HELP!!! engine hesitates at WOT

[boosted k20]

hey whats up. My friends 88 RX-7 has given him alot of problems. this is the scenerio:
when he steps on the gas all the way (WOT) the car will go up to 4K RPM then it will hit a wall. it wont go past 4000 rpms. it's like he has a rev limiter at 4K. But if her were to slowly take the rpms up (Not flooring the car) he would be able to get past the 4000 rpms with no problem.
whats the problem with his car? could it be a bad TPS sensor? thats what we think it is

[MBTN]

The dreaded 3800RPM hesitation. Bad engine grounds and/or stuck 5/6 port actuators.

[J-Rat]

If it hits a wall. Then one (or both) of his secondary injectors are not firing. Reason that he can gradually accelerate past 3800 is the fact that the pressure sensor is not sending a signal to the ECU to fire the secondary injection system (low engine load).

Is it a TII or an N/A?

[boosted k20]

it's the NON turbo II and it has two injectors. how would we go about fixing the injector problem. now which pressure sensor is that? the MAP sensor? could it be a bad MAP? or should we put in some new injectors?

we replaced the ECU, Mass air flow sensor, several TPS sensors, fuel filter and put in a new ported throttle body, but the problem hasnt gone away.

any help will be appreciated. and how do we check the actuators?

[J-Rat]

Originally Posted by boosted k20

it's the NON turbo II and it has two injectors. how would we go about fixing the injector problem. now which pressure sensor is that? the MAP sensor? could it be a bad MAP? or should we put in some new injectors?

LOL!!! Umm it has 4 injectors man. You cant see the other 2 because they are under the UIM. You need to check the connectors on the 2 injectors that you CAN see. Another thing. Unplug the pressure sensor (its on the passenger fender side in the engine bay). Report back!

[JTYnBJD4Ever]

My car is doing the same thing, but then once i slowly went up in the revs, my entire car wont start... can you give me a direction to go and what I should do. Thanks guys

[boosted k20]

lol. my bad. i didnt know it had 4 injectors.... i only see two of them so thats why i said that. im not too good with knowledge on these rotary's =/
oki, so this is what we should do:

-unplug the MAP sensor. do we unplug it and run the car w/o the map sensor???? will the car run if we do this man?

-check the 2 injectors that we do SEE on the intake manifold in order to see if they are connected properly. To check the other two injectors, we're going to have the remove the UIM. the UIM is the intake manifold right... just check n.

his problem is probably fuel related because his A/F ratio gauge never reads rich when he floors it. it's always lean or sometimes get to the stoich position.

oki we will try it tomorrow and i'll tell you how it goes...


p.s. you guys dont thinks it's a bad TPS sensor right? cuz thats what my friend thinks it is.

[ShortyDTP]

I use to have the same problem , It just hit a wall at WOT at 4k . The problem was #1 secondary injector. now fixed , a week went by ,now it Hesitates at WOT at diferent Rpms . Do you guys think the remplaced injector is messing up again or it might be another one of the other 3??


P.S sorry for stealling Tread , I din't want to make another tread about a similar problem.