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2G 99 GSX Bogging! PLEASE HELP

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bryty22

Probationary Member
9
0
Jan 28, 2019
MOUNT STERLING, Kentucky
To start, I have read all other sources of information that refer to anything with bogging on a 4G63T.
I'm sorry this post will be so long but I know details are key and I want to give you all everything that i know of the car for the best possible answers!!
I will give the full details of the car/mods then the issue.
I purchased this car very recently. To explain this in FULL I will refer to the previous owners and there mods.

Kevin/ Owner from 2015 thru November 2018
1. New Timing Belt
2. New stock Turbo
3. Replaced Water Pump
4. EGR Block Off

Apparently Kevin sells the car because it is no longer running and he does not know the issue.

Daniel/ Owner from November 2018 thru January 2019 (I bought the car from Daniel)
1. Walbro 450 e85 Fuel Pump
2. 101-100/101-200 cams (says completely new, I will include a picture he sent of them before I purchased)
3. NGK bpr6es spark plugs
4. Coil Pack
5. NGK Plug Wires
6. Oil Change

Daniel tells me he purchased the car not running and all he did was put a fuel pump on it and it started right up.
Daniel also tells me he has removed the A\C compressor and lines along with removing cruise control.
He has also cut of the exhaust directly behind the cat-converter

BUYING/ DRIVING HOME
I live in Kentucky and Daniel lives in Kansas. I found the car via craigslist a mere few hours after it was posted (I searched for these cars daily nationwide.... been wanting a 99 GSX for a while LOL)
I drove to Kansas 630 miles away, and looked at the car. Upon arrival had to jump the car because Daniel said he had left the light on. Started right up tho and idled fine. (just loud) let it warm up for a moment and took it for a short test drive. (keeping in mind the temp is 15 degrees) Car ran great. Everything worked from the power seats, sunroof, to the heat. Put the car to the floor and it accelerated and rev'd completely fine.
Daniel gave me the Cat and o2 sensor he had cut off, He also gave me the cruise control, A/C compressor and lines.
After agreeing to buy the car I started the 9 hour drive home. Car still running fine. 30 minutes into driving we pull over to nap for a bit. 1 and a half hours later (the car was completely turned off during this whole time as we napped in the car we drove down in.) I wake up, fill the car with gas and hit the interstate. First chance I got to give the car full throttle, I did. BOOM!! Back fired really loud, bogging hard and no acceleration. I let off throttle and hit it again. Same thing. Car is running and driving very well other than when attempting to give it enough throttle to build boost. I continue my drive home and the problem continues the entire drive. During the drive home by feathering the throttle i was able to hit 105mph (anymore throttle was causing rpms to spike and the bogging would begin.)

Fast Forward to being home
I have done the following and the problem still persists.
1. Checked for visible obvious boost leaks
2. New Fuel Filter
3. Checked all Spark Plugs
4. Cleaned MAF Sensor
5. Oil Change
6. Reinstalled Cat-Converter and rear o2 sesnor

The car has actually gotten progressively worse. Ill explain my results by relating the #1-#6 i listed above and describe the car after each.

1-2
Car had no visible or obvious boost looks. All hoses and connections seem to be intact and tight. New Duralast direct fit fuel filter.
Car idles 1000rpms, runs and drives the same. (60-70mph is as fast as you can go now matter how you accelerate)

3-4
Spark plugs all looked good. Used MAF sensor cleaner.
Car idles 1000rpms, runs and drives the same.
While the car is running if you unplug the MAF sensor it bogs down hard at idle but seems to drive the same plugged in or not.
Still cant get past the 60-70mph

5-6
Had a local shop change the oil and put the cat back on. They also replaced the flex joint (old one had a small hole) They plugged up the rear o2 sensor as well.
Car idles rough at 500rpms, runs betterish, drives the same.
While driving and under decent throttle you still get the bogging really bad and the car does not accelerate at WOT. Plus side, you can give the car moderate throttle for a little quicker acceleration as opposed to literally having to feather it before.
65mph MAX
***Mechanic said the Cat had a crack on the inside

I have driven many turbo cars and had a 99 gst previously. This car is not getting boost under throttle at all or it definitely doesn't feel or accelerate like it is. You can definitely here the turbo begin to spool under slight throttle but then the bogging starts soon after. Also keeping in mind during all 6 things I have done thus far at idle you can rev the car to 7k rpms. sometimes it cuts out, sometimes it doesn't. The car currently has no gauges at all so I cant actually tel if it is building boost or not.

