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1G Studder/bucking on accel

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dc320

10+ Year Contributor
89
5
Dec 22, 2011
CARMEL, New_York
I know there are threads on this already. But there are varied answers and conditions for those posts.

If I start my car for the first time, any time of day. If i let it warm for about 5-10 minutes the car will buck and studder like crazy under acceleration. If i let it sit and warm somemore before trying to drive, say 10-20 minute warm up then it is fine.

Say i go to gas station, turn car off for the 5 min it takes to fill gas. Start car and go to drive, will buck and studder on accel. If i let it sit at pump for a few minutes it is fine.

I am going to go outside right after posting this and check plugs, wires, all the little stuff.


I am just trying to get a list of things to check/ change to diagnose this. If my post has confused anyone but you want to help, please dont hesitate to PM me and maybe I can explain better.
 
Says the FPS effects hot starts. Its not starting that is the problem, the car starts no problem. But if I dont let it idle for roughly 5-15 minutes it bucks and studders when i go to drive.
 
Says the FPS effects hot starts. Its not starting that is the problem, the car starts no problem. But if I dont let it idle for roughly 5-15 minutes it bucks and studders when i go to drive.

I'm sorry but you aren't making any sense. There is no context for "Says the FPS effects hot starts". Who or what says this?

Then your second sentence contradicts itself.

You are saying both of these thing in the same sentence:

It's not starting, that is the problem.
&
The car starts no problem.

I am still going with fuel pressure being the culprit. Have you checked this? Or the FPS? Check when warming up and while it's running like shit, then again when it's back to running fine.

What did your plugs look like when you pulled them?

Do you have any way to see live engine data? Misfires and such?
 
That link posted by luv2rally is for hot starts. My issue isnt related to hot starts but starts at any temp.

As i read that sentence I see its confusing, will reword. Car starts with no problem, but if i start it and go to drive right away it studders/bucks. But if i let it warm up for 10-15 minutes after starting it will drive no problem.

Dont have a way to check fuel pressure or FPS unless you dont need a specific tool/device. Hard to explain what the plugs looked like, will try to find a picture from google that looks similar.

Nope no live data programs, car is 100% stock.

PLugs looked like this
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Did all your plugs look like that or only one? Looks lean to me, meaning you are not getting fuel. Included an image below.

Got to the auto parts store and rent a fuel pressure tester. Usually under $30, they will refund you when you bring it back. Situate it in a way that you can leave it connected so you can go drive the car. Zip tie it to something. You want both conditions, running good and running like shit. Be absolutely sure it is not leaking fuel onto the motor, don't wanna burn down your car, that won't help anything. Use teflon tape on connections. See what it says during both conditions and repot back.

Edit: wear some damn safely glasses!


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Between those 3 plugs in the picture, they looked more like the one on the right, except the white part was brown like the left one. I will pull them tomorrow and post a picture.

Got a link on where/how to install the tester? Or can you give me directions on how.
 
Should be a shrader valve on the fuel rail, will look like a valve stem on a tire, where you put air in.

Should just have to screw on one of the fittings from the tester to the valve.

If you don't have a valve then you will have to T into the system. Either way is fairly simple. Google fuel pressure test. Or search here on the forums.
 
On the rail? I will look but im about 70% sure there is none. Never taken notice so i will check.

Since we are on fuel... Would a bad injector do this?

Honestly i am just dumbfounded as to why it only does it when i start the car and go to drive, but if i idle for about 5-10 minutes its fine.

As i read through the manual, I have come across "fast idle air valve" I am starting to think this is bad.

"The fast idle air valve is a wax actuated valve. The engine coolant circulates around the wax pellet.causing the air valve to be forced out as the coolant temperature increases, thus decreasing the bypass air flow rate. The valve is closed completely when the coolant temperature is approximately 50°C (122°F) or higher."

I am not sure what the exact temp of the coolant is, but this sounds like it could be my issue.
 
If it was a single injector then only that plug would have a redish tinge. You could then check that injector by swapping one of the other injectors to that cylinder. If the problem stays with that cylinder, then it would likely be a bad wire. Another way to test injectors is with a multimeter, resistance. I belive should be somewhere around 13-15 ohms. Might wanna do a seach on that one.

It could also be a failing 02 sensor. Some cars computers ignore the 02 sensor on startup though, not sure if yours is one of those.

Could be a bad PCV valve, those are cheap and easy to replace. Usually an odb2 car will show a lean condition when this goes, 1Gs unfortunately has none of that.

Diagnostics by way of forum can be tricky. Have to start with the easiest to test and go from there.

As i read through the manual, I have come across "fast idle air valve" I am starting to think this is bad.

"The fast idle air valve is a wax actuated valve. The engine coolant circulates around the wax pellet.causing the air valve to be forced out as the coolant temperature increases, thus decreasing the bypass air flow rate. The valve is closed completely when the coolant temperature is approximately 50°C (122°F) or higher."

I am not sure what the exact temp of the coolant is, but this sounds like it could be my issue.

Should be able to check that with a noid light or multimeter.

http://m.wikihow.com/Check-an-Idle-Air-Control-Valve

If the top radiator hose is too hot to touch, then the control valve should be doing its business.
 
If it was a single injector then only that plug would have a redish tinge. You could then check that injector by swapping one of the other injectors to that cylinder. If the problem stays with that cylinder, then it would likely be a bad wire. Another way to test injectors is with a multimeter, resistance. I belive should be somewhere around 13-15 ohms. Might wanna do a seach on that one.

It could also be a failing 02 sensor. Some cars computers ignore the 02 sensor on startup though, not sure if yours is one of those.

Could be a bad PCV valve, those are cheap and easy to replace. Usually an odb2 car will show a lean condition when this goes, 1Gs unfortunately has none of that.

Diagnostics by way of forum can be tricky. Have to start with the easiest to test and go from there.

Yea i agree with the forums being hard to diagnose from, appreciate all the help. Not having obd2 honestly sucks LOL, BTW I have not had a check engine light, it works because when i turn the key it lights.
Anyway to check an o2 sensor? Car sat for around 4 years so it honestly can be anything. I am slowly bringing her back to life just trying to get a list of things that would cause this so i am not just blindly replacing things.

Will grab a new pcv tomorrow from autozone, they are real cheap like you said, so I may as well get a new one anyway.

To your second reply.
I will read through that and do the multimeter in the morning.

As for the top hose, it gets hot. I went to lean in after driving the car and touched it a few weeks ago, it didnt tickle LOL.
 
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