ive got a 78 f100 with the 300 6 in it and it runs very well when your driving it but it idles terrible...misses very bad and diesels when you kill it i have to put it in gear and let out on the clutch just to get it to shut off....heres what i have done,ive set the timing,new plugs and wires cap and rotor, fixed several vacuum leaks, pulled all the emissions bs off of it not that there was much to it in the first place,tried tuning the carb but dont think it made much of a difference so now my last opyion is rebuilding the carb...what does it sound like to you guys? another thing ,how can i get rid of the egr plate and go back with a regular spacer...maybe off a 60's or early 70's model truck with a 6 cyl?

 

What all, and how, did you check for vacuum leaks? You need to put a vacuum gauge on it. Does the vacuum gauge respond to changes in the idle mixture screw?

This is why it's dieseling when you shut it off. EGR motors from the factory are tuned differently to compensate for the altered combustion chemistry that comes with EGR. If you simply remove the EGR system and don't re-compensate, the engine is left running lean and over-advanced. This keeps the combustion chamber temperatures very high, leading to dieseling and pinging. You either need to re-curve your distributor and richen your jets, or put the EGR system back. There is NO reason to remove the EGR system, other than for aesthetics. Even if you were to tune it back to health, it would only run as well as it did before. There are no performance gains from removing a properly functioning EGR system; you may actually see a subtle drop in fuel economy without it.

It sounds like a misinformed person told you that "smog junk" is bad.

You shouldn't. Also note that there is a long pipe that goes from your exhaust manifold to said spacer and there's no way it's coming off.

 

FMC400, he can remove the egr by changing the intake and exhaust manifolds to some efi units and an offy DP

Just saying would be a win win aside from his pocket book.

 

That's another solution and happens to be what I did (I installed a Hedman header instead of the EFI manifolds), but for a different reason.

 

I've heard Alot about the offy stuff but thought it was mainly for high performance and that's not my plans for this truck however how much roughly would the intake cost? Fmc400 you mentioned me being Mis informed about emissions being bad, in my opinion they are bad on a carbuerated engine,9 times out of 10 half the components are missing or are malfunctioning and they run terrible like in my case now so by removing them like I've always done and plugging off vacuum ports,retuning your carb and adjusting your timing (it's usually always set a little fast in past experiences) they run drastically better and the fuel economy increases slightly but in this case it hasn't improved anything so that's why I asked you guys to see if I was missing anything because when I've always done this it was on a Windsor v8 and I'm sure this 6cyl is a different animal

 

What does that mean?

 

I'm doing this on a smartphone and auto correct is a pain in the **** lol

 

Sorry, that wasn't really meant as a personal attack.

I disagree with this generalization. Either way, as you pointed out, removing emissions equipment actually caused more issues for you in this situation.

 

Offy intake runs 260 on summit i think, but you can find them used as well, Carbs are 290 for 500cfm edelbrock, or 390 for a holley 390.

Picked up my offy and 390 shipped for $360.

 

@ fmc400 I didn't take that as a personal attack you were just simply stating your opinion and I appreciate that, we all have our own opinions and ideas...you do, I do and so does everyone else on here and that's great because if we all had the same ideas and opinions we would never get anything accomplished on our old trucks. To me that's how I learn is hearing each and everyones opinions and ideas because we have all tried different things and came up with different results and it's good to share our experiences with eachother. I just appreciate you taking time to help me with my issue