Question: fuel injectors

[noswalyeroc]

I am considering installing 30lbs injectors in my 1989 factory L98. I know I will not get any increased performance. I just found the injectors at a great price. I know the computer will adjust flow for factory settings. Does anyone have any ideal if this would matter one way or the other.

 

[TedC]

Yes, it does matter. Is your 1989 stock or near stock? If so, I suggest you stick with stock injector flow rates. Even going from the stock 22 to 24 lbs can cause issues. If the injector flow rates are changed, then you need to reprogram the EPROM to match. Regarding performance, if you have a stock EPROM (no mods), your performance will decrease running 30 lbs. The ECM can make some minor adjustments to fuel mixtures, but not to the levels required, and not at all in power enrich mode. You can pick up a set of 22 lbs Bosch IIIs from FIC for around $180.

 

[noswalyeroc]

Yes, it does matter. Is your 1989 stock or near stock? If so, I suggest you stick with stock injector flow rates. Even going from the stock 22 to 24 lbs can cause issues. If the injector flow rates are changed, then you need to reprogram the EPROM to match. Regarding performance, if you have a stock EPROM (no mods), your performance will decrease running 30 lbs. The ECM can make some minor adjustments to fuel mixtures, but not to the levels required, and not at all in power enrich mode. You can pick up a set of 22 lbs Bosch IIIs from FIC for around $180.

Thanks information well taken. I will use stock 22lbs. Thanks again

 

[boomdriver]

Thanks information well taken. I will use stock 22lbs. Thanks again

Good choice...
you;d be seriously bummed out if you had stuck 30s in a stock engine. The ECM has a very narrow window of compensation...it cannot adjust for that much gas being shot into the engine..it would attempt to narrow the inj pulse until there was no pulse at all.

Bump up the inj size as you modify air induction and displacement. If you get a better exhaust system , do some intake mods like some mild port work, larger throttle body, improve the air flow, and alter the 'tune' with performance programming then a step up to 24-26 is justified. Just keep in mind that the ECM has a magic number that it MUST live by... 14.7:1 It makes adjustments in fuel delivery thru info from the MAF, o2, TPS and temp sensors. No matter what else is happening the ECM is trying to maintain that number.

So if you make more air available, then you can make more fuel available,. but not vice versa. Because air is easier to regulate and manage, Thats the one you can make mistakes with. Fuel requires changes in parts because the injectors have a fixed amount that they can deliver...its the duration of the inj opening that is used to regulate fuel flow to the engine.

How good was this "good price" ?? Just curious.

I am pretty sure that some Bosch-III's either recon or refurb w/warranty are still available from FIC for a little over $200... Half the C4s on the planet have those replacement injectors from FIC.