1G Fpr spikes to 22

[96talonchick]

1g 6 bolt swap into 2g. Why is it that randomly while driving my fpr jumps to 22 or higher? Of coarse the car runs like crap and I have to push the clutch in and let the rpm drop before I can engage it again.

What can I do to fix this?

 

[totaleclipse_05]

Are you saying your fuel pressure is dropping to 22psi? It should be at 43.5psi on a 2g. What is your fuel setup?

 

[Tyeler18]

I think she's meaning AFR is spiking to 22:1?

 

[curt-s]

spikes where? what rpm and intake pressure? idle only or truly random? throttle position? openloop or closed loop? new o2 sensor? are you running zero tuning capability? does it recover or stay? is it just a blip like a series of misses? does it start right away after ignition or take a while after warming up?
the lack of background information is about as useful as an answer such as "do stuff to make it work better"

 

[96talonchick]

Yes, I'm so sorry! I meant afr, my phone dislikes a lot of the abrevations and sets it w/e it wants. So sorry for the confusing.

spikes where? Not sure what this means

what rpm and intake pressure? Rpm is
always lower, cruising speeds. Less than 3k

idle only or truly random? Has only done it while it is at cruising rpm, doesn't matter if it's just been beat on or if I granny drive it.

throttle position? This is a question for my husband, can ask when he gets home.

openloop or closed loop? Not exactly sure, again a question for my husband.

new o2 sensor? Yes, but have no rear o2 sensor.

are you running zero tuning capability? Other than basic diy tuning such as adjusting fuel pressure, no. No way to tune yet.

does it recover or stay? It will stay unless you push the clutch in and let the rpm drop. Once it's dropped, engage lurch and good to go.

is it just a blip like a series of misses? It runs horrible. Zero power if you try to push through it and it feels like a sputter.

does it start right away after ignition or
take a while after warming up? Both, it does it when it wants to. I have yet to find a link between a cause and effect.

Now I will say, I do know since I have no tune and it is a 6 bolt in a 2g with a 95 eprom ecm-this issue I posted about is not the "runs like ass issue". I have felt the occasional miscommunication from the ecm, that feels like I am running on 2 cylinders, bucks and is just down right not cool. That is a simple fix of, shut it off and restart... goes away until it does it again. This can only be fixed by a tune, which I understand.

Also, we have ran my pins to the ecm as firstly being rewired (was told we had to) the car fired and ran but just didn't seem right. It still had the issue I am posting about. Now we r running a factory 2g pin to the ecm and the car idles better, has better gas milage but I noticed today it still has the issue I am posting about and it has hesitation around 2.5k only at cruising.

 

[jim95redgsx]

This sounds very much like you're getting a PO300 "random misfire" code.

The 6-bolt engine has no provision for a crank position sensor. You have to use a 1G CAS. The 1G CAS is not compatible with the 2G ECU's misfire detection circuitry. This will show up as false misfires. The ECU will then turn off the injector on the cylinder that it thinks is misfiring the most. It does this to prevent overheating the catalytic converter with too much unburned fuel and for emissions.

The ECU will only check for misfires after a 300 second, closed loop, highway cruise. It will not check for misfires at idle or WOT. Turning the key off and then back on will reset the ECU until it completes another 300 second drive cycle.

The solution is simple with ECMLink. Just disable misfire detection. Without ECMLink, you'll have install a 10K potentiometer on the Baro wire input to the ECU. Keep in mind that this will cause the ECU to think that the car is at an extremely high altitude and adjust fuel and timing accordingly.

Do a Google search for "Magnus Motorsports 1G in a 2G". Scroll down to the troubleshooting page. This will explain how to install the 10K pot.

When the ECU detects false misfires and turns off an injector, it will cause the wideband to read extremely lean.

Jim

 

[96talonchick]

I do read random misfire when I scan the car. And this so makes sense! Sadly I can't afford the dsmlink just yet, so that's why I have been dealing with this. Thanks for the input, I will look up the other fix you mentioned.