Driveability Issues after 4.6 Install
Posted: July 10th, 2020, 8:17 am
So I finally got my stroker installed after an entire year fiddle-f**king around, got it running and having some stupid problems.
No codes being thrown at this time.
1. Starts up fine, when first driving after anywhere from 15 seconds to 1 minute it sputters and loses power. I have to pull off the road and let it idle for 15-30 seconds, seems to help if I rev it a bit during this exercise. Then it returns to 'normal' and doesn't do it again until it's shut off and restarted. Even if I shut it down for just 1-2 minutes it does the same thing again in the same time range, so I don't see how this could be anything other than a computer/sensor issue.
2. Randomly elevated idle- this happens about 2 out 3 times it's driven. It'll idle normally around 800rpm, then out of nowhere the idle will be at 1200, 1500 and as much as 2000rpm. This will happen after driving for a few minutes and will just keep happening....after sitting at idle it will drop back down to 800rpm (but not always). No vacuum leaks.
3. Seems to miss a little at idle. Could this just be the cam? All electrical components are new including the distributor.
4. Not very smooth through the RPM range- even when it's running normally it seems to take off well but gets a little sluggish and jerky between 2500 and 3000 rpm. This is slight but noticeable.
The build is .030 over pistons, 4.2 rods with a CompCams 252 cam. It ran normally before I broke a piston and pulled the engine last year.
I'm planning to upgrade the injectors and fuel pump, not sure what else I ought to do. Confusing since I'm not getting codes and this really seems like it must be related to the computer and/or possibly MAP, IAC or something of that ilk.
No codes being thrown at this time.
1. Starts up fine, when first driving after anywhere from 15 seconds to 1 minute it sputters and loses power. I have to pull off the road and let it idle for 15-30 seconds, seems to help if I rev it a bit during this exercise. Then it returns to 'normal' and doesn't do it again until it's shut off and restarted. Even if I shut it down for just 1-2 minutes it does the same thing again in the same time range, so I don't see how this could be anything other than a computer/sensor issue.
2. Randomly elevated idle- this happens about 2 out 3 times it's driven. It'll idle normally around 800rpm, then out of nowhere the idle will be at 1200, 1500 and as much as 2000rpm. This will happen after driving for a few minutes and will just keep happening....after sitting at idle it will drop back down to 800rpm (but not always). No vacuum leaks.
3. Seems to miss a little at idle. Could this just be the cam? All electrical components are new including the distributor.
4. Not very smooth through the RPM range- even when it's running normally it seems to take off well but gets a little sluggish and jerky between 2500 and 3000 rpm. This is slight but noticeable.
The build is .030 over pistons, 4.2 rods with a CompCams 252 cam. It ran normally before I broke a piston and pulled the engine last year.
I'm planning to upgrade the injectors and fuel pump, not sure what else I ought to do. Confusing since I'm not getting codes and this really seems like it must be related to the computer and/or possibly MAP, IAC or something of that ilk.