help with chevy truck

[Jim Woods]

I have a very nice 1995 tahoe and I started having problems upon acceleration. I changed plugs, wires, rotor and cap also fuel filter, no help. the local garage said o2 sensor, no helpI changed fuel pump, fuel reg in TB and TPS sensor, still no help, egr valve and spark controller in distributor. no help, today i changed timing gears and chain, started up but when I went to unplug wire to set timing the engine stops . I 'm lost can anyone help?

[Ed Wright]

Originally Posted by Jim Woods

I have a very nice 1995 tahoe and I started having problems upon acceleration. I changed plugs, wires, rotor and cap also fuel filter, no help. the local garage said o2 sensor, no helpI changed fuel pump, fuel reg in TB and TPS sensor, still no help, egr valve and spark controller in distributor. no help, today i changed timing gears and chain, started up but when I went to unplug wire to set timing the engine stops . I 'm lost can anyone help?

Jim, check the shaft in the distributor for weak magnets. To do that just hook up your timing light, unplug that tan wire, and fire it up. Someone may have to sit inside and keep it runing for you. At idle the timing should be at Zero (TDC), rev it up to 2500 RPM. By 2500 the timing should jump up ten degrees. Won't be gradual, it will jump. If it does not advance, or even retards slightly, you need a new shaft in the dist. Don't go to Autozone,O'Reiley's, etc, for a reman distributor. Go to the GM dealer to buy a shaft, and pray it is still available. I used to keep three or four of those things on the shelf. Also causes stalling at idle when shifted into Drive, or Reverse. Most did it worse going into Reverse, but don't ask me why. Watch the dimple in the gear, it is supposed to align with the rotor blade. Knock the pin out, pull the gear, turn the distributor upside down and spray Berryman's Chemtool B12 down inside the housing, around the shaft. Let it sit a while and the shaft should slide out. Going to make a mess, so don't do it anyplace clean. Knock the shaft out and you will usually break the distributor housing.
Good luck, Ed

[doug schriener]

Jim-One thing ya might see with the magnets on the dist. shaft if ya look close ya could see cracks-they can disrupt the signal trying to be generated and can cause a couple different things to happen.While you're there maybe change the pickup coil.Lotsa reman motor guys won't warrantee their stuff if ya don't change that dist. shaft 'cause it can make for real weird timing fluctuations and raising hell in the cylinder.

[Jim Woods]

Ed , when I unplug the tan wire , the engine stops.

[Jim Woods]

Doug , I will check for cracks

[Jamie Greening]

Check the timing with it hooked up. Should be some where around 14 to 20 depending on calibration. If not unplug knock sensor. I've chased my tail so much because of a bad knock sensor shorted out. Does it have a lot of miles?

[Ed Wright]

Originally Posted by Jim Woods

Ed , when I unplug the tan wire , the engine stops.

They usually stop when the tan wire is unplugged because the timing is too slow. A second person working the throttle can usually keep it running in that case.
Hope by Holley you don't mean you put a Holley throttle body on it. :-(

[5798camaro]

try unpluging your mass air flow sensor

[Tod Lane]

I too hyave a 95 Chevy truck with about 200,000 miles on it. Would this dist shaft problem cause low HP/Sluggish performance and lowered fuel mileage?

No missfire I can hear, you do have to pump it a couple times to start it.

Recent plugs wires and cap, maybe 15,000 miles

The truck burns no oil, compression is good in all eight Cyls. It almost feels like the Cat Con is plugged.

[doug schriener]

Originally Posted by Tod Lane

I too hyave a 95 Chevy truck with about 200,000 miles on it. Would this dist shaft problem cause low HP/Sluggish performance and lowered fuel mileage?

No missfire I can hear, you do have to pump it a couple times to start it.

Recent plugs wires and cap, maybe 15,000 miles

The truck burns no oil, compression is good in all eight Cyls. It almost feels like the Cat Con is plugged.

Tod-Have you checked the timing per the advice on this thread? Be certain that you're getting your full ignition advance-we all know how doggy that can feel-if you have never replaced the shaft in the dist. I would just in the interest of good maintenance.The timing tag under the hood will give advice on checking timing also so you should have lotsa help there-good luck. Doug Schriener