85 60 full desmog, sniper, & tuned headers - questions and progress (4 Viewers)

[brownjeans]

I’d recommend verifying the timing with a timing light. You should be able to rent one from a local auto parts store.

Not exactly sure how to do that. I think clip the light on the wire to the first piston, then shine the light at the window on the flywheel and ensure the light flashes at the same time as when the bb is below the indicator - is that right?

 

[DrRock]

Not exactly sure how to do that. I think clip the light on the wire to the first piston, then shine the light at the window on the flywheel and ensure the light flashes at the same time as when the bb is below the indicator - is that right?

Yes, exactly. Timing light will have clips to connect to the battery and a clip to go around spark plug wire #1. Keep the settings on the light stock with no advance if it has those features

 

[Skreddy]

Okay. I got some carb cleaner, sprayed all around the sniper base, under the stock heat shield thing, on top of where the manifold meets the head, below where the manifold meets the head, where the block-off plate is and where all the things screw into the top of the manifold. Nothing changed. I think things are sealed pretty good.

So on to the sniper screw. After many cycles of asjusting the screw, turning the truck off and back on again ("have you tried turning it off and back on again?" - this is what we get for introducing a computer into things I guess). Here are my readings:
View attachment 4007124
That MAP still seems lower than the 80 ish. When I start it, the IAC Pos, % starts at around 30, then settles to here. The AFR, A/F moves .5 above and below 14 (what is in the screen shot is me catching it at the high end). I retested the vacuum pressure on the manifold, it is now holding at 17 at 4300 feet elevation. The only hiccup I have is that when I press the accelerator and then lift, the AFR, A/F spikes super lean for a sec - the truck acts like it might stall, but then it recovers.

I also went through the setup wizzard again to re-set things. What do we think? Are there other things I should check or is it time to drive and let it learn?

I just checked and my MAP is at 40 at idle at about 2500’. Conversion chart I was looking at must not have been correct. So I’d assume you’re good.

 

[brownjeans]

My throttle pedal sits really high now - like as high as my brake pedal. I think I need to do something about that. Anyone else have their throttle pedal be weird like this after taking it off and putting it back on again? Did I lose a part or re-install it incorrectly?

It doesn't run great when cold. Stalls a lot. Any suggestions?

 

[Skreddy]

My throttle pedal sits really high now - like as high as my brake pedal. I think I need to do something about that. Anyone else have their throttle pedal be weird like this after taking it off and putting it back on again? Did I lose a part or re-install it incorrectly?

It doesn't run great when cold. Stalls a lot. Any suggestions?

Cold as in below 160 degree coolant temp? The sniper won’t start snipering until 160. Up to that point, if you need to drive it before it’s that warm, avoid suddenly going to neutral at idle if that makes sense (driving along, downshift when coming to stops instead of neutral and coast). There’s some tuning you can do with coolant enrichment, IAC bleed times, etc that can make it better. I would let it learn for a couple hundred miles, then tune for best hot starting, then tweak for good cold starting and it should get you there.

 

[brownjeans]

Cold as in below 160 degree coolant temp? The sniper won’t start snipering until 160. Up to that point, if you need to drive it before it’s that warm, avoid suddenly going to neutral at idle if that makes sense (driving along, downshift when coming to stops instead of neutral and coast). There’s some tuning you can do with coolant enrichment, IAC bleed times, etc that can make it better. I would let it learn for a couple hundred miles, then tune for best hot starting, then tweak for good cold starting and it should get you there.

Yes, engine below 160*. Start engine, start driving - in that scenario it wants to stall until it gets up to temp. If I had a choke still, I'd pull it one click and it would be fine. We'll revisit after the learning is more mature.
In the meantime I'll get the throttle pedal positioned closer to the floor.

 

[DrRock]

Cold as in below 160 degree coolant temp? The sniper won’t start snipering until 160. Up to that point, if you need to drive it before it’s that warm, avoid suddenly going to neutral at idle if that makes sense (driving along, downshift when coming to stops instead of neutral and coast). There’s some tuning you can do with coolant enrichment, IAC bleed times, etc that can make it better. I would let it learn for a couple hundred miles, then tune for best hot starting, then tweak for good cold starting and it should get you there.

This^^ Mine had some initial <160F idling issues but once I had some more miles, the learning took care of most of that.

 

[Rustyj41]

Where are you located? Also one of those Amazon smoke machines cost about $30 and it saved my life trying to find vacuum leaks.

 

[brownjeans]

Where are you located? Also one of those Amazon smoke machines cost about $30 and it saved my life trying to find vacuum leaks.

Bountiful, UT. I think I'm free of vacuum leaks. I soaked everything really good with carb cleaner/starter fluid and there was no change. Once I had the idle screw adjusted my vacuum now holds at 17.

 

[Rustyj41]

Bountiful, UT. I think I'm free of vacuum leaks. I soaked everything really good with carb cleaner/starter fluid and there was no change. Once I had the idle screw adjusted my vacuum now holds at 17.

Another minor issue I had was a plugged charcoal canister which cause a vacuum in my tank putting strain on the fuel pump. That caused my idle to sky rocket as it tried to self adjust for lack of fuel pressure.

 

[brownjeans]

Another minor issue I had was a plugged charcoal canister which cause a vacuum in my tank putting strain on the fuel pump. That caused my idle to sky rocket as it tried to self adjust for lack of fuel pressure.

Yeah, I replaced my canister and PCV valve because I was worried about potential issues. Actually, I replaced a LOT of things: All radiator, oil cooler, and heater hoses (except for the two beneath the truck under the passenger seat for the rear heater because they looked good and are easy to access later if I want), thermostat & gaskets, vacuum lines, all rubber and hard lines in and out of the gas tank. Adjusted the valves, new valve cover gasket, etc. etc.

Engine is running great now when temp is over 160*
Only trouble is when the temp is below that and my gas pedal is awkwardly high and has too much travel (because it's so damned high).