I have a 96 Suburban that has been very dependable. It has the 5.7 motor. This morning, I went out to start it, and it ran very rough, hesitating, etc. Once on the road, it stalled several times at lights. It runs fine under load, but it is not idling propertly. It also hesitates when you first give it gas. After about 3-4 miles of driving, the "service engine soon" light came on. It's the first time I've ever seen it come on. Plugging a code reader into it, I got no codes at all, which is very unusual, since I always had readings before. The exhaust also has a strong gas smell like it's running rich. Could it be the ECM/ECU starting to go....or could you point me in the right direction?

 

fuel pressure regulator could be leaking its located inside the upper intake manifold on the injection spider or a possible sticking poppet valve in one of the injectors,whats fuel pressure?

 

I found out what it was....Believe it or not the vacuum hose from the engine to the brake booster had a crack in it. If the engine was idling, the crack was larger, but as I revved the engine up, because of the torque moved the engine slightly toward the booster, the crack would close up. I discovered this when I drove it to the shop I use. As I pulled in, the brake pedal got hard, like no vacuum, and I heard a leak. Opened the hood, and lo and behold the hose had broken off completely from the plastic nipple on the booster.

 

good to hear cheap and easy

 

LOL>...funny, this all started in Middletown, DE. My son lives in Cricklewood, and we were there Saturday for my granddaughters Birthday party. It was there 1) my brakes went out, due to a pinhole in the metal line over the axle, and once i fixed that, 2) the missing started. I never touched the vacuum line, but the truck had been stumbling when first started for over a year. Go figure, the brake line cost me $12 bucks and 4.5 hours. The Vacuum line hose end cost me $10 bucks. $22 dollars and its back to normal, Thank God.