help! flat spot in low rpms

[topnotch]

hi guys.. so here goes the sernerio ive recently had my engine overhauled and sence ive gotten back the car it dosnt sound rite, when moving from a stop as i press the accelerator thers a flat spot just before 1000rpm's after 1000rpm's the car sound fine, while goin through 1000rpm's from a stop it sounds like its trying to catch itself like a clogged fuel injector or clogged trottle body but the thing is i took down the trottle body the plenium and took out the injectors to have everything cleaned put it all together again and i still have that flat spot,later after examining the whole engine bay for unconnected hoses i found one that the mechanic didnt put in, this hose led from the trottle body and connects to another double pipe which one goes to the fuel regulator,so i disconnected the battery pumped the brake a few times (not sure what that does) to reset the ecu, unfortunatly i still have the flat spot altho its not as bad as before... so ther it is am really stumped on this one i thinking of an ecu fault or problem, any ideas are soooo welcome thanks

[TI-CAVA]

below 1000RPM i don't think the engine can keep up... i mean IDLE is 900-1000RPM... AC on idle is 1200RPM....

[topnotch]

well rite now it idle's around 1000 rpm's in park but when i put it in drive it drops below 1000rpm lets say around 800rpm dont know why it drops that low but when i accelerate it soundslike it misses a beat in rpm and stutters tikk it passes 1000rpm.

[topnotch]

its even worst with the ac on you can hear the engine stutter at intervals even in park

[topnotch]

ok update guys... i did some reaserch on possible reasons for the flat spot and irratic idling at low rpm, and found out that the TROTTLE POSITION SENSOR can be one of the causes, so i went out to check it out and set it and now its idiling at a perfect 1000rpm in park and when put in drive it drops to 900rpm but i have to test drive it tomor to see how it responds altho am still getting that hiccup in the idiling at periods sound like possible missfire? if so what causes that ? any response and help is greatly appreciated.

[gold94corolla]

Did they reset the ECU? If so, it takes a while for it to relearn it's settings, and until it does, it will be hesitant like you say. ?

[topnotch]

Originally Posted by gold94corolla

Did they reset the ECU? If so, it takes a while for it to relearn it's settings, and until it does, it will be hesitant like you say. ?

hmmm ok i'll gave it sometime to relearn its settings then but as for the slight jerking when the engine sounds like its miss firing while in drive is also contribute to the ecu relearning or is it a distributor or spark plug issue?

[gold94corolla]

Sometimes these problems just iron themselves out after a while....

[topnotch]

yea i guess so... it has me drinking gas like a camel tho lol but am just goin to look over the distributor and spark plugs and take it for a country drive later on today, but at least sence i reset the TPS she idle alot better

[gold94corolla]

Drinking gas like a camel..... so you are getting 100 MPG?? LOL.

[topnotch]

lol