• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

engine revs/runs rough


scoutbuff

New Member
Joined
Feb 28, 2015
Messages
2
Reaction score
0
Points
0
Vehicle Year
1988
Make / Model
FORD
Transmission
Manual
So I have a 88 Bronco ii. It has a newer motor with about 15k on it. Since the swap it has done a weird run/miss part way thru warm up. It feels like it not getting spark or something. It doesn't do it cold or completely warmed up. only about 1/4 way warmed up. If in a hurry to drive it can hardly get out of it's own way and barely accelerates. It has a complete tune up on it. to include plugs, wires, cap, rotor, fuel filter, oil change. Yet it doesn't change anything. At a loss and need some ideas. :icon_confused:
 


RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,363
Reaction score
8,367
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Fuel injected engines can't use a Choke plate, no jets to suck extra fuel from, but a cold engine needs more fuel, richer air/fuel mix, to stay running.
So all fuel injected engines have an ECT sensor, engine coolant temp sensor.
This is similar to the 1 wire temp SENDER used on all water cooled engines to run a temp gauge, but the ECT is a 2 wire SENSOR only used by the computer.

Computer sends ECT sensor 5volts on 1 wire then gets back 4 to .5volts on the other.
3volts is cold, under 1 volt is warmed up
If your ECT sensor is reporting cold engine(3v), as it should, when engine is cold but then jumps to under 1volt before engine is warmed up then engine would struggle to stay running until it did warm up.
You can test these with a volt meter, but you can also buy a new one for $7, so.........
 
You must log in or register to reply here.

Sponsored Ad


Sponsored Ad

Staff online

Members online

Total: 292 (members: 6, guests: 286)

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Latest posts

Truck of The Month


Shran
April Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

Latest Album Photos

20240409_190831.jpg
20240409_190818.jpg
20240409_180824.jpg
20240409_182648.jpg
20240409_181010.jpg
20240408_175026.jpg
99 Ranger
20200706_161414.jpg
20240207_155117.jpg
20240207_155111.jpg
20240207_154537 - Copy.jpg
20240207_154500 - Copy.jpg

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top