Running rich and Surging.

Technical Topics specific to the Hatchback body - NOT where you post pics/build specs of your car.
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Running rich and Surging.

By Driv-it-hard
- Mon Nov 05, 2018 12:53 pm #6908820 Good day everyone. It has been a good minute since I have been on here. Life has been on the move.

Need to ask for your help.
Driving home the other day car just shut off.
Pull over and tried to start it but it wouldn't start.
Got it home on the tow , started to examine what is wrong. 95 hatch with a 96 GSR obd1 with a chipped p72 , 95 SI wire harness is the power plant.

I have checked for codes and got a Bad IACV , replaced. Replaced TPS , replaced Map sensor , changed coolant and bled thes system. I run NO thermostat. Checked the plugs , the are wet from fuel. Running rich. I replaced all injectors. Fuel pressure reg is AEM aftermarket. I have a gauge on it . 40 - 45 pounds on the dial.
I have a stock p72 that I swapped in to check and it does the same but giving a code of O2 sensor. No worries on that.
The car will start , but surging idle and running rich. I am lost at the moment. I have checked for any vacuum leaks , none that I can see.
:?
I can take a vid of the car tonight to show we're i am.
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Re: Running rich and Surging.

By EconoBox
- Mon Nov 05, 2018 5:27 pm #6908822 If you are still running the OEM throttle body there is usually a part on the bottom of it typically called a fast idle valve I would start the car with your intake tube off. Looking in the throttle itself you will see a hole to the back (facing firewall) and a hole facing down. If you take your finger and cover the lower hole and the surging stops the fast idle valve is bad. If you cover the back hole and it stops the IACV is bad.

The easiest cheapest thing to do is use a piece of gasket material from the auto parts store or a piece of a soda can and sandwhich it between the fast idle valve and throttle. Remove the coolant line and block them off.

Found this on google for reference to what I'm talking about.
Image
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Re: Running rich and Surging.

By Driv-it-hard
- Mon Nov 05, 2018 9:28 pm #6908831
EconoBox wrote:If you are still running the OEM throttle body there is usually a part on the bottom of it typically called a fast idle valve I would start the car with your intake tube off. Looking in the throttle itself you will see a hole to the back (facing firewall) and a hole facing down. If you take your finger and cover the lower hole and the surging stops the fast idle valve is bad. If you cover the back hole and it stops the IACV is bad.

The easiest cheapest thing to do is use a piece of gasket material from the auto parts store or a piece of a soda can and sandwhich it between the fast idle valve and throttle. Remove the coolant line and block them off.

Found this on google for reference to what I'm talking about.
Image



Econo, Thank you for the reply. My GSR does not have the fast idle on the TB. But I do have to check on the TPS. I did not set the adjust it with my multi meter. I will try this tonight and get back to you all.
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Re: Running rich and Surging.

By Driv-it-hard
- Tue Nov 06, 2018 1:24 pm #6908833 Good morning everyone.
Soooo. Last night I adjusted the TPS and tried everything again. That didn't help. But I think my problem is electrical. Sorry for not taking a vid. Got home real late and tried this one thing.
My guess on the electrical is on assumption of an issue that I worked on a different car. Rpm gauge jumping around and not swiping smooth across the gauge. I'll keep you all up to date on it.
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Re: Running rich and Surging.

By EconoBox
- Tue Nov 06, 2018 8:19 pm #6908834 Good luck!

First thing to check is definitely that TPS calibration with a volt meter. And make sure the thermostat housing ground is good. Those two things can cause all sorts of weird issues.
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