no change in throttle power

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mustang67n

Senior Member
ok.. just got my SOHC ZC in my 89 DX and i did the MPFI swap before..

but i have an odd question.
when i get on the throttle, there is NO change in performane when comparing anything past 1/4 throttle other than noise from the engine.
the further i push the gas, the engine kinda humms..
its the same whether i push on the pedal, or on the linkage on the TB.

sound familiar to anyone?
im thinking maybe my throttle position sensor is still wired backwards from the MPFI swap?

im not throwing any codes.. and im running a PM6 ECU

any ideas?
 
have some one step on the gas pedal, you look at the TB and see if its opening all the way.
if it is, then its okay its just slow.

what kind of tranny is on it ?
 
P.S. Do the gas pedal/trottle body thing with the motor off. (I know this seems obvious, but some things just need to be said.)


How fast are you going when you press the gas pedal from 1/4 to full throttle? If you are sailing along at 100mph its going to get louder but won't pin you to the seat or anything.

same if you are going 30mph in 5th gear.. The motor will get louder but won't take off like a rocket, it'll take a while.
 
yeah.. the TB is opening all the way.
lol. its just as fast as its ever been.. i just thought it was wierd that there was no difference between 1/4 adn full throttle..
btw, this is at ANY time in any gear.

oh.. and its a dx 5 speed.. w/e comes standard in the '89 dx *shrug*

hmm.. maybe its time for a lil spray.. just for shits. lol
 
haha, ya go with the spray just because its america and you can...plus a button with NOS on it would be sweet. If I had money, I'd be on the bottle too!
 
I'd buy an Si tranny instead.

Gearing is probably whats making it feel sluggish...
 
ive had a similar problem before...does it feel smoother at part throttle than it does at WOT?

It was my coil causing the problem.
 
yeah.. an SI tranny is on my list too.. probably get that before anything else.

yes, its MUCH smoother at part throttle
 
i had the problem you are describing too...couple weeks later, the fuel pump went out. i replaced the fuel pump, that wasnt actually what went wrong, the main relay blew. so after replacing both, the problem went away.

im just noticing how many problems my prelude has had...i need to dump this bitch.
 
allriight.. so i was checking with the other problem i had (the backfire through the IM) and i think both problems were one in the same.. i advanced my timing a bit (using the dizzy) and BOTH problems are practically GONE!

there are no more 'pops' from the IM and i actually HAVE power with the throttle pressed all the way! i actually have the dizzy adjusted as far in advance as it can be.. but its working great so i'll let it be for now lol.

leaving my house, i smoked the tires lol. i didnt even have to drop the clutch like i used to have to.. i just put the pedal to the floor and the tires broke! of course.. taht could be because my tires are near bald.. (getting new ones on saturday) lol

anyways.. YAY :)
 
mustang67n said:
allriight.. so i was checking with the other problem i had (the backfire through the IM) and i think both problems were one in the same.. i advanced my timing a bit (using the dizzy) and BOTH problems are practically GONE!

there are no more 'pops' from the IM and i actually HAVE power with the throttle pressed all the way! i actually have the dizzy adjusted as far in advance as it can be.. but its working great so i'll let it be for now lol.

leaving my house, i smoked the tires lol. i didnt even have to drop the clutch like i used to have to.. i just put the pedal to the floor and the tires broke! of course.. taht could be because my tires are near bald.. (getting new ones on saturday) lol

anyways.. YAY :)
Click to expand...
sounds to me like the camshaft timing is off - you shouldn't have to advance the distributor as far as it will go to get it to run - distributor should be right in the center of the slots, if the camshaft is correct
 
yeah, thats why i want to go at it with a timing light when i can..

i know i got the timing belt on there correct ( had to do it about 3 times lol) but its probably still off by a few teeths
 
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