He is going to bring it over next week I just want some opinions b4 we start lookin into it. It sounds like a timing problem to me here are the symptoms. When it idles it has a pop...not a miss....then when you go to nail the throttle it falls on its face and the rpms go down while floored.....it doesnt backfire when you do this......then while your driving if your going 40 or under if u hit it a little it will act funny and 65 and above if u hit the throttle it falls on its face again. He has checked the map sensor, fuel pressure, ign module, wires/plugs/cap n rotor. He says the timing is fine too but who knows. What else could be causing it to run like this. A shop that looked at it b4 said it hardly had any vacume I guess we will have to look for some leaks also. No cel currently but it did throw these codes b4 at once. 34= map sensor, 44= lean, 45= rich.

 

Don't forget that ignition timing is only half the equation. Valve timing can also affect performance, induce popping, and affect vacuum.

 

Yeh im thinkin more of its prob a gasket cause he has a 100 shot hooked up to it and it just started doing this recently.

 

thanks john.....yea this is my car......the shop said that it didnt have a adj, TPS? and that the throttle plates were a little open {ie nothing to do with this} but before it was running perfect......the timing is at 10 deg advance....and at idel it isnt a constint pop just here and there....and its LOUD {IE have the cats cut off} look sliek out of 1,3,5,7 he said it was a "rich pop"......

 

also...sometimes it will run a little better when cold.....but when warmed up or driving for 45+ min it will run even worse....and will die...wait 5 min and it will start up....

 

bump

 

can anyone help?

 

Are there any current error codes (other than the previous 34/44/45)? Since there had been backfire, it is remotely possible that the MAP was damaged. Can you get a MAP output voltage reading at idle? Is the oxygen sensor active ? You should be able to meter the O² voltage and see if it is crossing the bias point.

 

i replaced the MAP before

 

well i got a data logger on it here is the prob that i see....

TPS volts 1.04
TPS volts WOT .12!!!!!!!!!!!!!!!!!!
TPS% .01 at WOT!!!!!!!!!!!!!



think thats the prob?

 

I hope replacin the tps fixes it we will have to check the voltage at the tps too. I heard of people replacing the tps b4 and still havin the same prob could even be your ecm.

 

Few pics of the tear down what we found was the intake and runner bolts on the pass side were extremely loose. Also the rotor on the dizzy was a good 1/8" away from the contact points on the inside of the cap.

 

We got it back together and its running good now.