No power and struggles above 30 mph
 

2001 blazer.

So I was on my way back from a 18 miles trip on the interstate at 75mph then to 65mph. I slowed down to merge on the other interstate and went to put my foot back on the gass. I had tons of surging until is slowly got back to 65mph. I decided to exit the interstate. Car would idle fine but when I got around 30 mph (speed limit 35mph) I would start having it surge until it go to what it needed. I went straight home and turn the truck off in the driveway. I went to go start it again. It would just turn over and not start. My fuel level was down to 1/4" of a tank so I added a gallon of gass in. Still no difference. Came back out 10 minutes later and it started just fine. I have not drove it sense. I have drove it around with 1/4 tank of gas before without an issue. I'm going to check the mass air flow sensor. I have a check engine light but that is for another issue (2nd air injection system.). I have had it for a year without a problem. So I pulled the codes and nothing new. Anything else you guys need? Also I put the truck into neutral and in the drive way or driving. It still surged above a certain rpm. Just not a bad.

Thanks,

Josh

Fuel pump failing because of overheating? I'd check the fuel pressure in the system.

I would also check your fuel pressure.
you can rent a fuel pressure tester from most autoparts stores.

edit: ^ beat me to it.

+1 on checking the fuel pressure. You need to eliminate that before you do any more troubleshooting.

Some of the most likely causes:

Fuel pressure (follow the advice you have been given)
Vacuum leak
Air intake leak
Transmission problems
Electrical/ignition issues
Exhaust restriction/cat

If you have a scanner look at fuel trims at idle and 2500 rpm's which might help narrow it down. You need ST and LT for both banks, observing sign (+/-).

George

Got the word back from the mechanic. Clogged exhaust (probably cat.). 6 psi during snap throttle test while parked. I went ahead and had them due the fuel pump / filter anyway. When I first got the truck. It was growing at me. The growling went away but once in a while it would take a sec to start. So I'll see if that problem goes away. If anything it had the factory pump in it. Just being on the safe side. I'm crossing my fingers that once I get the clog fixed it will fix my 2nd air injection error code. Also I'm pretty sure it is was killed the egr value last fall. But I'm not sure how bad 6psi is. Anyway I'll post more when I have some more answers.

Thanks,

josh