Lots of threads on this but is there one that is particularly succinct?

My 305 TPI has developed the frequent missing now and has always struggled with the idle up issue and I've done a lot of work on it (replaced just about everything, pretty sure no leaks) but only cleaned the injectors (Echlin and gumout).

I think my next step is to take a good look at the entire fuel system.

I am thinking of yanking the injectors and sending them in but would like to avoid unnecessary cost at this point. 117,000 miles on the original injectors.

 

Took my 86 to Pep Boys a few years ago and had my injectors cleaned .IIRC it cost about $100.
https://www.pepboys.com/service/prev...ices_text-link
I have 125,000 miles on original injectors.

 

I used the Napa Echlin stuff that is injected into the fuel rail and the car runs on it until it is used up then the engine dies and it sits for 30 mins.

I may have a dying injector.

I may also have fouled a plug though. Don't wanna go looking. Not so easy. I just put in Iridiums a thousand miles ago. But the old number two plug was really fouled. Maybe I should do valve seals too.

 

Just get Southbay 19's and be done with it. Not worth the time to mess with factory injectors at this stage of the game.

GD

 

Thanks. That's a good deal. I read the Bosch D3's are better and from Southbay, fit right up.

 

Yes they fit perfect. Generally they run that way too. Some folks have had to do a little tuning but it's usually all the other mods they don't think about that add up to needing tuning - even things like a mini starter that cranks faster can benefit from tuning.

They have a much more refined spray pattern and generally people comment that they run and idle smoother. I am continually amazed at how "modern" my 86 305 with 160k on it runs with D3's. The engine acceleration is like greased glass. Frankly I'm blown away at how all the bits and bobs for the TPI in my car survived in the woods for 11 years. Except the injectors.... and the fuel pump.... and the ECM. But the rest is great!

GD

 

If the injs are the originals, you can OHM check them yourself. I'd bet they are bad or are going bad, the stock rochester injs are/were very problematic for shorting out.

 

Thanks all. I am going to move on the D3's.

 

I'd definitely wanna make sure you have good fuel pressure too. If you have good pressure, but still have a hard start, you can probably eliminate a lot of other potential fuel/line/pump issues.

That being said, I had issues with my original injectors that caused starting issues.

 

And not wanting to be a let down, the in-tank fuel strainer could be dirty.

 

I don't think that would cause missing. Maybe starvation at higher load. I ohmed my injectos 15.2 - 15.4, but I suspect clogging.

 

You have to ohm them hot as well as cold. They typically will drop in resistance when heated.

GD

 

I did them hot.

 

Just ordered my D3's from South Bay. Good price but man my budget is blowing out. NO end in sight. Having my Spohn SFCs put in now on the convertible. $300-$400 to do it right.