Engine surge and engine cut out while going down the road.

[Jmckay1]

Hi, I have a 1999 Chevy Suburban K1500 5.7. I was chasing a bad misfire for a while and finally caught it. I replaced EGR valve, MAF sensor, Throttle Position sensor, plugs and wires, spider injectors, cap and rotor. What ended up fixing that issue was a new distributor. Now that it’s running almost perfect, I have a surge at idle and periodically it will cut out for a split second while traveling down the road. Codes are for camshaft position sensor and mass air flow sensor. Both of which are new. I’ve changed the idle air control sensor and that did not help. Any help would be greatly appreciated.

 

[Schurkey]

Verify fuel pressure, assure fuel filter is good.

Assure all "tune-up" items and procedures are in good condition--distributor cap and rotor, plug wires, spark plugs. Verify PCV, EGR, EVAP systems.

Check "Cam retard" or similar--the synchronization between the cam sensor signal and crank sensor signal. Should be + or - 2 degrees at ~1100 rpm.

Verify power wire condition to ignition coil and ignition module.

Connect scan tool, verify EVERY sensor and computer output, fuel trims, misfire counts for each cylinder. Ideally you'd record that data while the vehicle was surging/cutting out, so you can figure out what the sensors and outputs are doing while the vehicle is acting-up.

Check out the official diagnostic procedure for those two codes. Perhaps clear the codes, see if they come back.

 

[Jmckay1]

I appreciate it! I forgot to mention that fuel pump and fuel filter are new. I have checked the fuel pressure at the rail, it’s where it’s supposed to be. I’ll continue to double check everything else. I appreciate the help, thank you.