2G 1998 Eclipse GST ran good, now low idle and wants to die.

[Kniesy]

How’s it going, I have a 98 Eclipse GST 5 speed and it was running fine till I went to drive home a few hours later. It had a rough idle and low idle and when giving it more throttle made it choppy as well. Putting it into neutral, the RPM’s would drop all the way down and the motor would die.

Trying to figure out if this is a fuel related symptom or a boost leak or something else.

It was doing this after sitting for a few hours and now is has a low idle on cold start which it didn’t have before. I am new to these cars.

New plugs/wires
New IAC
New fuel filter
New air filter

It’s mainly stock with a 164k miles, supposedly has a 16g not sure the brand
Has no over heating problems or CELs. Had one code P1105 fuel pressure solenoid circuit awhile ago but hasn’t come on since.

Any help would be appreciated thanks!

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[chrysler kid]

Most likely you have a bad vacuum leak
You can verify this by unplugging the mass air flow sensor and starting the car. If it runs better with the mass air flow sensor unhooked it is because the map sensor is more accurately reading air coming into the intake manifold.

There are several places it can leak air from to cause a bad idle. You should also listen for a hiss noise at idle to help you find the leak


Is that a current picture of the engine bay since the issue started? If not can you take a new picture

The best way to find your issue is a boost leak test, or a smoke test

 

[Kniesy]

Most likely you have a bad vacuum leak
You can verify this by unplugging the mass air flow sensor and starting the car. If it runs better with the mass air flow sensor unhooked it is because the map sensor is more accurately reading air coming into the intake manifold.

There are several places it can leak air from to cause a bad idle. You should also listen for a hiss noise at idle to help you find the leak


Is that a current picture of the engine bay since the issue started? If not can you take a new picture

The best way to find your issue is a boost leak test, or a smoke test

Ok I will check that out and yea that’s the current picture, just seeing what you would recommend doing, trying to find a metal pipe to replace that throttle body braided hose. Any recommendation I’m all ears, just trying to do maintenance and keep it stock basically

 

[chrysler kid]

I am using a cx racing intercooler piping kit. They use to be $150 on ebay, but now you have to pay $210 for them on cxracings website.

Its a good upgrade, the turbocharger will spool noticeably faster. It was one of the first "mods" I did. I consider it more of a maintenance modification than performance mod, since the stock rubber intercooler hoses flex pretty badly when they are worn

I painted them black to look stock, I also trimmed an ebay intake and painted it black to fit behind the stock air box to make everything look stock

You must be logged in to view this image or video.

 

[Kniesy]

I am using a cx racing intercooler piping kit. They use to be $150 on ebay, but now you have to pay $210 for them on cxracings website.

Its a good upgrade, the turbocharger will spool noticeably faster. It was one of the first "mods" I did. I consider it more of a maintenance modification than performance mod, since the stock rubber intercooler hoses flex pretty badly when they are worn

I painted them black to look stock, I also trimmed an ebay intake and painted it black to fit behind the stock air box to make everything look stock

You must be logged in to view this image or video.

Is that kit for stock intercooler not FMIC, was gonna replace coolant lines with new silicone ones, might just replaced the MAF with a newer one cause of age. I don’t mind replacing maintenance stuff cause of age and no history of when it has been replaced before

 

[SixBolt_16G]

Is that kit for stock intercooler not FMIC, was gonna replace coolant lines with new silicone ones, might just replaced the MAF with a newer one cause of age. I don’t mind replacing maintenance stuff cause of age and no history of when it has been replaced before

Yes, they do have a kit for the stock intercooler.


I just replaced my coolant lines with silicone too. Some good advice that I got from here before I started removing the heater hoses was to not pull them off because the spouts coming off the heater core can bend easily. Take a razor and slice them long ways along the spout and theyll just come off easily

 

[chrysler kid]

Is that kit for stock intercooler not FMIC, was gonna replace coolant lines with new silicone ones, might just replaced the MAF with a newer one cause of age. I don’t mind replacing maintenance stuff cause of age and no history of when it has been replaced before

Its a stock replacement side mount intercooler piping kit. It is a replacement for the stock intercooler piping on t25 car

I have black silicon hoses to remain looking stock looking. They are a great replacement, especially for your factory heater hoses.

