I placed the paperclip into the two top right side sockets to read for any possible codes. I turned the ignition key on and got no codes.But what i did get was a fast clickety noise coming from under the plenum from what I believe is the fuel pressure regulator. Is that supposed to happen? I take the paperclip out and the noise stops.
This whole thing started because I have been trying to track down a condition that makes the engine bog down with a loss of power after a few minutes after start up. It has been getting worse lately and the chief suspect is clogged cats. But with this new noise I am not sure what is happening now.
The last thing I did was to replace the fuel pump sock filter. Does that go on a certain way?
It is so slow now I can't make it to the muffler shop to test the cats.
It's a 1989 coupe with 87,000 miles and I've replaced lots of stuff since purchase last year like the fuel filter, fuel pump,distributor cap, rotor,plug wires,etc.
Any clues?

 

It is possible your ecm is playing up and it is going into "limp home" mode. The click clacking may be the egr valve.

The limp home mode also turns the the fan on.

Is the check engine light on?

 

if you missed the correct socket you may have grounded the FP and were running the pump only...its the next pin over.

Just be sure of the 2 holes that you're jumping.

The symptoms say cats. If you can pull the o2 sensor out and start the car, the exhaust should be only 2-3 lbs pressure escaping the o2 sensor hole. Any more indicates a plugged cat.

If the ECM had any useful information the SES lite would be on constantly. There might be a code is storage but current faults would keep the SES on until cleared or corrected. Cats won;t set a code.

 

Are you sure it's not the IAC motor under TB ? That is normal when going into diagnostic mode.

Did your SES light flash when you jumped A and B with ignition on ?

 

He could be using a ford paper clip...one that came holding several service bulletins together...


seriously though...the fan should come on, SES should do the 1-2 blink. As long as the key is turned to "on" and not to start. Might be missing the contact inside the sockets port or the brass tab might be pushed back. Try a shade tree jumper...a 2" piece of wire with the end stripped. Fat enough to fill the hole.

 

Make sure you're in the right pins, on my car the flange is 'upside down' from what I'd expect. Make sure you view it from the open end and short A and B as per this picture..

Your check engine light will then flash at least 1...2, 1..2, 1..2, anything more than that 12 and you have codes..

 

The paperclip goes into the A and B slots. The SES light goes 1-2 and repeats. I can't believe the EGR valve is clicking if there is no electrical connection to it and the engine is off. The ECM is new. No fans are on. The SES light goes out when it should. The clickety sound goes away when I remove the paperclip. Agent 86 says maybe it's the IAC motor under the TB. What's that and what does it do?
Is there an electrical connection to the fuel pressure regulator that I can't see, like under it? Is the only function of the FPR to redistribute the fuel back into the tank when not needed like when the car slows down or does it also increase pressure (and also volume) when the throttle is depressed like when calling for acceleration?
My major issue is that the car bogs down when I try to accelerate as if it's starved for fuel. (Clogged cats would also show those symptoms). That's why I changed the fuel pump and the sock filter recently. I replaced the injectors and the fuel filter last year when I first got the car. It ran well then.

 

EGR won't click period, driven by vacuum only. FPR might make some sounds but normally none (and no there is no electrical to it).

IAC will make a clicking sound, very rythmic, its a stepper motor, but should only do so for a few seconds. On the side of your throttle body, opens and closes to allow specific amounts of air to maintain idle and as an anti stall on decel..

Does it hesitate or actually continually bog? If hesitation then goes, usually the TPS (throttle position sensor) is shot or mis-adjusted. If it bogs all the way through throttle, then many things can cause that but most should eventually through a code via the O2 sensors (if it goes too lean they should complain)

Continous bog = plugged exhaust, low fuel pressure, mis-adjusted timing, plugged air filter, low compression, cam timing off (seldom happens since the 70's), bad MAP sensor or plugged or leaking vacuum line to it..

If it flutters and misses while bogging, bad plugs, bad plugs wires, bad injectors (or wiring to them), bad seal on intake or exhaust valves etc etc..

Many of the above will have very hard to notice effects on idle, others no effect at all.

Try to describe better the bog itself, does it clear eventually, does it only happen past a certain RPM, or only past a certain throttle position etc..

