420a sputtering at mid throttle

[Talon856]

hey guys I have a 1995 talon 420a first second gen. And I am having a issue. When I go up a hill or drive for a extended period of time when I am in lite or mid throttle it hesitates and surges. It's randomly not a quick sputter. So I am pretty sure it's not ignition. Plugs are new and the spark has been tested hot and cold and they do great. Have fuel pressure. And I was running a on board tool and noticed that the timing would drop a lot when it sputter anyone please help thanks.

 

[Dstarperformance01]

Check tps

 

[Talon856]

Just replaced tps last night still doing it. But it's weird cause it's sitting at 16 percent at idle and wot is only 77%

 

[Dstarperformance01]

Needs to be adjusted possibly and throttle cable may need adjusting for that issue. Any codes when it does it? Watch as much data as you can while getting it to "miss/sputter". What are the condition of the spark plug wires? Possibly arcing when it's happening.

 

[Talon856]

Okay so I watch it and when it sputters the timing will be at 30 degrees advance and then it will sputter and the timing drops down to like 3 degrees then back up. You think plugs wires can be the cause of that? And how do you adjust the tps sensor?

 

[Talon856]

How do you adjust the tps sensor? And also I was watching it and when it starts sputtering I see the timing jump down from like 30 degrees down to like 2 the back up. What would mess with your timing and sputter like that?

 

[Murdertalon]

Something that may have been overlooked is when was the fuel filter last replaced? I would replace it if you don't know. I replaced mine and I could barley blow though the old one/ it was past needing changed. Check the air filter and possibly the CAT as well.

 

[Talon856]

Just did fuel filter, cold air intake aem. What the cat?

 

[Macgyver'sDSM]

He is referring to a catalytic converter.

 

[Murdertalon]

Yeah if your car can't breathe properly it will fall on its face I had a 1g neon that had a bad cat on it, it was restricting flow badly and it didn't like wot and mid throttle would struggle.

 

[Macgyver'sDSM]

A cloged catalytic converter normally causes a drop in power most noticeable at full throttle and is normally present all the time under large throttle inputs. And yes bad plug wires can cause a random miss that may cause the ecu to pull timeing. But not having a correct tps reading is a problem. If you have a multimeter you should begin by checking the tps for proper voltage and adjusting it. If you use the search feature there are plenty of threads on that available on this site. If your tps checks out ok by hand make shure to verify that it also does the same when pushing the gas pedal. If not then there may be a problem with your throttle cable or linkage.

 

[Talon856]

I pulled the cat off and checked it and I can see through it. It's not burnt or melted at all. I replaced the wires still no luck. I will have to do research on here to see how to adjust the tps. It isn't able to move back and forth there are just two bolt holes. My computer says it's at 12% throttle at a idle and 76% at wot. Can the cas drop timing if it was bad? Or the knock sensor read fantom knock if it was bad and pull timing? I know my 1g tsi did that when it was bad.

 

[Murdertalon]

My throttle cable was well out of adjustment and my tps would read 8% idle, I had to add springs to it so it snaps shut now. It's a temporary fix I'll rebuild the throttle body later. I also saw 75% at wot and I had to shim the pedal cable at the pedal to open it all the way even after adjusting it on the threaded bolts.

 

[Dstarperformance01]

Needs to be adjusted possibly and throttle cable may need adjusting for that issue. Any codes when it does it? Watch as much data as you can while getting it to "miss/sputter". What are the condition of the spark plug wires? Possibly arcing when it's happening.[/QUOTE

My throttle cable was well out of adjustment and my tips would read 8% idle, I had to add springs to it so it snaps shut now. It's a temporary fix I'll rebuild the throttle body later. I also saw 75% at wot and I had to shim the pedal cable

I said that in the 4th post

 

[Talon856]

Are you saying I may need a new cable?

 

[Dstarperformance01]

I said to inspect it as well as check tps adjustment. You shouldn't have to shim a factory cable unless it's a custom set up job or its worn out. That's all. Side note, have you done an injector kill test to see if it's injector related?

 

[Talon856]

Okay I did some more digging and the timing in on, tps is set, coil pack, wires, spark plugs are replaced. I am getting the code 1391 intermittent lose of ckp. I was wondering before i shotgun sensors at it. is there supposed to be oil on the backside of your cas? or is that why they have an o ring on it. i just know that it is a magnetic sensor and couldn't think that would be good on it, or i could be 100% wrong. also i am deleting the cat. I did some data logging and the rear 02 sensor is fallowing the front voltage which is a sign of a plugged cat. So that are my two only things i have left to check that would cause it to surge and drop timing and pull fuel out of the short turn fuel trims. I also have ohms tested the wires that go to all the sensors and they all are great connection and have no breaks. so I guess that is the last question before i go ahead and shotgun sensors to it.

 

[Dstarperformance01]

Ckp is crank position sensor. It will cause your issue.