rcolon646

I have a 91 Chevy caprice wagon with a 305 v8 motor that i love with all my heart. well unfortunately it would not start up anymore. I have done a full tune-up and still no luck. Im now at a stand still because i have somebody telling me to change the distributor and another person telling me that I need to change the timing chain. the car sounds like it wants to start but just wont do it. the distributor has spark at the coil but no spark at the number 1 plug?? please somebody help me I dont know what to do with my baby.

2wd-K5

u need a new module ill bet, they usually go on them

therewolf

Hi rcolon646,

Welcome to the Chevy Forums.

There's an ECM under the vacuum plate of your distributor which goes bad when the dielectric grease dries out. Change it, grease the new one well.(the metal plate on the bottom) I haven't priced one recently, but I'd guess they're @ 12 to18$$.

Then I'd consider a change out of the big three.

2wd-K5

a change out of the big three? u mean the domestics?

therewolf

Ya-har-har, I wish.

No, I was referring to the battery cables and the engine-to-firewall groundstrap.

Many times a bad wire imitates another problem. In any event, when the vehicle starts to age, bad cables are directly tied to alternator, starter, and battery failure.

They're inexpensive, but many pro mechanics will dog you and leave them in, because they know you'll be back for a lot of other stuff as a result.

2wd-K5

right on, didnt know that about the mechanics though, good to know even know the only things mechanics ever touch is exhaust (sometimes) and tires on my vehicles

in2pro

Very true, and with any engine anomalies this should be the first thing checked... feel the entire cable length for any unusual stiffness as that could be corrosion build up inside the wire jacket...the cable can look fine from the ends but the inside can be bad... look for splits and cracks, ohm out the cable it should read less then 4 ohms..
also when repairing a cable don't break away too many strands( none if possible) as that can reduce the current load of the cable...

therewolf

For instance, what could be happening here is:

The negative wire is badly corroded, but works OK cold. When the engine heats up, the corrosion in the wire heats up, increasing resistance to the battery voltage.

A dead giveaway to this problem in that event, is after a few start attempts, one or both of the battery cables would be VERY hot(@150 degrees)

Cables are cheap, I replaced all mine on my '04 in 2008, and I'll probably do it again in a couple years. If you wait till you replace the battery anyway,(stereo upgrade, or just age) you can also fit a top-mount battery in the larger vehicles. I did, and I've never been happier.

RakerBill

A quick way to see if it is your timing chain is bad is to pull the distributor cap off and have someone crank the engine and see if the rotor is turning. Make sure and watch for spark from the coil as it can give you a nasty shock.
If it's not turning, then you either have a busted timing chain, or a busted gear on the dist.

therewolf

I know I baby the crap out of my truck, it's the first vehicle I've ever had since new.(got it with 17 miles on it) I probably give that truck 3 times the attention that it needs. So I think I know how you feel, OP.

If the new ECM doesn't change the picture, pull the distributor, and check the distributor cam gear.(at the distributor base)

Then it would be time to pop off the timing case cover. First look to be sure you have no broken timing gear teeth, regardless of the quality or type of the gears.
Then carefully inspect the timing chain for stretching.

Then bring piston #1 to TDC, and make sure the timing marks on the gears line up.