fx4wannabe
Full Access Member
Pump timing also has a lot to do with it. I was shocked how much better she ran when I bumped the timing a degree or so.
travis-So, here's what I've gathered;
healthy engine to start with
good inj pump
good injectors
timing at or about 9.5
turbo
free flowing intake and exhaust
Optional;
intercooler (good idea for towing)
Type4 cam (sounds good, but lots of work unless already apart)
Aside from the optional items, is this about it for a strong running IDI? Have I left anything out? What's the best place to start if it doesn't run like others with the same equipment? Assuming a healthy engine, the injection pump probably has the most effect on economy and driveability, right?
Travis..
So, here's what I've gathered;
healthy engine to start with
good inj pump
good injectors
timing at or about 9.5
turbo
free flowing intake and exhaust
Optional;
intercooler (good idea for towing)
Type4 cam (sounds good, but lots of work unless already apart)
Aside from the optional items, is this about it for a strong running IDI? Have I left anything out? What's the best place to start if it doesn't run like others with the same equipment? Assuming a healthy engine, the injection pump probably has the most effect on economy and driveability, right?
Travis..
If a guy were doing a rebuild, a cam and ported heads, etc would be a no brainer. I'm not talking max output, no more left on the table here, I'm talking what's the best way to get decent power from a runner. I know some engines run better than others from the git go, even identical stockers. It would be nice to see some of the trucks that claim low power to be able to make them better and closer to expectations. I thoroughly understand the comments about a small block gasser outperforming an IDI with exception to fuel mileage. BUT, I also don't think that should be the case. A diesel with a turbo should not pull the same as a small gas engine, IDI or not.
Travis..
A fresh fuel system make a huge difference!
Pump timing also has a lot to do with it. I was shocked how much better she ran when I bumped the timing a degree or so.
This is a common response. Performance of the IDI trails off so slowly over time it is not perceptable to the driver. What usually happens is years later, they think "This truck seemed to have more power years ago, but maybe that's just me romancing my memory". Most will not do a voluntary "tune up" which consists of refreshing the fuel system, because "it runs great!". Yet in reality a voluntary replacment of IP and injectors every 100,000 miles (what I would consider a maximum service life... 50 to 75K would be a much better interval) is really what is needed. I've observed that injectors loose their optimimum pop presure within the first 10,000 miles, so things really go down hill a lot faster than you might think.