Ok, I have the TBI 350.. I been looking for a bit more power.

Anyhow, so when playing with the timing, I noticed with the brown wire connected, instead of advancing the timing, at idle, it goes to ATDC to the right looking at the windsheild. I thought the ecu was supposed to advance timing, not retard it.

With the wire disconnected it sits right at 0 where it should be.

After i notcied this I adjusted my timing to 2* BTDC(with wire disconnnected, and forgot to hook up the wire, drove it down the road, basically with no advance, or so i assumed (because ecu isnt connected) It pinged like crazy with the wire disconnected, pulled over connected wire, ping gone. Weird

I guess what I am asking is this.

With the wire connected, shouldn't the ECU be advancing the timing? From a base of 2 degrees? If so why did re-connecting it stop the ping?

Grrp this is gettting confusing.

Wire disconnected, sits at 2* base timing.
run down the road, it pings like mad.
Hook wire back up ping is gone.

Wire connected at idle (500) the light shows the mark at about 8 ATDC (the right side looking at the windsheild.) Shouldn't it be advanced (12-8 deg BTDC) with this wire connected?

Is this all wrong? is it possible the mark is in the wrong spot, im hopelessly confused.

One last question. Hooking up a vacuum guage to constant vacuum i get 16-17"

Blipping the throttle and releasing pulls it up to 24. Staying off the throttle it drops to 18, then slwoly settles to 17-16.

At idle occasionally the idle roughs a bit, and vacuumgoes to 15, then returns to 17 where it sits.

Is this ok vacuum for this engine, only mods are Ultimate TBI mods.

More about my engine and some of the things I have diagnosed lately on this thread.

Other thread

 

Can anyone explain this for me? Kinda lost
/\ BUMP /\

 

thats definatly an odd problem. Assuming your doing all the right procedures, the timing should advance at idle, regardless of whether ping is present or not since the ecm supposedly only retards timing when the rpms are greater then 900 rpms. The ping definatly sounds like the timing is too far advanced or your mark on your balancer is incorrect if it pings with the timing bypass disconnected. With it connected, the ecm will retard the timing when it detects knock. The only things i can think of is try making sure the mark on the balancer is correct. Does it still return any codes? The 32/45 where obviously from a egr thats stuck open but the 34, which is easily set by the open egr, can also possibly signify a bad map sensor, which can cause some really screwy problems if the computer doesnt flag it.

 

never mind.

 

So if I set it to 2 degrees, BTDC, and leave the wire disconnected I should not be getting any ping? Here's what it looks like with and without the wire.

 

NM? did you have a suggestion for me? or am I totally clueless and missing something simple??

 

One more question. With the air filter and air filter container..(dont know what to call it) and the collar that goes under it removed. S

Should I be able to open the oil cap on the drivers side valve cover and see oil slapping around in there? It seemed to me to be a little dry, there's oil in there, but not visibly slapping around like I am used to seeing on foreign rigs.

I was told that the hose that connects to the valve cover and then to the throttle body collar, provides vacuum to help lift the oil to the top of the heads, I dont buy that.

Could this account for abnormally high oil pressure upon starting? It seems I have near 80lbs at start up after it warms, it drops to 60lbs but never below that, is it possibly something is clogged not allowing oil up to my lifters?

BTW still looking for answers to the timing Q

 

As long as there is oil in there your fine. There wont be oil splashing around at idle in stock engines, just oil coming out of the tops of the psuhrods. The hose that runs from the pcv in the valve cover to the tbi base is to ventilate the crank case and prevent the build up of volitile oil fumes and blow-by, which prevents sludge build up. As for the oil pressure, what kind of engine do you have in there? Some of the OE replacements have HP pumps in them which make lots of pressure.

As for the timing, you really need to get some sort of scanner or data logging system. All you see is the ecm's output and not the inputs that it is getting from the various sensors. Having a scan tool might help determine what is causing it to do that. I suppose it could also be the ign. module in the dist. but they usually jsut die, not retard the timing when they get signal from the ecm.

 

I really have no idea what engine I have in there or what has been done to it. Is there possibly a way to identify parts without having to tear it down?

I bought it used, and there's lots of extra wires, wiring harnesses pulled out as if inspected, and a few interior add ons. I think he may possibly have rebuilt the motor but I have no idea how to tell.

Unforunetaly a scan tool od aldl cable isnt in my future for at least a month.

 

Ok I, this thing is just confusing me terribly, keep in mind IM not a big time mechanic, don't even qualify as much of a shade tree mechanic.

Ok so I go out to mess with this timing thing and maybe get a clue.

This is what I did, figuring maybe my timing mark is off, and I got mad ping at 2* with the wire disconected.

So I retarded the timing (by the mark) to about 2* ATDC with the wire disconnected. I blip the throttle, and I see it advance. I thought with the wire disconnected it wouldn't advance at all, but it did.

Still under the assumption my timing mark is off, I leave the wire off and go for a drive, responds okay, but with absolutely no ping. I think im on to something here, So i pull over, and hook up the wire, doesnt seem to make a difference at all.

I get home, whip out the light(with wire connected), and it's idling about 12* BTDC, looks good. I blip the throttle, and the damned thing retards to about 4* ATDC grrph...

I guess why I am so confused is that i'm a logical guy. I have no ses lights so I assume the engine/sensors are in the good.

Now when you hit the throttle the ecu is supposed to advance the timing it's just not happennig. I guess if I had timed more 350's I'd have a clue.

What is this infamous Knock sensor. Is it possible It's bad and picking up knock, retarding the timing instead of advancing it?

If I find the knock sensor and unplug it, I know it will drop a code, but will it still retard the timing as if it's getting knock?

I'm sorry if this has been covered 1000 times, but I did a few searches, I feel I read every post on this board. I spend hours here. I think this is kind of a unique problem

 

there will be some advance, just not much without a signal from the computer. Try this... retard the base timing untill the engine idles really poorly. This will basically pull jsut about all the timing out and there should be no knock. Reconnect the bypass wire and try revving it (carefull you dont flood the engine on restart, it wont fire right away). If the timing advances, then youve pretty much found your problem. Too much base time or something else causing the engine to ping. I suspect taht every time you revv it, the computer sees knock and pulls timing out to prevent it, hence the reason you only hear knock when the timing is bypassed and see it retard with the ecm controlling the advance. The engine shouldnt run ok without the timing from the ecm, it should run like pure **** since there is almost no advace at all from the module. I suspect that for what ever reason your just giving it too much base timing.

 

Ill give that a shot. retard timing until it cant take anymore. Rev engine.. if I get advance, then timing mark is off.

If it still pulls out timing, check knock sensor.

I really appreciate your help. Thanks a lot.

I don't have anyone around here to help me out. All the gearheads(friends) that are in my neighborhood say "Take out all the electric crap and throw a carb and good distributor on there, thats all you need.

I refuse. I have a system perfectly capable of runnning great with better fuel efficiency, i jutst need to fin oout whas wrong with it hehe

did I mention I really appreciate your help. Thanks a lot. :hail: I have also learned a lot from your previous post all over this board, im sure others appreciate it as well

 

It sounds like either the pickup coil wires are reversed going to the ignition module; or the ignition module or pickup coil is bad.

With the bypass open the timing should hold rock steady until about 1600 RPM. At that point the timing should suddenly advance 12 to 14 deg. As the RPM returns to idle that advance should back out to where the base timing is.

RBob.