1999 Eclipse GSX
141,000 miles
Automatic

The car is currently reading the following codes when scanned
I have researched all of these codes via obd-codes.com and answered all of the possible causes that they list.
P0125 ENGINE COOLANT TEMP SENSOR
-Car seems to warm up fine
-Coolant level is fine
-Car does not have any visible leaks
-HAVE NOT tested coolant temp sensor
P0136 2nd o2 sensor on Bank #1
-NOT BEEN CLEARED SENSE REINSTALL OF CAT
P0141 HEATED CIRCUIT o2 Sensor 2 on Bank #1
-NOT BEEN CLEARED SENSE REINSTALL OF CAT
P0170 FUEL TRIM
-CEL is on
-Idles at 500rpm
-Awful MPG
-No black smoke
-Hesitates at idle and under load
P0403 EGR CIRCUIT
-Supposedly blocked off by Kevin (DONT KNOW HOW TO CHECK)
P0443 PURGE SOLENOID
-NO IDEA on anything here
P1104 TURBO WASTEGATE SOLENOID
-When giving throttle in park the wastegate doesnt move???
P1105 FUEL PRESSURE SOLENOID
-NO IDEA here

I will have the car rescanned this evening and all codes cleared. I'll report back with the remaining codes.

Any input, feedback, or suggestions at all would be extremely appreciated!!!!
Thank you all in advance!
 

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There's two on the thermostat housing. One is for the gauge cluster, the other is for the ecu. Replace the one for the ecu and inspect the wiring around the plug that goes into the sensor, those seem to fall apart over the years.
 
There's two on the thermostat housing. One is for the gauge cluster, the other is for the ecu. Replace the one for the ecu and inspect the wiring around the plug that goes into the sensor, those seem to fall apart over the years.
Just called my local O'Reilly and they have 2 "coolant temp sensors" in stock. They said both are different. So I'm guessing they have one of each..??
Should I just get both?
Are these hard to swap out?
 
The temp sensor is easy to replace. It's a 2 wire connector and is screwed into the passenger side thermostat housing under the cap.

You need to do a REAL boost leak test. A visual inspection tells you nothing more that clamps haven't popped off. I've done visual inspections that look 100% and then boost leak test and the coupler literally falls off a pipe. It sounds like you have a boost leak, unhooking the MAF and having similar driveabilty under load leads me to believe that even more.
 
The temp sensor is easy to replace. It's a 2 wire connector and is screwed into the passenger side thermostat housing under the cap.

You need to do a REAL boost leak test. A visual inspection tells you nothing more that clamps haven't popped off. I've done visual inspections that look 100% and then boost leak test and the coupler literally falls off a pipe. It sounds like you have a boost leak, unhooking the MAF and having similar driveabilty under load leads me to believe that even more.
I'll replace the temp sensor this evening (both of them most likely)
Any ideas of how I can do a boost leak test myself? I don't have a compressor.
 
Yeah, the coolant temp sensor will really mess the car up if it's bad. Also, I was under the impression that you shouldn't use maf cleaners with our maf. I'm 50/50 on that maybe you caused some damage. I'd do a search on that. Can't believe you drove that thing 9 hours home. Holy hell you got lucky to make it that far on a Craigslist car.
 
Yeah, the coolant temp sensor will really mess the car up if it's bad. Also, I was under the impression that you shouldn't use maf cleaners with our maf. I'm 50/50 on that maybe you caused some damage. I'd do a search on that. Can't believe you drove that thing 9 hours home. Holy hell you got lucky to make it that far on a Craigslist car.
The MAF sensor cleaner was just an effort to help. I actually ordered a new MAF sensor and it will be picked up this evening along with the coolant temp sensors!
 
I'll replace the temp sensor this evening (both of them most likely)
Any ideas of how I can do a boost leak test myself? I don't have a compressor.

Find a friend with one, buy one, or how I did it when i was young/broke- find a gas station with free air. I wouldn't bother replacing both, one is simply a single spade wire sensor for the gauge and has zero effect on anything other than the gauge.

Yeah, the coolant temp sensor will really mess the car up if it's bad. Also, I was under the impression that you shouldn't use maf cleaners with our maf. I'm 50/50 on that maybe you caused some damage. I'd do a search on that. Can't believe you drove that thing 9 hours home. Holy hell you got lucky to make it that far on a Craigslist car.

You're correct. We have karman vortex sensors that aren't meant to be cleaned. MAF cleaner works on GM style hot wire sensors, but not karman vortex and can mess them up using it.
 
I would join the local dsm Facebook group and ask if you can drive to someone's house and do I there.
Unfortunately in my area there is no DSM group. basically no car scene at all. Only diesel turcks.....
 
Find a friend with one, buy one, or how I did it when i was young/broke- find a gas station with free air. I wouldn't bother replacing both, one is simply a single spade wire sensor for the gauge and has zero effect on anything other than the gauge.



You're correct. We have karman vortex sensors that aren't meant to be cleaned. MAF cleaner works on GM style hot wire sensors, but not karman vortex and can mess them up using it.
I'll do my best to boost leak test the car tonight!!

Found the thermostat housing on google. just to confirm, Ill want to replace the black connection plug?
 

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I'll do my best to boost leak test the car tonight!!

Found the thermostat housing on google. just to confirm, Ill want to replace the black connection plug?
Correct. The parts store may try selling you one with spade terminals instead of an actual connector like that. It's a 1g sensor if so, not the correct sensor, make sure you get the same as the one pictured.
 
how much boost are you running on that stock turbo . maybe it's to high and your ecu is trying to shut the engine down . try lowering your boost and see what happens.
 
