I have an issue where, especially in cool weather, when the engine is not all the way warmed up, I get a terrible bog down on acceleration. The thing just starts sputtering and can barely get going. I have to basically ease really slowly into the throttle and get it gradually up to speed, then it's happy.

This is a 7747 on a 350, mostly stock but I did put cop car injectors on (don't ask me why, I'd take it back now if I could). I read that the AE is not a function of BPW (which I have adjusted), so maybe that's my problem?

I started with an ASDU bin and have adjusted my BPW down to 122. I think I should scale my AE vs. dTPS and AE vs. dMAP tables by a factor related to the flow rate. I've been assuming 55 lbs/hr for normal 5.7 injectors and 65 for cop car injectors so I'd scale by 55/65 = 0.85? Does that sound right? I tried this and didn't notice any big difference, but then I don't have a cool day to work with right now.

Anything else I should worry about with respect to bigger injectors? Thanks.

 

The early stock 5.7l injectors are 61 #/hr. Also need to adjust the proportional gains.

Although the change from 61 #/hr to 65 #/hr isn't all that much.

RBob.

 

Thanks. Yeah if it's 61 to 65, I can't believe it's causing my symptoms - but I did go from 135 to 122 on the BPW to get the BLMs even in the ballpark, so something is up with fueling. The whole story is that I bought a TBI "system" from a company and they accidentally sent me a throttle body and injectors from a 305. We couldn't get it to hardly run until I discovered that the injectors were wrong. I swapped the 305's for cop cars and started over on the bin. Could there be anything else going on, like the fuel pressure being different for a 305 setup?

 

61 / 65 = 0.94
122 / 135 = 0.90

Fairly close ratios.

Maybe try reducing the MAP & TPS AE PW tables by 8% (multiply by 0.92).

RBob.

 

Can you elaborate on the proportional gain thing? I searched in Tunerpro for "gain" and "prop" and haven't found nothing. What should I look for? Thanks.

 

These two tables:

Pick one of them and reduce the values by the same as noted above.

RBob.