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2G 2g gsx will not run right

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Mttwnsck

Probationary Member
11
0
Feb 20, 2018
west Wyoming, Pennsylvania
I bought a 99 gsx a few months back, the car needed a head gasket. I replaced the head gasket, water pump, timing belt, all silicon couplers, new exhaust, aem gauges etc. Well 3 days after having the car on the road the head gasket blew again, turns out the head was warped be between cylinders 2 and 3. I had the head resurfaced installed a oem composite hg, oem intake, exhuast gasket and injector seals. When I got the car all together and running again it ran great for about 15 minutes and then shut off, tried it again and everytime the car would get warm it would shut off, check the code came up for the cam sensor. I replaced the sensor car ran good till it got warm again, this time it would run rough, I went over all vacuum lines, all the wiring and timing, all was good. Today after work I double checked everything, when I started the car it would start then shut off, so I put the old cam sensor back in car started right up ran great for about 10 minutes untill warmed up again then shut off, so I tried the new sensor it ran and did not shut off but it ran rough, tried to take it for a drive hoping it would just clear out and couldn't even back out of the garage. I did notice that the injectors seem to be ticking louder than before. I am going to do a boost leak test tommorow and change the plugs, I'm not sure where to go from there, also has a brand new crank sensor old one was damaged, and I did look at the computer it looks fine If ayone has any ideas or can point me in the right direction it will be very appreciated. Thank you in advance
 
In my opinion you need a scanner. You need to see if cam and crank sensor are loosing sync. You also need to graph coolant temp sensor and see if it don't drop out or any other sensors drop out. I had in the past a 2011 6.0 Tahoe and it went thru few shops. Every shop changed something so by the time it got to me I was running out of ideas. Sometimes the car run super rich. Pegs fuel trim on bank 2. Cat cherry red. Run for few minutes and then die and don't want to restart. Spend 3 days on it and by chance I checked the ground on coils on bank 1 and compared it to bank 2 and it was off. Turn out to be a simple fix by repairing a ground. So the moral of the story is this. Don't run out of ideas just step back and go over what you have. I strongly advice to use a scanner. Try to see what is happening and what is dropping out or going out or range. Monitor crank sensor, cam sensor, cam/crank correlation(must sync)fuel trims, coolant temp, mas. Go back to the car and check ground on cam sensors, 5 volt reference and compare to outer sensors. If the problem to be believed in crank/cam sensors then try to put a scope on signal line and see the patern. That's the direction I would take. Maybe others have ideas. Post back with what you find.
 
Sounds like the crank sensor to me, but I can't know that for sure. I've had several crank sensor failures on various vehicles that only fail when warmed up, then the vehicle dies and becomes a no start until it's cooled down. But your car isn't at my shop to put a lab scope on and watch the signal during its failed state. The best thing I can recommend is to get a hand held scanner that can show you live data and watch the engine rpms until the problem occurs and see if rpm drops out. If so, it's gonna need a crank sensor behind the timing belt on the crank sprocket.
 
Brembo you posted as I wrote my response! I think we are on the same page. Op needs to see data for this one.
 
Ok I do not have a scope I will have to find one. I'm going to have a buddy bring his scanner over when I get out of work and I will post back with what I find. I forgot to mention that when the head was off the car and I was cleaning and inspecting it I told the head on the sensor causing it to crack and where the plugs plugs in was loose, is it possible to have just gotten a bad sensor, and also I will also monitor my wideband to see if there's a spike in afr.
 
Ok I do not have a scope I will have to find one. I'm going to have a buddy bring his scanner over when I get out of work and I will post back with what I find. I forgot to mention that when the head was off the car and I was cleaning and inspecting it I told the head on the sensor causing it to crack and where the plugs plugs in was loose, is it possible to have just gotten a bad sensor, and also I will also monitor my wideband to see if there's a spike in afr.

Yea it is possible. I have once changed the vehicle speed sensor on Kia mini van and it was undrivable after repair. I was like WTF. So I scoped the new sensor and the thing was dropping out more then old bad sensor. So yes it is possible. It is also possible that the problem was there all along but now you have disturbed it and it is giving you problems. Story of my life. We usually say in my shop "it was good until you touched it". Also tap test works great on cam/crank sensors. Good luck.
 
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Ok so I swapped the cam sensor for a diffrent one and put in ngk bpr6es plugs, ran choppy at first, that had now cleared up seems to be good besides the idle surging a little bit. I am going to let it run a little bit longer and try to take it for a test drive
 
Ok so the test drive went good the only thing I did was disconnect my boost gauge. It's wired to pin 25 I belive on the ecu because it needs constant switched power could that be messing with the computer?
 
I don't know what pin 25 is for but the way I see is if it's digital gauge and you are logging it then you need to verify if that's where you have to be taped in. If you are not logging it then disconnect it right awey. You can get power source from somewhere else. You never want to pull power from pcm to power up anything. Pcm is only a brain. Period.
 
Ok I will do that. The only reason I did was because I didn't know where a switched 12v the kept power during crank was and I read in the formus to wire it in there. Well thankfully the car is back up and thank you for the input
 
I checked the trigger plate a while back when I first got the car and had issues
 
I am now having the problem where the car runs amazing untill i shut it off then it will start, run for a few seconds then shut off as if you turned the key. Will not start and stay running until cold agin.
 
I am now having the problem where the car runs amazing untill i shut it off then it will start, run for a few seconds then shut off as if you turned the key. Will not start and stay running until cold agin.

That can be a problem with the fuel pressure regulator solenoid on the firewall not being connected to the fuel pressure regulator

These cars can boil the fuel in the rail and create fuel vapor lock, where the vapors stay in the rail at the highest point, while the fuel goes under the vapor and out through the the regulator.

My car even with the regulator hooked up can idle a bit lumpy on a quick turn off and re turn on at a gas station on a hot day
 
Is there a way to bypass it. To test it to see if thats it. I did not have this problem until I changed the head gasket
 
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