2G 1998 Eclipse GSX 4g63t won’t run right at idle

[tony the man]

Hello, everyone I’m new here. I’m getting into the space of these cars but I know a good amount about cars in general but this Eclipse has pushed me over the edge.

For the last 4 days I haven’t been able to figure out what’s wrong with it. The issue I’m facing is the car won’t idle right at all. If you go to start it, it barely starts and sometimes won’t start at all. You need to give it gas to start and when it starts it won’t idle it keeps jumping up and down and will stall out. Eventually when it warms up a little bit it will idle okay at like 1,300rpm and it will idle from 1250-1400rpm but if you give it gas it will start jumping up and down again until eventually idling “okay” again. If you drive it, it seems to drive fine boost and everything else is good.

I also checked all the vacuum lines and for boost leaks. I did the FIAV bypass but that didn't fix it. I changed the TPS sensor and again with nothing changing. But something I did notice is I unplugged the tub that goes to the fuel rail and it seems like there was no pressure. When I took it off, gas just started running no squirting or anything, and I had just ran the car 5 minutes prior to doing this.

I ended up getting a fuel filter, fixed nothing (runs full e85, so assumed it was clogged because the car sat for 10 years before me getting it). I then changed the fuel regulator I got from a part out on facebook, and seemed to have done nothing.

I am lost. I have been researching for many hours and many hours trying to get to the bottom of this, if anyone can help that would be greatly appreciated.

 

[steve]

Welcome Tony,
Please fill out a profile for your car to let everyone know about it. That helps cut down on the random guessing and hopefully promotes educated guessing.

Since you say the car is running E85 how is it tuned for it? Do you have an SAFC or DSMLink?
What sort of injectors are you running and have you cleaned them?

There are several things that could cause the fuel pressure to bleed down quickly, the FPR is one and a leaking injector another.

Idle surging is common, blocking/bypassing the FIAV is the last step to solving it. Something is causing too much air to get past the throttle butterfly. Could be a leak, misadjusted BISS, Bad ISC/IAC, Looped vacuum lines, throttle cable too tight, bad PCV, leaking EGR valve, bad brake booster check valve, etc. Once you pressurized the intake for the boost leak test how long did the pressure hold after you stopped putting air in?

There are lots more questions to be answered but lets get more info on what you've done and what you're working with.

 

[pauleyman]

Hello, everyone I’m new here. I’m getting into the space of these cars but I know a good amount about cars in general but this Eclipse has pushed me over the edge.

For the last 4 days I haven’t been able to figure out what’s wrong with it. The issue I’m facing is the car won’t idle right at all. If you go to start it, it barely starts and sometimes won’t start at all. You need to give it gas to start and when it starts it won’t idle it keeps jumping up and down and will stall out. Eventually when it warms up a little bit it will idle okay at like 1,300rpm and it will idle from 1250-1400rpm but if you give it gas it will start jumping up and down again until eventually idling “okay” again. If you drive it, it seems to drive fine boost and everything else is good.

I also checked all the vacuum lines and for boost leaks. I did the FIAV bypass but that didn't fix it. I changed the TPS sensor and again with nothing changing. But something I did notice is I unplugged the tub that goes to the fuel rail and it seems like there was no pressure.

are you talking the fuel line or the small vacuum line?

When I took it off, gas just started running no squirting or anything, and I had just ran the car 5 minutes prior to doing this.

I ended up getting a fuel filter, fixed nothing (runs full e85, so assumed it was clogged because the car sat for 10 years before me getting it). I then changed the fuel regulator I got from a part out on facebook, and seemed to have done nothing.

I am lost. I have been researching for many hours and many hours trying to get to the bottom of this, if anyone can help that would be greatly appreciated.

 

[tony the man]

Thank you guys for replying! I bought the car built and the owner ghosted me. When I bought the car one of the injectors clogged up and rusted inside. I ended up buying new injectors same 1300cc but a different brand. I know the car is tuned on some sort of computer but this car is a old build late 2009s. I have no idea what computer its running and I cant seem to find it. But I will surely take a look at all the things you have listed tomorrow.

 

[chrysler kid]

if its sat for ten years with e85 in it then you need to replace all of the fuel lines and fuel injectors