just put my formula back together again heres the problem and what i've done so far: new plugs, wires, cap, rotor, just ported the heads, descreened the maf turned it round the right way, had to change the throttle body elbow as the stock one pretty much fell apart, erson 1.6 rollers, bbk headers and y-pipe. the issue is after driving for 10 to 15 mins car will not pull 6th anything slower then 70 any slower it just shakes and rattles everything in the car, also does it in any gear below 2300 rpm over half throttle (tach needle jumps wildly just before it starts to stumble), car surges at idle, the tach needle will jump first and then the car will rev from idle to 1500 rpm again and again and again, also noticed the other day it started coughing and surging at like 5000 rpm under wot forcing me to shift, thought i had it traced to the egr valve, i changed it, then the egr solenoid, then the throttle position sensor, have checked fuel pressure at idle and it is 42ish lbs, revved to 3500 fuel pressure is bout 39 lbs, with the vacuum line disconnected to the regulator it jumps to 47psi, the car runs fine for the first ten-fifteen mins, only does it HOT, when i let it warm up in the morning for work i still have to drive it for ten min before it starts, i had a slight antifreeze leak at the water pump on the upper radiator hose on the pass. side (was running straight across the plug in the cap), i tried the other day after it started this routine on the way home from work to unplug the maf sensor just to see if it was only an closed loop problem and it still did it, im just at a loss, i think i might have missed a ground putting it back together, as the dash lights dim for a split second when the tach needle jumps at idle, but im not sure as i recall there where three that went to the motor and one to the frame out of the main harness. just need advice.

 

Did you plug the o2s back in? Maybe you left a hammer inside the valve cover

 

could be the ECT. do you have a data logger?

 

not to be a smartass, but use some spaces man!

 

ect?? no data logger yet, o2 are plugged in but the passenger side wire was really tight.

 

ECT is engine coolant temp sensor, the one for the PCM, not the gauge

 

just curious as to how the ect would have an effect on the tach needle jumping at idle and almost cutting out when you go past half on throttle when under 2500 rpm??

 

some of the guys on fastlouis.com think its a tuning issue but I don't think this is the case......nothing i come up with explains the tach needle jumping and the surging at the same time?!?! im lost!!!!