1998 gmc 1500 will not start. Ran fine yesterday. Cranks over fast. Replaced fuel filter. Has spark at plugs. Checked fuses. Can not tell if fuel is flowing into the manifold.

The Ignition Control Module (ICM) may have failed. It may spark but not when the ECM wants it to. These are problematic components that I recommend replacing every 120,000 miles or 10 years, whichever comes first. Easy 5 minute job to replace.

90%+ of "crank but won't start" situations are ignition system related, not fuel.

Thank you, I will try that.

When you check fuses, use a test light or multimeter to test all under hood and under dash fuses. Be very thorough, since it will save a lot of time and money. Still, ICM failure is common on trucks of this generation. I would be surprised if this did not solve your problem.

By the way, where is the ICM on a 1998 5.0? I just have to wait for a ride to the parts store.

Go to AutoZone.com and look at DR178, $82.99.

What I meant to ask is where is the ICM located under the hood?

Look at what the part looks like--it will be close to the coil. You'll have to take it from there.

Thank you