1998 Astro starting

DKORNGUTH

MEMBER
1998 CHEVROLET TRUCK

I have a 1998 Chevy Astro, 2wd, 217,000 miles, 4.3L. I recently replaced the intake manifold gaskets which requires the removal of many of the sensors distributor etc. After I put everything back together it started fine (took a couple of minutes) and ran smooth ( no leaks!). However it became increasinly hard to start, once it is runing it is smooth. When trying to start it pops and sputters like a bad cylinder or timing issue. I replaced cap, rotor and plugs but not wires yet. Could a bad wire cause this or do I need to dig deeper.

Dave.

1 Reply

ASTRO

MEMBER
12 POSTS

Take a look at my posts https://www.2carpros.com/forum/2000-chevy-astro-43l-csfi-vin-w-vt31896.html

When I replaced my intake gasket I had trouble starting. Once it was started I thought I was running smoothe too. What was really happening in my case, was that the computer was compensating for some misfiring that was going on (it opens the IAC sensor to allow more air for a higher idle speed). I think that when I reinstalled the distributor, I was a little off the mark. I'd guess I was one toothe off on the gears, and not sure how far off that sets the timing in degrees. But just for the sake of explaining this, let's call it 20 degrees out. Now your driving down the road and you get an engine knock from bad fuel. Your knock sensor sends it another 20 degrees out, the engine stumbles and then you feel like your having a constant misfire (due to bent valves). This may not be your situation, but be careful, I'm pretty sure this it what happened to me. Double check your timing at TDC on the compression stroke of the #1 Cylinder. Keep in mind that there are 2 timing marks on your crankshaft pulley. When rotating the engine by hand (in the normal direction of rotation), the second mark on the pulley that approaches the timing mark is the one you want. Your rotor should then be pointing at the contact for your #1 spark plug wire. One test you can do on your wires is to, with the engine running, spray the wires with water (from a spray bottle that puts out a fine mist). If you see any arching and sparking going on, you should replace them. This also applies to the coil. Another lesson I learned was the value of a compression test. It's simple to do, and can rule-out and save you a lot of troubleshooting time. Hope this info helps!