Temporary Fix for Random Misfire

[b4christ15]

Like most 6 bolt powered 2g's, my 95 is having the dreaded Random Misfire . I plan on getting myself a DSMLink but my funds are short right now so I'm looking for a temporary fix until I can afford one. I've heard of the 10k POT fix and unplugging the TPS. As far as the POT mod, I've heard mixed reviews so I'm gonna stay away from it for now. I want to try unplugging the TPS and see how that goes but I'm not sure of where its located on a 92 6 bolt. If anyone with pictures of where its located and any other things involved with its unplugging can give me some help I greatly appreciate it. All other info and help with this problem is welcomed Thanx a bunch to all - Blaine

 

[95blackGsTurbo]

The TPS is located on the side of the throttle body. Not to hard to find. But that won't fix anything. Then your car won't see any voltage from it and won't adjust the fuel trims properly and you will do more damage then if you just left it plugged in.

 

[b4christ15]

Thanks for the advice. I'm gonna unplug it and just give it a shot and see how she runs. If I notice more harm than good, than I'll plug it back in and deal with it.

 

[blackGSX2g]

Its likely that you will not 'feel' a noticable difference in removing the TPS, but if you were to watch the logs of your ECU, the difference would be noticable.

By chance are you using the 93/94 black top CAS? Those are reported to have the least amount of cases of the random misfire. I've got the black top on my car and haven't had any problems after about a year of having the swap. Every month or so it will throw the code, but the misfire stops as soon as I clear the light and let the motor come back down to idle.

If it bugs you that much, you can try the POT mod but be very careful as it will lean out your mixture.

 

[b4christ15]

I believe my CAS is from a 92, its the green one. I want to get a datalogger so I can keep track of things and clear codes. Will this aid in getting rid of the RM? I want to try and stay away from the POT mod if I can.

 

[blackGSX2g]

I believe my CAS is from a 92, its the green one. I want to get a datalogger so I can keep track of things and clear codes. Will this aid in getting rid of the RM? I want to try and stay away from the POT mod if I can.

I agree with wanting to stay away from the POT mod. The black top (hall affect) CAS produces a signal the more closely mimics that of the stock 95-96 sensor compared to the green ones (optical type).

Here is a link to the waveforms of the different sensors:

http://www.roadraceengineering.com/1gcasin2g-waveforms.htm

It is by no means a perfect fix, but it appears that people have more luck with the black top sensors.

 

[b4christ15]

So would it be possible to swap my green CAS for the black top one and possibly solve the RM?

 

[blackGSX2g]

I can't guarantee results as I think it really depends on the car, but I can say from expience that the 2 cars around here that have the swap both have black top sensors and have no RM. The one I knew with a green top has the RM issue quite often. If you can find a sensor for cheap, just swap them out and plug your existing harness into it and see. Also make sure all of your harness lines are cleanly soldered and connected to rule out any other sources of misfire.

 

[Syndicate13]

It's really hit or miss with the black top CAS, I have one and can't drive more than a few miles without RMing. If you want DSMlink, do it and never look back. The ECU does not reference the TPS to adjust fuel, at least not under load. You will have idle trouble though as the 2G idle switch is incorporated into the TPS.

 

[b4christ15]

Trust me, DSMLink is the next thing on my list as soon as I have the funds. I'm just looking for a temporary fix until that time comes. As far as the TPS is concernced, is there any other problems besides a rough idle when it is disconnected?

 

[1993eclipseGS]

I disconnected the TPS sensor and haven't had a random misfire since then.. Although it may not be the correct way to fix the problem, It has worked for me.

 

[b4christ15]

I disconnected the TPS sensor and haven't had a random misfire since then.. Although it may not be the correct way to fix the problem, It has worked for me.

Have you noticed any driveability problems since then? I've heard rough idle and bad gas mileage are results from disconnecting the TPS.

 

[1993eclipseGS]

It actually ran better. Before I disconnected the tps, I was getting random misfires constantly, Every day. As soon as I unplugged it, All was well.

 

[b4christ15]

Well, I unplugged the TPS this past Friday and the car hasn't seen any misfires since. Everything seems to be going smoothly. Idle is fine and gas mileage seems to be what it was before. Hopefully this will last until I can get me a DSMLink . Thanx for the help.

Blaine

 

[marq95gst]

I am going to try this. Will post tomorrow if it worked or not.

Thanks~!

 

[marq95gst]

Thanks. I will try this too.

 

[Turbo Talon 111]

the black top sensor will definately give a better chance of not having a random misfire. there is another trick to get rid of it though if that and the other tricks don't work. Using a '97+ ECU should remedy the problem. Those ECUs are used to having CAS. You may need to use a '97+ CAS also but i'm not sure about that part. just don't get rid of your '95 ECU if you plan on using DSM Link. If not then you can sell it and make a bit of money.

 

[marq95gst]

Thanks. I will try this too.

Tried it. Didn't help. But then everyones car is diff. Swapped the ecu, still does it and on the same first two cylinders. It has to be in the wiring (ground). ahhhhhh!!!!!!!!!!!!!!!!

 

[T5Kthrasher]

Any one hear of a 7bolt in a 95 having random misfires?
Who ever worked on my car before me really did some weird stuff. I have a 7bolt motor with a cas (black i think) and a 1st gen coil pack.

I was getting random misfires around 3k and it would make the car lose all power for a few seconds (major stuttering).

I pulled the TPS and the code will still pop up and no more stuttering (much nicer to drive)WTF

 

[phillabaum03]

I just got done with a 6 bolt swap and it was misfiring around 2000-2500rpm. Pulled the TPS and no more spuddering.

 

[turbo16]

I tried the same thing to and pulled the TPS right out and after 3 months of having my car not running it finally ran like the car should run very happy so far with this method!

 

[EnticivEclipse]

anyone got a pic of exactly where the TPS is

thanks

 

[titogs95]

anyone got a pic of exactly where the TPS is

thanks

From DSM Engine Primer!

Picture 1

Picture 2

IF you can't afford Dsmlink you can always install a custom chip. DSMCHIPS

8. Cam/CAS Inversion - This feature is necessary when using the 1995 ECU on a 1997+ car, or if you have done a 6-bolt swap. The 97+ and 1G sensors put out an inverted CAS signal, which changes the injector firing order. This CAS Inversion fixes the injector issue, but you still need to swap plug wires 1&2, and 3&4 if you have a 1997+ car, or have done a 1G 6-bolt swap.