I've put a large cam into my 305 TPI, which I now know wasn't such a great idea as far as a match goes for the LTR set up. Anyway, I'm having some troubles getting the thing to run right at WOT. Part throttle and idle are doing great, but full throttle still goes sputter sputter sputter. Letting off just a tinge to 3/4 throttle it takes off like someone kicked it in the butt with a spiked cowboy boot.

Has anyone used anything similar to the Summit SUM-K1104 cam and tuned their TPI? IIRC, the specs are 224/224 @.050 280 advertised total duration, .465/.465 lift and 114 lobe separation. I'm using this with a stock 305 TPI long block, SLP runners, cold air pipe, removed A.I.R., stock manifolds and Y-pipe leading to a custom 3" catless back system.

I had three leaking injectors (also had broken fountain tips under the pintle caps) that I thought were the problem, but have since replaced those. I'm in the process of getting together the cabling and have the Moates software downloaded to scan the readouts... could someone point me at a few things to look for once I am able to look at it?

I've lowered the timing pull in the "Maximum knock retard in PE mode" tables down to just about nil to see if I was actually getting any knock timing pull to no avail... Help!

 

Also, I forgot to mention... the main changes I've made were in the "fuel PW vs. LV8" tables. Should I have looked elsewhere to make changes for the cam?

I thought about the MAF tables too, but I'm not much of a whiz when it comes to rebuilding those tables. Is there a math formula that would allow me to know what values the MAF reads? I can figure the engine's physical ablity to breath by guestimated cylinder filling %, multiplied by the bore and stroke using the new vs. old camshaft duration. Am I on the right track?

BTW, 165 ECU...

 

sounds like your out of injector or fuel pump. couyld also be that youve got to high or low of a value in the pw table.

 

Not out of fuel because it's does it as soon as I go to WOT, no matter the RPM. Taking fuel away from the high load PW value makes it lessen just a tad, adding fuel it stays about the same. The problem is, I've taken 30-40% of the PW value off of the high load values without much of a change, so it seems to me like I'm masking another problem that the ECU is seeing. Guess I'll have to wait for the ECU to talk to me...

 

When you can get some short scans of the problem then repost. Need some data.

Tim

 

Yeah, I know you would need more data to be able to actually tune it. I was just trying to get an idea from someone that may have had something similar happen with a long duration cam change in a 305 TPI and where they made the most changes. Once I get the data, I should be able to tune it myself. I just wanted to cheat a little bit and have some of the info before the scanner stuff got here...

 

if it happens as soon as you go WOT, it prolly has something to do with the PE parameters... does it bog JUST when going to WOT, or when you give it a decent amount of throttle... if it does it when you give it a decent amount of throttle, maybe it has something to do with the AE tables, most likely the delta LV8 controlled ones.

 

3/4 throttle it's fine up to redline, full throttle at any rpm and it sputters. I've been dinnking around with PE a bit... we see how it comes out after this weekend of tooling around with it...