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-   -   hesitation throughout and loss of punch (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/hesitation-throughout-loss-punch-908690/)

bokboked 06-14-10 06:23 PM

hesitation throughout and loss of punch
 
So i've been searching and havent really found any conclusive info that applies to my situation so please help me diagnose my problem?

So just recently out of no where i've been getting really bad hesitations while i accelerate. It makes it very hard for me to even start off in 1st.

When i accelerate it seems like i'm going on and off the accelerator but im holding it still in actuality. i have a small hesitation at 3500 which is the usual thing but it hesitates all around the rpms.

If i floor the pedal, the car accelerates but not at the normal accelerating speed and it just seems like there is a lack of power.

The car is an 86 na and all stock with just a free flowing bonez cat.

please throw out just advice and wat i should check before replacing things.

Known issues:
-slave is leaking and needs replacement.
-throw-out and pilot bearing need replacement.
-Clutch needs replacement as well.

waldog 06-14-10 07:24 PM

What kind of gas you using?

bokboked 06-14-10 07:39 PM

regular 87

SpeedOfLife 06-14-10 08:25 PM

Fuel filter? Bad TPS? Bad O2 sensor? Fouled plugs? Leaky injector(s)? Wouldn't hurt to check the compression either, just to be sure.

bokboked 06-14-10 09:05 PM

kk fuel filter was just replaced so that shouldnt be the cause, o2 sensor is fairly new as well at most one year.. TPS i'll have to check, plugs were replaced but will have to check. injectors? maybe havent touched them.

thanks for the input speed i'll check back with updates.

anyone else have any other things i can check?

FC_fan 06-14-10 09:46 PM

did you change the plug wires recently too? might be those, I have had them arcing like crazy before for some reason (maybe just stock 1986 wires,idk it was when I first got the car) and it acted like you are saying. does it feel like its misfiring kinda? definintely look in the bay at night to see if you have arcing from the wires. could a bad coil pack cause this too guys? I don't know about the pack but just my .02

barnett87rx7 06-14-10 10:03 PM

try the grounds the 3500 hesitation is a bad ground that screws up the secondary injectors

bokboked 06-17-10 02:53 AM

Will try all this and check back soon. out of the country for a bit but thanks for everyone's feedback!

calpatriot 06-17-10 01:21 PM

First thing is always *check for codes*
Make any repairs as necessary to clear codes
Check for closed loop operation at cruise
Check fuel pressure
Check for proper operation of EGR
Check for proper operation of double throttle diaphram, thermovalve, delay valve
Check TPS for max/min resistance values, dropouts, and then adjust
Check AFM for resistance values and dropouts
Check for excessive backpressure (does the problem go away if you pull the O2 sensor and leave the hole open?)
When was the last time the fuel injectors were cleaned? If it has been more than 30k miles, that could be part of the problem...
Water themo sensor
Intake air temp sensor
Altitude sensor
Boost sensor

Backprobe the connectors to the ECU and compare voltages against those pubished in the AFM, for 'ignition on/not running', and 'running, at temp' conditions.

FC3S Mitchell 06-17-10 02:49 PM

if it feels like its bogging, could possibly be belt slippage, the alternator could use some readjustment, the belt could be worn... if it occurs alot when you turn (sharp, or not) its the belt mos def

bokboked 06-19-10 01:21 AM

oooh wow great thanks everyone. not really sure on how to test everything that calpatriot said but i'll check the fsm cause i think they have all the info there. i'll check back in a month when im back in the states

the faster one 11-30-10 02:52 PM

i am having the same problem.
i own an 88 na
i have my suspicions about the EGR valve being the problem as i can hear a loud ticking that sounds like it is coming from the top of the motor, where the EGR would be.
my hesitation is mostly in the idle-3.5k rpm range, after that she seems to run smooth however with lack of power
NOTE: this happens very infrequently which is also concerning. some days it will be perfect and some days a mess... another guess for the EGR, ground short, or injector failure.
my vehicle also has hard starts in the morning cold and stumbles all over the place till she's warm.

im not sure why but my finger is pointed at the EGR. could i be right??

satch 11-30-10 03:04 PM


Originally Posted by the faster one (Post 10343627)
i am having the same problem.
i own an 88 na
i have my suspicions about the EGR valve being the problem as i can hear a loud ticking that sounds like it is coming from the top of the motor, where the EGR would be.
my hesitation is mostly in the idle-3.5k rpm range, after that she seems to run smooth however with lack of power
NOTE: this happens very infrequently which is also concerning. some days it will be perfect and some days a mess... another guess for the EGR, ground short, or injector failure.
my vehicle also has hard starts in the morning cold and stumbles all over the place till she's warm.

im not sure why but my finger is pointed at the EGR. could i be right??

The EGR is just for emissions and would not affect the drivability of the car unless it was causing a vacuum leak as far as I know. While the car is running spray some carb cleaner on it and observe for a change in the idle. No change in idle thus llikely no leak.

MNMarine1991 04-12-11 11:32 AM

I have a 91 N/A and having the same issue. I just bought it, the owner before me took the air pump off and 6P valve actuators off. Do I need them? He also told me it is Streetported and I need to run Premium, is that true? I am going to try the solutions previously posted on my car today.

the faster one 04-12-11 07:13 PM

there is a known grounding issue to the secondary fuel rail that allows the secondarys to intermittently work causing a form of hesitation and irregularity

also, you would need the airpump if you wish to utilize the auxiliary ports and the VDI. it is not necessary to have these things, but it is also dependent on how your car is setup. are the port sleeves still installed in the vehicle or are the actuators and sleeves removed? no sleeves= no power until 3800... dont think premium is required after a street port but ill let someone more knowledgeable chime in on that.

armen505 04-12-11 07:17 PM

Check your coil packs for spark. Same thing happenned to me and it turned out to be one of the leading coils. I was running on one rotor.

Oops, just realized this is an old thread...Oh well.....Check your coil packs anyway.

the faster one 04-12-11 07:22 PM

^^ +1


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