Will 24lb Bosch injectors work w/ oem 420a?

[DSMOCTANE]

I just purchased these injectors listed below. They are Bosch/Ford Design III 24lb injectors with part #0280155715 stamped on them. Will these work as a substitute to the OEM ones on my fully rebuilt stock oem 420a engine? Says the specifications of these injectors is estimated around 25lb (255cc) @ 3bar - 43.5psi. I know in the sellers listings it says compatible with the 420a, but Im wondering if anyone here has ever used them before? Should these work? Also, what are the specifications of the stock oem injectors that come stock with the motor?

4 - 24lb BOSCH Fuel injectors Neon Eclipse 420a VW Audi 2.0 Jeep BMW Tiburon | eBay

 

[bullettdsm]

There is no advantage to installing these (unless you are planning on turbo). They have an output just slightly larger than stock. They will work but will run a little richer but you will get no power gains. The stock injectors will take you pretty much as far as you can go NA.

So basically, if you put these in you will only be wasting gas.

MB

 

[DSMOCTANE]

Thanks for the help. I already ordered these and had them delivered unfortunately. However, I have been considering eventually boosting the 420a in the near future. Its just a matter of time. Damn OEM injectors go for big bucks new and even re-manufactured, and I happened to grab these off of ebay for a decent price. You think my new motor can handle these for now as a naturally aspirated for the next few months or so? Not that this is too relevant, but I have a MSD ignition coil pack, short-ram intake, and a full header and exhaust system installed. Hopefully it wont run too rich with these for the time being if installed. If you think I should just go back to OEM then maybe I should hold off before I even think about installing these injectors. But then again, I have hopes and dreams of eventually running low boost with her, just not right away. Also, what do the stock injectors run as far as lbs and cc's go? I couldn't find a clear answer throughout other member's posts.

 

[necrotopsy]

210cc as far as i know is stock.

 

[DSMOCTANE]

So if I am running 20 to 25 cc's higher than OEM wouldn't the stock ECU be able to compensate the air-fuel ratio accordingly to these?

 

[Bud92gsx]

I sold a set of 390s to a 420a guy..I think hes got MS tho for tuning.

 

[bullettdsm]

So if I am running 20 to 25 cc's higher than OEM wouldn't the stock ECU be able to compensate the air-fuel ratio accordingly to these?

Ok, here's the lowdown;

First off, as far as the size of stock; you get a lot of different answers because.....there are a lot of different answers .I believe 210cc is the listed size. But we have come across a few different listed sizes in various reputable forms. So to see for sure what size we have, Corbin (from 2gnt) sent a set out to RC and they came back with the number of 235cc. I sent a set out to Marren Motorsports and they came up with 225cc.

So as you have seen, its kind of an "up in the air" kind of thing.

As for running slightly bigger injectors, here's the problem; the ECU is set on the understanding of stock parts. So it will make adjustments with the expectations of having stock injectors. So if the information says the car is running "such and such" rich, it will give the injectors voltage information to open up for a slightly shorter period of time based on the stock injector information. Unfortunately, if you have larder injectors in there the ECU compensation won't be enough. (I know this is a very basic description of what is happening. I hope you understand without me going into how an injector works, max flow, duty cycle etc. Basically it will squirt more fuel because the ECU can't recognize a diffferent, larger injector).

Now, with the size differential that you have, you would probably not notice the extra gas spent (except maybe in reading the plugs). But like I said before, there would be no advantage and you would just be wasting fuel.

How far can the stock injectors go? Generically, the point seems to be right around 180whpish before you start running into 80's duty cycle (that's emperical on the few NA cars that have reached that point. Also, that's with MS which allows you to adjust fuel and spark).

Another point to make on using those for turbo; if you are looking at low boost on a s16G, those should make it. But once you start going above that, you will need bigger injectors.

Hope that's not too confusing .

MB

 

[DSMOCTANE]

No, it all makes perfect logical sense and I appreciate it! Always great to hear a from a fellow CT DSM'er also! I may end up trying them out and keep an eye on the plugs time to time. The manifold was a biatch to rip off while the blocks in the car, however, if shes running too rich and throwing CEL codes then I may have to resort back to OEM. Long story short, my father and I had purchased a used 420a engine and overhauled the entire motor with a stock oem rebuild. I really wish we just bored and stroked her while it was all apart, but I will save that fun for the 4g63 days to come. I was tight on funds at the time so we had reused the injectors from the original motor. I had a malfunctioning pcv system and believed my injectors were faulty also, because I had tons of oil being sucked into the intake manifold, fouling plugs, massive oil consumption, and misfire codes galore. The leak down test had also proven successful in every cylinder and we have uniform compression of 200 psi in each cylinder. This led to initially ripping off the whole manifold and me wanting to put some new injectors in there. Luckily, I have another spare manifold that was chemically washed inside and out, so now we got a fresh start and I want to get it right this time around. I also purchased an oil catch can and hope to eliminate any oil contaminants from getting thrown into the intake. I probably should get out of the newbie forums I know, but it seems the wise men are so much more helpful here! P.S. Should the pcv valve still be attached if I am using the oil catch can now? .