However do not under any circumstance "upgrade" to an aluminum radiator, always use a stock replacement radiator. The aluminum dual cores are not as effective as factory when it comes to the fans removing the heat from the core

 

[Kniesy]

Yes, they do have a kit for the stock intercooler. Should be this one..

CX Racing intercooler piping

Correct, @chrysler kid ?

I just replaced my coolant lines with silicone too. Some good advice that I got from here before I started removing the heater hoses was to not pull them off because the spouts coming off the heater core can bend easily. Take a razor and slice them long ways along the spout and theyll just come off easily

is there a way to see which turbo I have like size wise, anything on the actual turbo itself,

 

[SixBolt_16G]

is there a way to see which turbo I have like size wise, anything on the actual turbo itself,

Im sorry, I missed your profile saying that you have a 16g and looking at the pic of your engine bay, it looks like you have a Jpipe coming out of the top of the compressor... so you would need this piping instead for td05.

CX Racing intercooler piping(td05)
From the description:
*This Kit Replaces the Stock Intercooler Piping, Hose and Clamps. But Keeps Stock BOV and Stock SM Intercooler.

 

[chrysler kid]

Im sorry, I missed your profile saying that you have a 16g and looking at the pic of your engine bay, it looks like you have a Jpipe coming out of the top of the compressor... so you would need this piping instead for td05.

CX Racing intercooler piping(td05)
From the description:
*This Kit Replaces the Stock Intercooler Piping, Hose and Clamps. But Keeps Stock BOV and Stock SM Intercooler.

Yeah thats the kit I have.

The only difference is the lower intercooler pipe on the t25 style is flat, he needs that one you have linked for the jpipe on the 14b or 16g

 

[chrysler kid]

is there a way to see which turbo I have like size wise, anything on the actual turbo itself,

Yes if you unhook the intake boot to the mass airflow sensor and take a picture of the face of the turbo we will be able to see identification stamps on the front of the turbo

If it says td05 on the front face of the turbo its an original mitsubishi style turbo.

If it has a flat square bulge where there is an inscription that says 16g its an ebay turbo

Here's a picture of the face of an ebay turbo

You must be logged in to view this image or video.

Here's a front face of a factory mitsubishi turbo

You must be logged in to view this image or video.

 

[Kniesy]

Awesome info, I will let you guys know soon! I will see how it starts with the MAF sensor unplugged

 

[Kniesy]

Yea for sure an eBay 16g and the intake clamp was pretty loose it just came right off. Started and immediately dies with the sensor plugged and unplugged

 

[Kniesy]

You must be logged in to view this image or video.

 

[Kniesy]

You must be logged in to view this image or video.

 

[Kniesy]

You must be logged in to view this image or video.

Shouldn’t look wet in the intake unless it’s an condensation thing

 

[Kniesy]

Shouldn’t look wet in the intake unless it’s an condensation thing

You must be logged in to view this image or video.

 

[Kniesy]

You must be logged in to view this image or video.

Has an oil residue

 

[Kniesy]

There’s a random bolt in that welded thread on the j pipe I’m sure that a good boost leak

 

[Kniesy]

There’s a random bolt in that welded thread on the j pipe I’m sure that a good boost leak

You must be logged in to view this image or video.

 

[Kniesy]

Yes if you unhook the intake boot to the mass airflow sensor and take a picture of the face of the turbo we will be able to see identification stamps on the front of the turbo

If it says td05 on the front face of the turbo its an original mitsubishi style turbo.

If it has a flat square bulge where there is an inscription that says 16g its an ebay turbo

Here's a picture of the face of an ebay turbo

You must be logged in to view this image or video.

Here's a front face of a factory mitsubishi turbo

You must be logged in to view this image or video.

