Help with ignition Timing

[texas tough]

if it was a fuel pressure problem it would run worse at higher rpms, not better .

 

[texas tough]

I didn't have any problems timing my '94 4.3L with that wire disconnected. It was rock steady on 0 degrees when I set it. Being a '94 and with it jumping around you might need a new distributor.

he said hes revving it up with the connector unplugged..!!!! the knock sensor is likely detecting knocks so it is trying to keep him from blowing the engine.

 

[L31MaxExpress]

if it was a fuel pressure problem it would run worse at higher rpms, not better .

Not necessarily. Pump shot fuel at low rpmrequires strong fuel volume for adequate pressure. If you don't get that quick burst of fuel on the low end it will stutter like a carb with a bad accelerator pump or even backfire into the intake. Also when you go WFO the ECM lengthens the pulse width for power enrichment. I have had marginally performing fuel systems cause a loss of power at lower engine speeds that suddenly becomes somewhat normal in PE.

 

[Lscobra]

he said hes revving it up with the connector unplugged..!!!! the knock sensor is likely detecting knocks so it is trying to keep him from blowing the engine.

Tell me how revving the engine at 0 btdc is going to blow the engine.

 

[PlayingWithTBI]

Tell me how revving the engine at 0 btdc is going to blow the engine.

Well, one thing, by disconnecting the EST bypass wire, the ECM can't change timing, it's "bypassed". So, KCs aren't an issue.

 

[Lscobra]

What are KC’s?

 

[PlayingWithTBI]

What are KC’s?

Knock Counts, sorry

 

[Lscobra]

Knock Counts, sorry

Oh ok thanks. I really dont see a reason why revving to 2500 rpms or so while setting timing has an ill effect. I wanted to see if the mark on the balancer moved through the rpm range. Thats what it feels like its doing under load. It will bog, and power fluctuates until about 3200-3400 rpms and seems normal from there until it shifts.

 

[PlayingWithTBI]

I really dont see a reason why revving to 2500 rpms or so while setting timing has an ill effect. I wanted to see if the mark on the balancer moved through the rpm range. Thats what it feels like its doing under load

That's fine but, you need to set your timing at idle, don't try to adjust it while revving it up.

 

[Lscobra]

That's fine but, you need to set your timing at idle, don't try to adjust it while revving it up.

Yeah thats not what i meant to say i was doing. I understand the confusion now. I set the timing at idle. The revved to see any change in upper rpms. It did jump up probly 10 or so degrees at like 2500 rpms by itself. Thats the part i couldnt explain being that the brown wire was disconnected.