Many Problems - Can't log

[donkeylips]

So you get what you pay for when you build a winter beater from spare parts. The car is mostly stock, but it's running quite rich since I only had a 255 fuel pump and stock FPR lying around.

I drive this car 43+ miles every day and lately, when I'm about to reach my destination, it will start stumbling, stalling etc. Sometimes violently; and it feels almost like some kind of fuel cut. This usually only lasts for about a minute, then it goes back to normal. It drives and boosts normal, aside from some bad idle surge because my throttle body is a POS and my ISC isn't connected. Base timing has been set properly.

I've had two CEL codes for a while - coolant temp sensor (which I can't for the life of me figure out; resistance of wiring has been checked, various sensors have been checked and tried, as well as a couple of different ECUs) and crank angle sensor.

Another weird thing it's doing - the stock boost gauge usually doesn't work . But sometimes it does(often when I first start it up and drive for a quarter mile), and when it does, the chances of stalling/stumbling increase. Also, the CEL didn't come on today until after I'd been driving for a minute. Usually it comes on within seconds.

First question:
What might be causing this problem? The only things I can immediately think of are:
1)Messed up wiring/loose connections
2)Bad CAS
2)Something fuel related. It sometimes leaks from the sending unit. Too many broken studs, and RTV only seems to work for so long.


So I decided to datalog with a laptop using my brother's DSMlink V2 cable (the one with the separate power wire). I'm pretty sure I don't need a null modem adapter for this. I put the power wire on a side of a fuse slot that had 12V. I have logged with this laptop before (it has a serial port and is running TMO Logger in Windows 98), but not this cable. When I click "connect", 1 out of 4 times it will say that the logger is working properly. Other times it says that it isn't connected. When I get to the actually logging screen, it doesn't collect any data.

I also noticed that when I hook up my radioshack 12V buzzer to the diagnostic port to hear the CEL codes, it is very very faint and I can barely hear it. On my other cars, the buzzer will sound much louder.

Second question:
Why can't I datalog?

 

[donkeylips]

I think I fixed it for the most part. It was my fault. My MPI Relay are just hanging (not bolted down), so I used jumper cables to ground them for now. 98% of the time the CEL is gone and the boost gauge works properly. but once in a while the boost gauge stops working and the CEL comes back on briefly. I'm going to try logging again one of these days and see if it works.

 

[donkeylips]

So that didn't really solve the problem. But it was no coincidence since I've been driving it for months and I had a few days of CEL-free driving for the first time. On Monday I did over 50 miles of mixed driving without a CEL or a single hiccup. But Monday and Tuesday the CEL kept turning on and off. The car was hesitating and stalling worse than ever. The entire way to work and back...both days.

But strangely, the CEL was on all day today. But I had no problems. It seemed to be misfiring a lot at idle, but for the whole drive it was smooth.

I must have some kind of loose connection. Next time the CEL is off (if there is a next time) I will try to log again and see if I learn anything.

 

[donkeylips]

Still running rich and misfiring at idle. But otherwise driving smoothly. Boost gauge is not working and the CEL is on. Now that the weather is getting warmer I'll have to figure it out.