Update, so basically cold start it will run fine then I let it sit for about an hour or so went to start it back up and it runs a little rough and giving it throttle runs a little rough as well. Will a vacuum or boost leak make it run different between a cold start and warm start.

Since I already have hard pipes on the bottom end do I need to buy the kit to just get the throttle body pipe and not sure if the kit will work with the HKS BOV since the stock pipe is an inlet and that CX racing kit has the inlet with the flange unless I’m missing something

 

[chrysler kid]

Update, so basically cold start it will run fine then I let it sit for about an hour or so went to start it back up and it runs a little rough and giving it throttle runs a little rough as well. Will a vacuum or boost leak make it run different between a cold start and warm start.

Since I already have hard pipes on the bottom end do I need to buy the kit to just get the throttle body pipe and not sure if the kit will work with the HKS BOV since the stock pipe is an inlet and that CX racing kit has the inlet with the flange unless I’m missing something

Hmm, wierd hunch.

There is alot of oil on and around the turbo, which makes me think the valve cover gasket is leaking. The valve cover gasket is also hooked to the breather going to the intake, and the pcv valve also draws a high amount of vacuum from the valve cover

Its possible that the breather hose and the pcv valve sucking air through the valve cover is causing a vacuum leak.

You could cap the vacuum nipple on the intake manifold, and cap the nipple on the intake boot to see if that cures the idle issue. Or just replace the valve cover gasket since it seems to be leaking

Also im not concearned with oil in the intercooler piping or in the intake, or in the turbo. These cars typically have high crank case pressure and like to vent that pressure back through the valve cover and back into the intake and back into the turbo. So oil residue is normal on the intake side of the turbo

If it really bothers you, you can run a catch can, but Im the wierd type of person who thinks extra oil isnt a terrible thing

 

[Kniesy]

Hmm, wierd hunch.

There is alot of oil on and around the turbo, which makes me think the valve cover gasket is leaking. The valve cover gasket is also hooked to the breather going to the intake, and the pcv valve also draws a high amount of vacuum from the valve cover

Its possible that the breather hose and the pcv valve sucking air through the valve cover is causing a vacuum leak.

You could cap the vacuum nipple on the intake manifold, and cap the nipple on the intake boot to see if that cures the idle issue. Or just replace the valve cover gasket since it seems to be leaking

Also im not concearned with oil in the intercooler piping or in the intake, or in the turbo. These cars typically have high crank case pressure and like to vent that pressure back through the valve cover and back into the intake and back into the turbo. So oil residue is normal on the intake side of the turbo

If it really bothers you, you can run a catch can, but Im the wierd type of person who thinks extra oil isnt a terrible thing

Yea I saw i had a little pool of oil inside the valve cover on the top part but not in the spark plug tubes I have to see if there’s a crack on the top end of it cause I don’t see how oil would be leaking from the gasket into there

You must be logged in to view this image or video.

 

[Kniesy]

Hmm, wierd hunch.

There is alot of oil on and around the turbo, which makes me think the valve cover gasket is leaking. The valve cover gasket is also hooked to the breather going to the intake, and the pcv valve also draws a high amount of vacuum from the valve cover

Its possible that the breather hose and the pcv valve sucking air through the valve cover is causing a vacuum leak.

You could cap the vacuum nipple on the intake manifold, and cap the nipple on the intake boot to see if that cures the idle issue. Or just replace the valve cover gasket since it seems to be leaking

Also im not concearned with oil in the intercooler piping or in the intake, or in the turbo. These cars typically have high crank case pressure and like to vent that pressure back through the valve cover and back into the intake and back into the turbo. So oil residue is normal on the intake side of the turbo

If it really bothers you, you can run a catch can, but Im the wierd type of person who thinks extra oil isnt a terrible thing

Runs perfect on cold start and drives great, just when it sits for a couple hours it goes to crap

You must be logged in to view this image or video.

 

[chrysler kid]

The oil in the plug valley is from the oil cap

Im talking about the oil leaking from the edges of the valve cover onto the thermostat housing and turbo

Seems like its running fine. Have you taken off the heat shield to make sure the exhaust manifold isn't cracked