As mentioned in the title, my truck is a '92 Two door 4x4 blazer, and she's been giving me hell from day one, but i've managed to take care of it until now.

From the beginning of these issues:

I had a massive exhaust leak, such as the pipe directly after the collector just kinda fell off. I had that welded back on as best as it could be, then I used cheapo exhaust crap to plug the hole on top where you can't fit a welder.

Drove okay for a little while. Then, it started throwing a code again. Unfortunately, I can't remember what number the code was, it was a DTC and a not a P, for some reason DTC54 sticks out in my head, and it was talking about something on the left.

I can not for the life of me figure out what the hell the code meant, but, before you say "well find out the effing code!" here's my current symptoms, in case anyone can help me out until I can get it scanned again.

I've got fuel mileage from hell, I was getting a meager 17, 20 on long trips, but now i'm getting anywhere from 10-14. And I'm a college student with a 30 mile commute, not that it's really far, i just can not afford that.

I've got this strange lope and what seems like a misfire at a constant, low throttle and RPM. (potentially unrelated, it seems.)

If I step on it at a light, or just passing on the highway, i get a pretty strong gasoline smell, that I have NO idea what is. I've got no puddles in the driveway, anyone elses driveways, which tells me it's running rich, or i really do just have a gas leak somewhere. But I can't find a leak.

I do have really bad brakes, and I like to put my foot in it some, but even babying the throttle I don't get any response for better mileage, or even my usual driving habits don't do anything to better it.

 

54 is fuel pump circuit. Try replacing the 5 dollar fuel pump relay.

The gas stink is unrelated...

Well get the code with the "paperclip method". You dont need to get it scannd. Open a paperclip or bit of wire and stick it in the top right 2 holes on your plug, you are jumping the two together, then turn on the key but dont start it. The engine light will now flash your codes. It flashes a code 3 times before doing a second code if there is one.

"rich bank 2" ring a bell? Thats the passenger side, funny rhing the FPR is located on that side.

What you want to do is search up on "CPI spider" in the forums here for more info and pictures.

Go pull the hockey puck off the top of the intake and look in that hole with a light. What side is the GOLD washed area? Passenger or driver or both? it should be black everywhere inside there, no gold at all.

Driver side means a leaky "nut kit"
Passenger side means a leaky "FPR (fuel pressure regulator)"

Both parts will run you areound 50 bucks each. If its the nut kit, it will be more work as its a bastard to remove without pulling the intake off. In that case you will need intake gaskets as well for 20bucks.

Ordering your parts from rockauto.com is the best prices.

These jobs can totally be done by yourself in am afternoon with a socket set and wrenches and torx drivers. Dont be intimidated by it, its not too bad as the instructions can be found here.

Most early 90s CPI engines are getting these problems by now as its nylon lines that have dried up and are leaking 25 years later.

You aremt getting puddles in the driveway cause the unused gas is leaking into the crankcase and mixing in the oil. Pull your dipstick, its going to be way overfull amd stink like gas.

 

Gas in the crankcase is not good. Sure some of it with evaporate but in the meantime it'll act as a barrier between the oil & what the oil is supposed to be covering/lubricating. I believe the term is "washed bearings".

 

So, I take off the entire filter housing and throttle body? Or just the air filter housing? I came from a 1990 F150... hockey puck is a new term unless you're talking about body lifts, lol

The throttle body itself is all gold, i checked that out when i checked my filter last, maybe two weeks ago.

I'm gonna pick up the FPR from the local o'reilly's as soon as I've got the extra cash, not expensive, but i just put the last of my check into the tank.

 

And now I'm curious, what exactly about that relay would make these symptoms come about if it failed? What does it control, exactly?

 

Interesting development!

I went and had it scanned, and I'm not getting 54 at all. I pulled 13 and 44. Both have to do with o2 sensor, however, three weeks ago I replaced the stock one with a Bosch sensor. And the codes referring to two sensors, to my understanding I only had one? Downstream of the collector, upstream of the cat.

I reset my ECM, checked codes to see if anything was already there on start up, only pulled code 12, system ready.

I'll update that later tonight, after I've got a few miles on the reset.

 

Sorry to keep bombing my own thread, but for some reason I still feel like the ideas about 54 make sense, even if it's not what was thrown.

 

The hockey puck is the round black thing on top under the cover that says VORTEC on it. Inside this hole you will find your injector unit.

Dont buy anything till you diagnose the leak.

Dont worry about the codes till the leak is fixed.

Code 12 is normal... However reaetting the pcm takes a while. All systems have to come ready by completing drive cycles. The codes will come back... You have a leak i bet my left nut on it.

 

I know I have a leak, I can hear it plain as day, I always have. I'm confused by the codes, they're suggesting I've got two O2 sensors, but even the parts stores tell me I've got one, and I've never found a second one. Anyone have any suggestions as to what I could use to finish plugging? quikweld high temp is the only thing i can seem to find that actually holds. Or remotely holds. The hole isn't exactly in a spot you can weld, so it's really hard to plug.

Here's the background on the exhaust. I was getting about 17-20, like I said, and then the pipe disconnected directly after the y pipe. My mileage PLUMMETED, I got it welded, but it's impossible to weld it all without disconnecting the pipes, which, is also a hell of a job on this blazer. All of my piping is basically shot, splitting in some places, etc. I'm going to use the good old soup can trick to cover some of it, but I know i can't cover it all. I kept getting 02 sensor codes, so, I didi the logical thing, replaced the o2 sensor. The code didn't throw for about a whole 2 days, then I got more codes thrown. I haven't been able to recover my mileage since. I can't even manage to plug all my exhaust leaks, but, I have ideas about that.

 

Replacing the o2 sensor cause you got a code IS NOT the logical thing. It was a waste of money actually...

What you nees to do is find out why u get a code... I would suggest the extremely rich exhaust full of fuel.

2 days is about right for getting a code as i said, the truck needs to perform drive cycles before codes get stored.

You should really do as im telling you as im starting to get irritated with your side tracking... You asked for help, and im giving you instructions here that you wont follow...

Find the fuel leak - fix the fuel leak so you sensors can perform properly - dont ni**er rig the exhaust, drop a hundred bux to have an exhaust shop fix it properly instead of spend a hundred dollars on a temp fix (soup cans and glue)... Those guys can fix that with a couple feet of pipe and 20min of time... Your fix will just fall apart again.

Dont expect a reply from me again unless you have pulled that tuning valve out to find the gold washing inside... THEN, and only then will i help you with instructions on replacing the injection parts...

Grrrr... Sorry for the rant but this is a waste of both of our time if you arent going to use my advice