Good morning gents - would you care to pitch me some ideas on what to replace that isn't broken (yet)? My 2001 Express LT is in great overall condition, and it's my daily driver. It does, however, occasionally fail to start and has even stranded me a couple of times, so I want to do a round of replacing things that aren't broken to get ahead of the repairs. I have a good mobile mechanic and he's had solid suggestions over time, and any time we do a repair, I ask him if we can replace any related parts or anything he finds that's still an original part, but I want to dig in even deeper and get farther ahead of the deterioration. I would hire him to come for a couple of days and replace everything that is old or suspect, if I can get a good list going. Spending a few thousand is completely fine - it's "free money" compared to replacing the van. It has just 165k miles and the engine is good. I have replaced starter, alternator, radiator, hoses, AC compressor, all the ignition parts, brakes, brake lines, fuel injection spider, wiper motor, fuel pump, and just about all the typical degradable parts. It is frequently coding for misfire for one thing or another - annoying. I have had repeated problems with cavitation and rough idle that have been elusive - it will run, but intermittently runs rough. Oil pressure fluctuates and I suspect the O ring on the pickup tube.
What do restorers typically replace? My dad was a restorer, but he's no longer with us. Just for example, would you replace all the relays? Would you replace the ECM? If so, is there an upgrade that doesn't require any other modifications? I am told not to expect much in regards to performance from a 5.7l in a full size van, but having been a lifelong, 3rd generation GM driver, I know the performance could be better, so I wonder if there is something in the fuel delivery or air intake system that is underperforming, and we haven't discovered it because it isn't exactly broken. Could there be back pressure from the old catalytic converter? Thanks in advance for suggestions.

 

remove the O2 sensor or put a gauge on it and see

 

Strangely, I posted this question yesterday, and the title inquiring for suggestions on getting ahead of repairs got remotely changed to 'intermittent start and rough idle' - which did not match the post content, so understandably, readers would have thought I didn't know what I was talking about. Starting over: Good morning gents - would you care to pitch me some ideas on what to replace that isn't broken (yet)? My 2001 Express LT is in great overall condition, and it's my daily driver. It does, however, occasionally fail to start and has even stranded me a couple of times, so I want to do a round of replacing things that aren't broken to get ahead of the repairs. I have a good mobile mechanic and he's had solid suggestions over time, and any time we do a repair, I ask him if we can replace any related parts or anything he finds that's still an original part, but I want to dig in even deeper and get farther ahead of the deterioration. I would hire him to come for a couple of days and replace everything that is old or suspect, if I can get a good list going. Spending a few thousand is completely fine - it's "free money" compared to replacing the van. It has just 165k miles and the engine is good. I have replaced starter, alternator, radiator, hoses, AC compressor, all the ignition parts, brakes, brake lines, fuel injection spider, wiper motor, fuel pump, and just about all the typical degradable parts. It is frequently coding for misfire for one thing or another - annoying. I have had repeated problems with cavitation and rough idle that have been elusive - it will run, but intermittently runs rough. Oil pressure fluctuates and I suspect the O ring on the pickup tube.
What do restorers typically replace? My dad was a restorer, but he's no longer with us. Just for example, would you replace all the relays? Would you replace the ECM? If so, is there an upgrade that doesn't require any other modifications? I am told not to expect much in regards to performance from a 5.7l in a full size van, but having been a lifelong, 3rd generation GM driver, I know the performance could be better, so I wonder if there is something in the fuel delivery or air intake system that is underperforming, and we haven't discovered it because it isn't exactly broken. Could there be back pressure from the old catalytic converter? Thanks in advance for suggestions.

 

are you getting a code for a miss fire on a particular cylinder or bank. if so that cat maybe clogged. it happend to my van. disconnected the exhaust at the manifold on that bank and problem went away. then changed the cat...