 

Maybe it would be better to explain my normal driving habits in relation to the car's behavior.Normally I accelerate with economy in mind, that is with the six speed manual I take off just fast enough to get into second but faster than it would go into fourth if it had a mind of its own. I change gears at about 2,000 to 2,300 rpm not going fast or too slow.But sometimes my speed calls for a little more oomph, like 2,500 to 3,000 rpm, like accelerating onto a freeway from an on ramp or going around some slowpoke.Normal but spirited driving you might describe it.
Lately I am not getting that oomph when I step on it a little. It used to bog down at around 2,300 rpm. Push a little harder and no smooth response at that rpm. Something is holding it back. It's smooth but sluggish. So I changed some little things to counter that lack of oomph like make sure the timing is right, new air filter,new fuel pump and pump sock filter.Nothing has made a difference. Actually the last thing I replaced, the sock filter actually made it worse,(maybe a coincidence?) so much so that my speed is so slow now that I am hesitant to actually drive it to the muffler shop to have the cats tested. Although I had good fuel pressure last summer when I changed the injectors I can't rule that out but it does have a new pump.
That's why I am trying to determine if it is indeed the cats or should I be looking elsewhere. So, I was surprised when I heard the clickety clack when I did the paperclip thing. That sound seems to be coming from the area near the FPR and goes away when I pull the paperclip.
It remains a mystery.
My problem could be something as small as a pinched piece of rubber or something like that or it could indeed be clogged cats. I drove it almost every day this last year, about 5,000 miles. It has 87,000 miles on the odo right now.

 

This is the sound I get when I use the paperclip in A and B slots to look for codes with the key on. The sound stops when I remove the paperclip. What is it? It seems to be coming from the area around the EGR valve either in front or to the rear of it. Anyone have this happen?



click on the photo to hear the noise.

 

Have never heard anything like that under hood at anytime; in diagnostic mode or not.
Sounds like a battery air compressor running

 

To me it sounds like a very fast injector click , have you tried touching them to see if one is clicking

 

 

EGR solenoid most likely. No vac to hold it so its bouncing back & forth.
Unplug the solenoid then see if the noise stops. If not then do the fuel relay or fuel fuse.
Unplug things 1 at a time until the click is found. I'd be more interested in the codes myself. If the ECM is not showing thr SES lite, then searching for codes is pointless.

Plugged cats is easy enough to test. Pull the o2 sensor and see if there is pressure there. FSM says more than 1-2 lbs pressure out the hole means plugged cats.

 

Not to hijack your thread but I'm getting a 1...2 1...2 1...2 then 12345 what is that code? 92 lt1

 

Although the EGR solenoid is under the TB bracket area. I thought it was it till he went to the passenger side and it sounded a whole lot louder.

The only things in there that I can think of making noise.
Injectors
Fuel reg
AIC motor
egr solenoid.

I would think just putting a finger on it would indicate the problem.

as far as the cats being clogged. I had it happen. you are not going to get a code. if felt like someone put a potato in the tail pipes. I could only get to 2K rpms and drive home at 35mph in 6th.

 

1...2 is code 12. which means it is doing it's thing. it will repeat each code 3 times.

12345 makes no sense.

you should get a code between 13-99.
2 digits only.

it would appear you got code 12 34 and a 5 or 1 23 45. Makes no sense.

But the real issue is, the codes will repeat 3 times. 12345 is not repeating.

Maybe it will count up to 10 one day and then blow up?

 

what i ment was after the 1...2 3 times it will flash ck enging light 5 times in a row with no break

 

And then what does it do?
Here, check these 2 pages out. Probably explains it better then I can without typing all of that out.

http://www.corvettephotographs.com/c4vettes/codes.htm

http://chevythunder.com/199295_lt1_trouble_codes.htm

The five blinks would seem like you are ready to get a 50 something code... I am guessing you are not waiting on it to get the next part? or is it code 55? I have no idea how it will flash out a code 50. Seems to me there should never be a code 0.

Hope these 2 pages will explain what you are looking for.

Is your check egnine light even on indicating there is an issue?

 

If I recall correctly, the main cooling fan should turn on in the diagnostic mode. The OP says that it did not. Could this clicking be from the fan relay? Does the fan operate normally?