Stutter/Hesitation Problem

[VaderDroveGNs]

I have an 84 GN that has a hesitation/stutter when taking off if you press the gas pedal down too quickly. The car was like this when I first got it, but it wasn’t very noticeable. The car was originally bone stock, but after some upgrades (Walbro 340 fuel pump and hot wire kit, billet adjustable fuel pressure regulator, 160 thermostat, 42.5# injectors, a heated O2 sensor and a new chip) the problem got much worse. It was fixed a little by turning the TPS all the way up, but this causes the check engine light to come on. Currently, the car is very drivable but it will pretty much stutter and stall out if you give it too much gas from a stop.

So far, I have tried cleaning the MAF sensor thinking that it might have been dirty but this didn’t work. Any suggestions on what may be giving me grief/needs replacing would be greatly appreciated. Thanks.

 

[RegalT-type85]

any scantool readings? let the check engine light on and get the code being thrown. I'm sure it will come up as bad TPS but might give you something else.

Sounds like a Vac leak,bad TPS or IAC(going out) Listen to the motor at idle for any hissing. Not to sound like a Ahole here, don't take it wrong. This is what happens when you throw parts/money at the problem hoping it gets better. I only say this for advise, many of use have done, do this and it cost alot doing so.


hope it something simple brother.

 

[turbobooster]

This is only from personal past experience my car had that stutter hesitating problem but never stalled out I replaced a bad coilpack/ module and the car ran way smoother eliminating those issues try a known good coilpack/module to see if that helps what do the towers on the coil pack ohm out to?

 

[VaderDroveGNs]

Thanks for the suggestions y'all. I'll look into both of them next time I get a chance to tinker around with the car. If it isn't the TPS or coil pack do you think the MAF sensor could be failing?

 

[Jerryl]

Thanks for the suggestions y'all. I'll look into both of them next time I get a chance to tinker around with the car. If it isn't the TPS or coil pack do you think the MAF sensor could be failing?

Rough estimates ;
Ignition Module and Coil pack = $40 (Used) - $400 (87 Conversion + pigtail Adapter, mounting plate etc)
TPS = $70
MAF = $60 (Used) - $300 (Known good LT1 + Translator)
Having data with PowerLogger for $250 = Priceless

 

[edmonds27]

I know this is probably gonna sound way off but... Does it still have the stock cam? If not read the thread Tuning Timing with Casper's Cap (still on the first page of the HA section last time I looked) and read John's comments toward the bottom. Just a thought...

 

[85typet]

i have an 84 gn that has a hesitation/stutter when taking off if you press the gas pedal down too quickly. The car was like this when i first got it, but it wasn’t very noticeable. The car was originally bone stock, but after some upgrades (walbro 340 fuel pump and hot wire kit, billet adjustable fuel pressure regulator, 160 thermostat, 42.5# injectors, a heated o2 sensor and a new chip) the problem got much worse. It was fixed a little by turning the tps all the way up, but this causes the check engine light to come on. Currently, the car is very drivable but it will pretty much stutter and stall out if you give it too much gas from a stop.

So far, i have tried cleaning the maf sensor thinking that it might have been dirty but this didn’t work. Any suggestions on what may be giving me grief/needs replacing would be greatly appreciated. Thanks.

my 85 hot air does the same thing.!!!!! You can get on the gas and it dies out until it catches itself and if you kind of gas it(moving pedal back and fourth) until the rpm's get up it will be fine until you make a stop and if you try it regulary it will pop back up through the intake..... I done the same thing to my tps thinking it would help and it kept setting codes ... Borrowed my friends tech 2 scanner(snap on) and it said tps toooooo high and maf was reading wrong (circuitry problem)....... Set my tps to .40 on the dot and it seemed to run better my best bet is that the maf is shot .

 

[turbo6x2]

A bad tps will cause this.