the harness to connect the module to the distributor, so I came up with this:
I decided to use an old TFI module as plug to the distributor. I think that way the distributor will be as isolated from dust and moisture as OEM. So I opened the TFI ..." read more
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)..."
by therangerstation
But sometimes a code does not cause check engine lamp to glow.
Use a Motorcraft ICM, DY1074 (supercedes DY425)
Ford - 5U2J-12A297-AA, 5U2Z-12A297-A
Wells - F121
https://www.amazon.com/Ford-5u2j-12a297-aa-5u2z-12a297-ignition-module/dp/B00OBU492A
...
Next time, please fill out your Signature with year, engine size, transmission type, transfer case type (manual or electric shift), locking hub type (automatic or manual) info & major mods such as a Lift, etc. for better responses.
Click your name in right black panel in upper right;
In pop up,
Click, My Profile
Click, Edit My Profile in right side black panel
In left panel, Click, Edit Signature
Enter info
Click, Save Changes
...
To post a pic from your PC, TABLET, etc., just below the reply box in lower right corner, click More Reply Options
Screen will change
See Attach files
pick out the pic
Click Attach This File
or click, Try our advanced uploader (requires Flash 9)
...
Keep each post limited to one issue as you have done here.
...
Our sponsor, Jeff at the Bronco Graveyard has offered a 2% discount to members of The BroncoZone for on line orders. To get your discount, enter the discount code BZMEMBER. Also you must include your BroncoZone User Name with the order.
http://broncograveyard.com
Here are some wiring diagrams (partial, 86 through 96) and Technical Service Bulletins, (80 through 96) @ http://www.revbase.com/BBBMotor/Wd
Welcome!
Try a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19@
http://broncozone.com/topic/14269-code-reader/?pid=74587&mode=threaded
Some basics;
The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test.
Run it around to heat the engine up and shift thru all gears including Reverse.
Make sure A/C is off and transmission is in Park (automatic); or in Neutral for a Manual & release clutch.
Then turn off engine, all accessories/lights (close driver's door) , etc.
Do KOEO test First
Post Code(s) here according to:
KOEO
&
KOER
...
Some no code usual suspects by Ford;
Vacuum leak, see my leak diagnosis link in post #20 @
http://broncozone.com/topic/23994-90-58l-getting-continuous-code-33-and-running-code-44/?p=125535
Air filter, is it relatively clean?
Air inlet atop radiator support to filter box and to throttle body; look for obstruction; damaged tubing
Fuel quality; Oxidized fuel often turns darker over time and may even smell sour. You can check stored gasoline by pouring some into a clear glass container and comparing it side-by-side with known fresh gasoline. If your old sample looks noticeably darker than the fresh gas, you have strong evidence the gas has gone bad.
Electrical connectors; inspect at ignition control module (ICM), coil, PCM, etc. especially those with broken locking tabs.
...
ICMs are know to intermittently faio due to heat because of its location. Location pic at distributor;
by Handy_andy_cv64 (Ed B)
ICM Relocation & Modified Mount in an 86
Source: by broncAR (Rodolfo Mario N) @
http://www.supermotors.net/registry/7287/60637-2
Excerpts; "...My rig has suffered HWB (Hot Weather Bug) since I got her. My TFI-PIP assembly just doesn't like hot weather. During winter everything is OK, but as soon as temperature rises above 86 degrees I have problems. I made a patch and problem was solved at highway speeds but at lower speeds the bug attacked again. So I decided to go for the remote TFI module location. I read several write-ups in this and other forums (John Olds write up, csn.rebel write up , TFI ground discussion), I asked some questionsand finally came to what I think will be a solution. The main problem to my opinion is the harness to connect the module to the distributor, so I came up with this:
I decided to use an old TFI module as plug to the distributor. I think that way the distributor will be as isolated from dust and moisture as OEM. So I opened the TFI ..." read more
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)..."
by therangerstation
But sometimes a code does not cause check engine lamp to glow.
Use a Motorcraft ICM, DY1074 (supercedes DY425)
Ford - 5U2J-12A297-AA, 5U2Z-12A297-A
Wells - F121
https://www.amazon.com/Ford-5u2j-12a297-aa-5u2z-12a297-ignition-module/dp/B00OBU492A
...
Next time, please fill out your Signature with year, engine size, transmission type, transfer case type (manual or electric shift), locking hub type (automatic or manual) info & major mods such as a Lift, etc. for better responses.
Click your name in right black panel in upper right;
In pop up,
Click, My Profile
Click, Edit My Profile in right side black panel
In left panel, Click, Edit Signature
Enter info
Click, Save Changes
...
To post a pic from your PC, TABLET, etc., just below the reply box in lower right corner, click More Reply Options
Screen will change
See Attach files
pick out the pic
Click Attach This File
or click, Try our advanced uploader (requires Flash 9)
...
Keep each post limited to one issue as you have done here.
...
Our sponsor, Jeff at the Bronco Graveyard has offered a 2% discount to members of The BroncoZone for on line orders. To get your discount, enter the discount code BZMEMBER. Also you must include your BroncoZone User Name with the order.
http://broncograveyard.com
Here are some wiring diagrams (partial, 86 through 96) and Technical Service Bulletins, (80 through 96) @ http://www.revbase.com/BBBMotor/Wd
Similar threads
