what I am working on is a 89 k1500 chevy with an LO5 and a 5spd. The motor wqas in great shap so I went ahead and swapped the heads for a set of 083 TPI heads along with installing some shorty headers and flipping the aircleaner lid. I adjusted the valves by the GM book and reset the timing 2 degrees with the conector unhooked. Man this thing will haul now and it sounds so much better through the exhaust. But now they motor is having a flat spot of idle till about 2000 RPM. It isnt bad but at 2 grand the motor comes to life literally like a holley 4 barrel. What gives?? With the throttle blades opened up a little more the flat spot isnt as bad but to me it feels like it is a little lean with to much timing. What do ya'll think? I was thinking about trying to adjust the TPS to richen the mixture a little bit off idle and taking out a little timing. Do you guys think this will help? I think that the computer is trying to add timing to let the stock heads work when the newer ones are more efficient and dont need the timing. Just my thought. I cant get into prom burning yet because I cant afford a laptop yet but it will be soon. Any help ya'll have would be appreciated. thanks guys

 

yes i would think it is probably a tunning issue, have you adjusted the fuel pressure? if not, that is where i would start. there is a tech article on the that shows you how to make your FPR, adjustable. of course without dataloggin, nailing the FP will take some time to get right, it would be really helpfull to get some data on what it is really doing. and what the computer is seeing.

 

Ya know I was thinking about the fuel preasure route. I have seen the article in the tech section on the fuel preasure regulator and followed it for the most part. Is there a chance of messing anything up? I dont think that there was. My biggest problem is that I am getting ready to drive cross country and really dont need the thing to be broke. However I am a compatent mechanic, I just need to take the thing apart to follow the directions. As of now the motor still has the stock injectors. Hey the things flow perfect as it is why change them. I will take a look at it this weekend and see what I can do. I appreciate the help. O yea as far as the debate about the truck motors being roller blocks, mine is, and yes she is the original block. Once I can afford the computer and burner that LT1 cam is getting slid in. Once again Thanks guys.