Engine/Transmission (1998.5 - 2002) Truck has miss only with edge on ( test results)

[timbo]

Let me explain the miss again, this is most noticable in 4th or 5th gear, cruising low in the RPM band ( about 1300 RPM) and nail it, the RPM band is pretty rough, I can see it in shifter( bucking) until about 2500, then it is smooth til Redline. So I tried a few tests the IAT sensor measures the temp of the intake air,and defuels ( maybe retards timing) according to air temp. I got specs on the sensor at Geno's. The OHM range is between 40K at 30 degrees to 675 OHM at 212 degrees. So I had an adjustable resistor, I unplugged the connector and made up a pigtail to plug in the resistor, dialed at 675 OHMS and went for a drive, it got BETTER, but was still there, but not as bad. Then I adjusted it to 30K, the computer would then think it was cold (32 degrees), the miss was back full force again. I then just plugged the sensor back in. Next I got some Bio Fuel and tried about 25%, went for a drive, and it was better, but was still noticeable. All I can do is make it better, nothing "CURES" it yet, but still trying. One thing for certain, it's much worse when i leave in the morning @30 degrees then when i come home in the afternoon @60deg. My jammer 2s got here today, i really hate to take the 4s out but it may come to that if i have to. I was also thinking about putting my water/Meth set-up off my mustang on it, just to see if it's better or worse. Never know somtimes!

 

[Yooper1]

This is a on going problem with the colder temp's. when it's warm the miss is gone. Right? My 01 does it only when it's cold, (below 40) With the comp on.

 

[KDoerr]

It is most likely the APPS sensor that is going. I have done 3 APPS sensors and they did it all as you are explaining with the bucking. did you have it when you try to pass and you get no throttle responds? If yes it is definitely the APPS.



Good Luck



Keith

 

[timbo]

Never had any dead petal or accelerator response issues, it's only with the box on. Also problem occured after injector install. If i had another apps i would try it but i don't and its a pretty pricey unit!

 

[GOT-Torque]

I myself am convinced it is timing related only. More fuel just makes it more noticeable. It's too bad an edge comp box doesn't come with a dial to adjust timing from stock level to the advanced level. This would allow each individual to dial back the timing as needed based upon air temps. Just a thought...



I wonder if guys running a smarty instead of an edge box experience the same thing when a fuel and timing mode is entered as compared to a fuel mode only?

 

[REDDODGE]

Mine did it with smarty also. I think its cold weather related

 

[timbo]

I am very convinced it is timing, and the dail to adjust timing on the edge would be perfert idea! Fooling the IAC resistence just defueled it. I was hoping it would retard the timing but it didn't seem to,as the timing clatter is easy to notice when the comp is turned on. It sounded the same no matter what resistance value i put in,but the defueling was noticeable. Right now i'm trying to think off a way to pull some timing out by fooling the ecm,because soon, i'm going to have to do it mechanically! and that means time consuming work but it's getting quicker,i can do injector lines in my sleep!

 

[lumberjack98]

question

mine seems to be temp related also but if the map was sending intermittent signals like 15psi boost 5psi boost 15psi and so on the computer would keep trying to adjust the amount of fueling and this could be why we get this jerking. any ideas?

 

[BILLVO]

Just a thought here, but with the edge drag comp problems of not turning on when below 30 degrees among others. I am wondering if there are even more problems related to the drag comp in the cold. Have you sent it in to have it tested?



What version is it? It is the version 8. 0 W/ Drag upgrade only ,that is the trouble child here.

 

[BlitzkriegSSII]

I had a problem similar to yours and it was a dirty connection on the wire that taped the fuel pump. You may want to also check that the ground is not dirty as well. I soldier where the wire taps the injection pump. I hope this helps you out.

 

[ERuhl]

This is an old thread, the timbo found the fix already

mine seems to be temp related also but if the map was sending intermittent signals like 15psi boost 5psi boost 15psi and so on the computer would keep trying to adjust the amount of fueling and this could be why we get this jerking. any ideas?

This is an outdated thread, read some of timbo's followups to this. Here is one. Skip the first section about operating temps, the culprit is too much timing. Period. The miss was eliminated by fooling the ECU via the IAT sensor (resistor in parallel or replacing the IAT altogether).

First I verified timbo's suggestion by purchasing a 1k ohm resistor (1/2 watt for the thicker leads so it plugs into the connector) for less than a dollar and bypassing the IAT sensor. The miss was gone, but cold starts were an embarrassing challenge. Recently I purchased an IAT extension harness and modified it to place a potentiometer & switch in parallel. The purpose of the extension harness was solely to avoid modifying the factory wiring harness. I placed the potentiometer and switch in series with each other, and the pair is wired in parallel with the stock IAT sensor. With the switch ON/closed the pot reduces the IAT resistance (tells the ECU the intake air is very hot so it pulls timing) and alleviates the miss. With the switch OFF/open it's the same as stock for cold starts. I didn't want to bypass the IAT altogether so the ECU will be able to verify that the intake grid heater is working. I also went with a pot over the 1k resistor this time so I can dial in the maximum timing without causing a miss.

I purchased the pot, switch, and a small project box at a local electronics shop for ~$5 total, but it looks very similar to this over the counter version.

The base timing is the root cause of the miss, the IAT fooler is just a convenient way to tweak it. In one of the recent threads someone mentioned an ongoing effort to create an electronic gizmo to go between the CPS and the ECU which will allow base timing adjustments. As far as simple fixes, this is the right way to do it IMO so hopefully this becomes available some day. The other right way involves pulling the cam which I have no interest in doing.

So again, read up on timbo's post history and say goodbye to that annoying miss!