Rotational play (Lash is around 1/32 to 1/16). The vertical play in the rotor is approximately 1.5 mm). I also get pretty consistent timing readings at idle of around 19-21 degrees.

 

is that much Rotational play normal? i would guess it is a lot, but i do not have the factory specs to check against. also, would that vertical play in your rotor that measures appx 1.5mm also equate to .055 -.060 thousands of an inch of play? mine is about .060 vertical play. the other thing is my idle timing dances around all over the place by like 30 degrees which is alot and it also has a minus sign in front of the number. i used an auto x-ray ez link scan tool. just curious, is it true you have to disconnect a tan wire with black stripe on it under the glove box somewhere before checking your idle timing? thanks

 

Yes, 1.5 mm is equal to 0.060 in. Sorry I was mixing English and Metric in my last response. I have not been able to find a spec for the rotational lash. In terms of a wire in teh glove box, I am not certain. I have a 1997 and am using a Tech 2 scan tool and don't have to do anything to get the timing value on the scan tool to read. I do believe however that the scan tool displays what is being commanded.

I have no gear wear on my distributor and doubt that there is any wear on the mating gear so I believe it is quite normal.

 

i replaced my distributor gear even though the old gear still looked OK. the truck did run a little bit better but it was a minimal change. im considering tighting the vertical movement on dist. from .060 to maybe .025 to see what it does. i also found my spider leaking some fuel in the intake today...
who makes this Tech 2 scan tool that you have? is that the brand? id like to find someone with it to scan my timing.

Have you checked your spider for leaks? also waht was your compression after lapping the valves? and does it still leak air in the intake after lapping?

 

After lapping the valves, came up to about 160 psi. Was as low as 90 psi. Still not quite as high as bank 2.

Spider does not seem to be leaking. I had pulled out the individual injector and ran a balance test as well, but couldn't tell the difference visually. Same Pressure drop on each injector.

The Tech 2 is the scanner tool that is used by GM dealers. I have access to one through a friend.

I didn't recheck the leak into the intake, but the width of the seal on the intake valves was at least 2 mm's, so I don't think it is leaking through there any more.

 

If your spider was leaking fuel into the intake then that is a huge problem that you need to address before playing with anything else.
Usually the leak will be coming from the fuel pressure regulator.
Dumping raw gas into the intake will certainly make your truck run like crap no matter what else may or may not be wrong with it.

Your truck running extra rich due to the extra fuel from the leak will also tend to kill your O2 sensors causing further problems.

 

i have a 95 S10 with some small puddling in the intake. just curious, how would that puddled fuel get into your cylinders? like how would it travel there? and is it true there is a hole in the lower intake that can let the fuel fall into the crankcase? if so, would it be a good idea to close the hole off with some machinist expoxy?

 

Just finished swapping out the Spider with a new MFI conversion. Although it tends to accelerate smoother, still missing like crazy at idle. For the most part, only on clyinder #5. Will set a P035 code as well. If I drive around, will only pick up misfire when at 0 throttle and low vehicle speeds, and at idle.

Went back and tried putting old cap and rotor back on. Different wires from other cylinders, moving plugs. No Luck. Fire it up and it misses like crazy on Cylinder 5.

What else could ther bit electrically that would cause the misfire to occur mainly on cylinder 5? I'm truely stumped.

 

The fuel would enter the cylinders the exact same way that the air needed for combustion does. And NO it is NOT a good idea to close off any holes in your crank case that have been designed into the engine. Just fix the problem that is causing your fuel puddle and be done with it.

 

What type of plugs are you running in this engine? I know that there are several non AC delco brand plugs that are known to cause misfire issues with these engines. The same goes for some brands of non AC delco distributor caps and rotors.