Alright!, new car and first troubleshooting!!!!

[oricale]

So I have the car and I want to get some opinions on a issue.

Key off Runs fine no issues....

Key on runs fine until I hammer it and she hesitates (all gears)

PO said he used to have a burned chip in it and now it's stock. Has a B&B exhaust and I think that's it.

The hesitation is not extreme where the car is falling apart its just stuttering from 3800 up.

:handshak:

[GOLDCYLON]

So I have the car and I want to get some opinions on a issue.

Key off Runs fine no issues....

Key on runs fine until I hammer it and she hesitates (all gears)

PO said he used to have a burned chip in it and now it's stock. Has a B&B exhaust and I think that's it.

The hesitation is not extreme where the car is falling apart its just stuttering from 3800 up.

:handshak:

Injectors would be my WAG, I would do a fuel pressure check as well maybe as simple as a fuel filter

[Coupe89]

Are you getting a SES light when passed the 3K RPM mark?
If so, you may have a a vacuum leek in the secondary system.

[scottfab]

Good job of listing the symptoms.
Just based on those I'd say you have one of the two secondary actuators sticking a bit. Common if you don't exercise at WOT much.
One way to isolate is to do many WOTs in a row. If the stumble does not repeat every time after that then that's it.

On the other hand if you go WOT and hold it for >10sec and you feel the torque flatten out then it's your secondary vacuum pump or a leak. That is you begin the WOT and all is strong up past 5000rmp then after a bit you feel the power drop off.

[Schrade]

Check H History DTC...

Air filter? K&N? Too much oil???

Did your wife see exhaust color with hammer down?

Put a compression guage on it and check the squeeze? (static compression too / leakdown time)

[ZZZZZR1]

Injectors would be my WAG, I would do a fuel pressure check as well maybe as simple as a fuel filter

I agree. Typical 20yr old issues

Injectors. Coil packs. Spark plug wires. Spark plugs. Fuel pumps

:cheers:

David

[oricale]

Thank you for the responses!!.

The PO said he changed all the coils,wires and plugs. I actually have the stock ones he pulled out. HOWEVER.. I did not get secondary injectors!.

No lights light up, it just feels as though it push bad gas .


also: Opinions please

I am debating replacing the stereo in the car...With the history and provenance that this car goes with should I stay stock or install???

finally:

I asked a few other poeple....My throttle body has a STAMP OF AN RP # AND A SERIAL # on it.

Any ideas??

[GOLDCYLON]

Thank you for the responses!!.

The PO said he changed all the coils,wires and plugs. I actually have the stock ones he pulled out. HOWEVER.. I did not get secondary injectors!.

No lights light up, it just feels as though it push bad gas .


also: Opinions please

I am debating replacing the stereo in the car...With the history and provenance that this car goes with should I stay stock or install???

finally:

I asked a few other poeple....My throttle body has a STAMP OF AN RP # AND A SERIAL # on it.

Any ideas??


Yep the secondary injectors.... The fact that you mentioned no SES light No codes, fine at startup however struggles all the way through the power band with key on is a dead give away.

I suggest replacing the Radio unless your considering NCRS.

Take a pic of that stamp and general location

[SteelBlueZR1]

Don't forget to check the MAP hose and replace it with new oem unit from Jerry's if it is not original hard line that won't collapse at high rpm... Also check secondary operation with plenum on using the procedure here: http://www.zr1specialist.com/HAT%20Web/articles/Verifying%20Secondary%20Actuator%20Operation.pdf
Finally, don't discount the secondary selonoid switch failing as the cause. My car had similar symptoms and a new selonoid solved the issue... Good luck with your new Z!

[Blue Flame Restorations]

Sounds like since you have an early car that "may" have been used for evaluation PEP, I'd probably leave the secondaries intact and leave the car stock, especially since you already have a nice Z to flog.

Eric can probably help you on the stamped codes on your TB.

Again, congrats on the nice find! :cheers:

[oricale]

Brett,

Yes it was a PEP car just not sure what for. It had 14,000 miles before it was titled!.

I will probably refresh the top end with paint and whatever as well as new seals injectors ect. but stock is the path for this car (maybe wheels)

who is this eric you speak of?..I need info!:cheers:

thanks man!:handshak:

Dempsey

[Blue Flame Restorations]

Brett,

Yes it was a PEP car just not sure what for. It had 14,000 miles before it was titled!.

I will probably refresh the top end with paint and whatever as well as new seals injectors ect. but stock is the path for this car (maybe wheels)

who is this eric you speak of?..I need info!:cheers:

thanks man!:handshak:

Dempsey

Check the Prototype Section Send him a PM

Eric Jackson
Forum Name 1989ZR1#74

[GOLDCYLON]

Sounds like a 89 to 90 prototype set up. My Phase II plenum and TB has a RP number stamped under the TB