84, nothing aftermarket but ann 85 fuel pump, air pump delete.
When I first bought the car a month or so ago, I had a tough time with a dirty fuel system, I've basically replaced everything but the lines and the tank so far. It will run great when first started. No problems, but eventually it gets warmed up and 1) doesn't want to idle, gets down to 700 and starts surging until it dies, causing you to have to two foot it at red lights, and 2) the knock sensor starts retarding the timing at lower and lower rpms the longer you drive, until it gets to the point where anything over 2500 rpm and it bogs out. When you first crank it in the morning when it's cold, it idles like 1500 1700 rpm and runs great. When the knock sensor starts kicking in, it is idling around 700. Not sure if the two are related. I can shut the car off and sit for 2 minutes, crank it up and it runs good again for a little while, but eventually the knock sensor starts again.
I've only ever had the one 43 code... but now, even with these problem, I have no code at all.
I do not have the regulator fitting to check fuel pressure, I ordered a rail with a gauge in it for the throttle bodies, hasn't arrived yet and I'm scared to drill holes in the regulator.
Is this a symptom of losing fuel pressure? Is that the regulators?
I know I don't have enough fuel pressure info, but was hoping someone may have experienced similar problems.

 

The fuel regulator maintains line pressure.. you cannot see your pressure untill you install your rail kit adapter.. how is the spray pattern on the TB injectors?? Are they original injectors? How old is the 85 fuel pump upgrade.. fuel pumps can get weak... and not supply enough fuel volume..

 

jeremy; can't help you much on your problem. i see you did a air pump delete.

my air pump was loose and on further inspection, found the bottom bracket had a tab broken off.

is there any chance you saved yours and might wish to sell it.

thanks gary

 

injectors are new, spray pattern looks great. the 85 fuel pump is about a month old, it was put in while the tank was really dirty though. I actually took it out, cleaned it and replaced the strainer after about 2 weeks.

 

Are you talking about the aluminum looking triangle bracket? one bolt going straight down into the water pump area? I believe I do still have it, I'll dig through the scrap pile for ya.

 

yes thats the one. some one changed the water pump and put the wrong one (water pump) on this car.

it didn't have the mounting hole and casting for that bracket. they left it loose and the strain on the other mounting point was to much and it broke.

one thing i can tell you about my car. likely the same owner changed the starter. it looks like when they did, they broke the top off the knock sensor.

i have been working on getting this car running and addressing the biggest issues first.

mine to didn't have a any code so i wasn't to worried about it as it ran kinda ok. when i did get the sensor changed out-DIFFERENT CAR- took care of some drivability problems and stopping at intersections and having to do a toe dance no the foot feed to keep it running. the knock sensor i put in was a ac delco 213-325 or gm#10456287

not sure why wouldn't throw a code and not sure how to test sensor. as i said mine was broken so i knew it was bad.

the other thing my car needed was a TPS. this had a code though. so i changed it and that would let me drive it.

 

When I bought this one, same thing, it was broken, wires hanging loose, the shop supposedly rewired and replaced it, but they screwed me on everything else so probably got me on that too.

I do have the piece still, I am in Central FL.

 

will get you a pm tis evening or tomorrow
have to get to work 15 min ago

 

I had a similar problem on my 84 and i also got NO CODE after i replaced my knock sensor and knock spark control module both ac/delco parts on the firewall near the pass tire.

Sadly it made my car run like crap idle like crap smoke like crap and eventually shut off and not want to re start.

Left in the new knock sensor torqued to 14 foot pounds, and just disconnected the blue wire from the knock sensor to the module.

Still have to test my grounds etc per the FSM, to find out what exactly what was causing it. So i don't have an exact solution yet.

Re-checked my base/static timing set to 6 degrees and it's running good now.

 

had a similar problem with a TBI vehicle, it was injectors and ECM

EGR passages in intake were plugged solid, too.

Ran flawlessly for almost 10 yrs after that

 

So on the way home, just to try to pin down the problem more, I drove until it started doing it, then I pulled over shut it off and immediately cranked it again. It ran great another 5 minutes until it did it again. So it's got to be dropping fuel pressure. This is probably stupid but... The rim of the sending unit is only sealed for weather right? I mean, if that isn't perfectly sealed it won't have anything to do with the fuel pressure will it?
I ordered a regulator diaphram kit, if that's not the problem at least I'll have a spare.

Also, my fuel economy has went down considerably and my gas seems to be going a lot quicker, quicker than the economy would justify. I am starting to think I have a leak somewhere.

 

one thing i should have mentioned. when i change my knock sensor my base timing changed to 6 degrees AFTER tdc. reset to 8* before. now the idle timing goes to almost 30* before tdc.

does sound like you have more a fuel problem.

so if there is a lesson here. it is fuel problems and knock sensor problems might not or don't set codes???

 

Is that the module attached to the bracket on the fan behind the passenger tire? I did have a pink/white stripe wire and black wire that was cut running to that module on the big can fan under where the AC lines run into the car. But I could have sworn my AC fan blew harder after so I figured it had nothing to do with it.

 

Yes, double check that your wires are not cut or corroded, and that you have a good ground.

Follow the fsm procedure for checking that it works.

I don't have a timing light that checks advance which is why i didn't do it right away.

I still have not done this to ensure my wiring is good so that may be the problem in my case.

I found in my case 89 octane gas was better than 87, NOT to start an octane/performance debate, just saying in my case it's worked better for me. NO scientific basis, NO hard evidence JUST my observation in my car.

 

What makes you think the knock sensor is retarding the timing causing all your problems? I would start with the fsm and approach this systematically.

 

What else has the ability to retard the timing? It isn't off all the time, only after driving a little while, then I can kill it and immediately restart it and it runs fine for a little while again. It's a pretty unique feel when the knock sensor retards the timing, it's like a rev limiter that's set way to low, it may not be but I can't imagine what else could do that.
I do need an FSM though, in a quest to get these parts at the lowest price, I may have screwed myself, haven't even gotten a tracking number on my rail yet. Maybe they build per order.
EDIT: I also need the equipment to get data logs, all the code pulling I've done is with the splicer wire technique.

 

How in the world can you tell by seat of the pants that your timing is being retarded as you drive? Are you monitoring the parameters with a scanner as you drive? How do you know the lack of power isn't from a fuel delivery issue? Maybe you have a bad ignition module. Again, I would approach this problem systematically intead of assuming the problem is from retarded timing with no real basis. I would start by doing a complete tuneup. Cap, rotor, wires, plugs. Then check the fuel pressure as you drive. See if the retarded feeling is fuel related. Buy or borrow a scanner and watch the ignition timing as you drive. Then start throwing parts at it. Good luck.

 

What if you actually have a engine problem that is causing knock which the KS is observing and correctly retarding the timing ?

There would be no code because the the KS is working as it should.
You only get a code 43 when there is a fault with the KS circuitry ; not when it reacts to knocks or the engine actually had knock

Edit
But as 383vett states ;
without datalogging you are just taking a punt on what you THINK is the problem and possibly wasting time and $$$ chasing the wrong problem