injectors plugged

[dart347fox]

Hey guys , got a little problim I could use some help with , Just finished building my intake and fuel system and I cant seem to get this thing to run right . The problim is that when I start the car it wont seem to Idle properly and heasitates when i open the throttle it sumbles and has a tendancy to die . I have a feeling that this may be a result of my earls filter not filtering fine enough and pluging my injectors (dang ) not sure if this is the problim or not but it is all I have come up with so far , any suggestions comments or criticisms are welcome and I thank you all in advance .

P.S I searched the forums for info on a similar problim but im not sure if i did it right

Here is some info on my combo

80mm cc&l mass air
42lb injectors
225 lph fuel pump
earls screen type fuel filter
70mm throttlel body
dart 195cc pro 1 as cast heads
Victor Jr. intake
timing set at 10 degrees ( yes I Know how to set it)
vortech s-trim
347 stroker
aprox 8.9:1 compression ratio

 

[Daggar]

I see no mention of a custom chip or tune yet you're attemting to run 42 lb injectors with nothing more than a recalibrated MAF sensor. The EEC has no clue what it should be doing with 42s or that they are even there.

 

[ninety1gt]

did u change out the o rings on the injectors, could be leaking vacumm from there, mine had the same problem when i switched injectors

 

[dart347fox]

yeah , no tune yet as I am having trouble deciding whether to use a programer(tweecer r/t or afm pms) or if I should invest in accel dfi , or holly comander system . Corect me if im wrong but I was under the impression that there were some people out there running #42 without a custom tune? Would it realy cause it to run that badly? I can understand the idle problims but it seems like the motor is only firing on 6 cylenders sometimes and as I increase the fuel pressure it seems to get better ( seems best at 70-80 psi) if it were strictly computer related I would expect it to run beter at a lower pressure( 30-40 psi ) . again any input or criticism is more than welcome.

 

[Daggar]

I've heard folks say that they've seen 42s run well with a calibrated meter and no tune but I've never seen one. Until I do, I'll consider that an internet myth. Here's why:

The EEC (regarless of the MAF calibration) is set for 19 lb injectors. Fuel tables, fuel ramps, injector break points, injector minimum and maximums, along with spark tables that coincide with the amount of fuel the EEC "thinks" it's sending, will all be wrong. The EEc can do a reasonable job of compensating for 24s over a period of time, but once you start getting into injectors over 30lb then you're outside of the EEC's ability to apply adaptive control. 20% out of the norm is the rule of thumb for adaptive control to be able to do it's job (That a 22lb injector at stock fuel pressure if you're keeping track). The saving grace for injectors that are smaller than 42 are those breakpoints and mins and maxes that I mentioned before. They're not nearly as far away from those of the 19s as they are for the 42s (obviously). So even if the EEC knew what the minimum pulse width was for a 42 (which is allot lower electrically than it is for a 19) it would still be all haywire when you stepped ont eh gas (a 42 will dump allot more gas than a 19 will in considerably less time). Does that help?

BTW: I saw a PMS for sale for $600 someplace. I'll PM you the link.

 

[dart347fox]

I always thought the #42 injectors and stock computer combo sounded a bit to good to be true . just got back from an inspection of my home made fuel rails and injector tips and they dont seem to be dirty so unless somone can think of a better idea im going to take the advice of daggar and get my poop in a group as far as this computer thing is concerned and see where that gets me.


btw thanks for the pm daggar.

 

[Daggar]

NP... check out the forums for the Anderson PMS and TwEECer to get a better idea of what each can do for you. Since you aren't going to need to load MAF tansfer function (your MAF is already cal'd for 42s) and the PMS is tons easier to learn and operate, I figured it might be a good thing for you to have if you're not interested in the custom chip route.

 

[shttygtstang]

first off dump codes... confirm timing(y only 10 degrees??) then hunt down ecu gremlins.Ive heard of 42lbers runing in cars but it runs like crap. very rich but still ran good enough to go do what had to be done..
how many lbs of boost is that s trim set up for ne thing after 9 lbs you need a bov/by pass valve for it to idle right . also i would unplug the iac and try to set the idle manualy. ive also heard people having to drill a hole or bigger hole in there butterflyh of there tb..good luck

 

[dart347fox]

10 degrees initial seems to me like a good starting point with the blower.
I of course have a bypass valve and have done all of the diagnosing I could think of as far as the idle goes. Should have the new programmer soon and I will keep you posted.