First off why would you buy a car thats a cluster and then be flooring it on the highway and winding it up over 100mph without knowing anything about it??? super dumb and irresponsible on your part, that kind of stuff can cost lives and or major damage. Now that Ive said that, it sounds like a boost leak to me.
 
how much boost are you running on that stock turbo . maybe it's to high and your ecu is trying to shut the engine down . try lowering your boost and see what happens.
Currently the car has nothing other than the stock "boost" gauge. From what I have read these are extremely unreliable in terms of interpreting lbs of boost. So to answer your question, I currently dont know.
 
I appreciate everyone's replies thus far!
Last night I installed the new coolant temp sensor (duralast, direct fit) Inspected the connector plug to the sensor and all seemed well, all wires were intact and no corrosion at all.
I also installed a new MAF sensor.
At this point I started the car to see how it did.
Idle was much more normal for a cold start at around 2k rpms (3 degrees outside) when warmed up around 1k rpms at idle. Now to drive it.... When the car hits gear the rpms immediately drop to the 500-800 range and often lope.
Driving the car, still acts the exact same. I can use about half throttle for 10 seconds and have mild acceleration, after that the bogging starts. Also full throttle from a dead stop does absolutely nothing and the car just slowly accelerates until bogging shortly after.

*******I attempted a boost leak test but the compressor I used had a faulty hose and was basically just spraying air. Keeping in mind that my knowledge of cars is minimal and on this engine especially. So I dont really even know how to do a boost leak test. i.e. if i send air thru the turbo directly do I need to cap it off somewhere else? Where all do I check for leaks?

When looking over the car (seeing countless videos and pictures on the net and comparing the engine bay to mine) it leaves me with some concerns. For example.. (see picture)
Is it normal and okay to see these 2 positions capped off? Does the other line actually go to the valve cover? (One video I seen the valve cover line did not connect to the MAF.

I have not yet been able to clear the codes since the cat-converter, o2 sensor, MAF sensor, and coolant temp sensor have been replaced.

The direction and orientation of the MAF in this pic is as if you were standing directly in front of the engine bay looking down.
 

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Aha, I see what's going on here.

1. You have a 450 fuel pump. You're probably overrunning the fuel pressure regulator and the car could be extremely rich. Do you have an aftermarket fpr? If not, you'll need to get one to tone down the fuel pressure. Do a search on 2g dsm with 450 pump.

2. You need to hook up the intake/maf as described in that picture.

3. There are literally thousands of videos on how to do a boost leak test. Do it at the turbo for now.

Do these things and check back.
 
Why are you throwing Parts at the car? Get a Data Logger and find out what the car is doing. If this is a stock untuned car with no method of fuel control the previous posts are correct that fuel pump is entirely too large. You need to know your air fuel ratio. Is the mechanical timing correct. What cams are actually in the car. Are all the lines that should be hooked up actually hooked up. Do a proper boost leak test. Do a proper boost leak test. Do a proper boost leak test. At the very least get an OBD2 Data Logger and look at basic functions of the car. If this car does not have an aftermarket fuel regulator you will have to pull that pump. I'm wondering if the previous owner was running E85 and it happened to run reasonably well accidentally. E85 requires more fuel. Do you see where I'm going here?
 
It really sounds fueling related, in closed loop it sounds like it does ok, with O2 & ecm trimming the fuel the best it can, but at high enough throttle/load where you hit open loop it takes a dump.
Without enough experience with the car & somebody close by that has experience you need a scan tool of some sort to read things like fuel trims, error codes, sensor data to help make a determination.
At least go through and physically check, not eyeball, all hoses & connection points from the turbo outlet to the throttle body elbow for anything odd.
 
Why are you throwing Parts at the car? Get a Data Logger and find out what the car is doing. If this is a stock untuned car with no method of fuel control the previous posts are correct that fuel pump is entirely too large. You need to know your air fuel ratio. Is the mechanical timing correct. What cams are actually in the car. Are all the lines that should be hooked up actually hooked up. Do a proper boost leak test. Do a proper boost leak test. Do a proper boost leak test. At the very least get an OBD2 Data Logger and look at basic functions of the car. If this car does not have an aftermarket fuel regulator you will have to pull that pump. I'm wondering if the previous owner was running E85 and it happened to run reasonably well accidentally. E85 requires more fuel. Do you see where I'm going here?

A 450 pump WILL overrun the fpr, stock or any flavor, if the return siphon mod is not done. So I'd look into that as the very next thing. That would also cause havoc on it actually rising 1:1 which will have you pulling your hair out.

If the car doesn't have a logger, safc, or 'link, I wouldn't factor in e85 ever being part of the equation.

While you can't really mess up the base ignition timing on a 2g unless it's REALLY off, the cams have me concerned. HK$ are the only drop in and forget it cams I know of. Whatever OP has could be a few degrees off either way on either one, and if so, will cause him all kinds of grief.
 
I ran a Toyota supra fuel pump with no updated regulator for a long time with no problem until i rewired the fuel pump . looking again at this problem it does sound like a boost leak .
 
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