Engine hesitation at 3000 Rpms

[BryansToy]

My toy is 87 22RE. What is happening is that the truck hesitate and jumps around 30-3500 rpms mostly after i have driven it a few blocks. It does it in all gears and gets worse when loaded or going up a hill. Some told that it might be O2 sensor or my exhaust leak. I had a exhaust leak between the head and the manifold for a few weeks. I fixed the leak and tried the O2 sensor. Still does it. My question is has this happened to any one else. I could not find anything through the search engine. Is it the fuel system, timing, or electrical. Any suggestions would be great.

Other problem got a 80 toy. I broke the hard brake lines when putting new flex hoses on the front drivers side. Is there any good place in SLC to get new lines? or should i try the online sites to get them. Thanks

[22REkid]

My toy is 87 22RE. What is happening is that the truck hesitate and jumps around 30-3500 rpms mostly after i have driven it a few blocks. It does it in all gears and gets worse when loaded or going up a hill. Some told that it might be O2 sensor or my exhaust leak. I had a exhaust leak between the head and the manifold for a few weeks. I fixed the leak and tried the O2 sensor. Still does it. My question is has this happened to any one else. I could not find anything through the search engine. Is it the fuel system, timing, or electrical. Any suggestions would be great.

Other problem got a 80 toy. I broke the hard brake lines when putting new flex hoses on the front drivers side. Is there any good place in SLC to get new lines? or should i try the online sites to get them. Thanks

There is a couple thinks to concider here. You said that it does it in all the gears, have you checked to see if it does it in neutral? There is a couple things that would cause this 1. Throttle Positioning Sensor (unlikely by what you have described) 2. Mass Airflow Sensor (MAS). Iwould lean more toward a MAS. O2 sensors don't cause driveability problems even if faulty. If you own more than 1 fuel injected truck that is 85-87, you can swap out the MAS and see if it fixes anything. Or maybe your friends have one you can try. Don't swap one that is from an 88' and newer because they are different. If you have a TPS problem, the check engine light would come on and would hesitate in all conditions except for wide open throttle and at idle. The simplest thing to do at this point is to take off the plastic intake hose that goes from the MAS to the throttle body and see if the rubber boot on the throttle body is ripped or cracked. But all in all, it sounds like a Mass Airflow Sensor to me.

[BryansToy]

So it might be the MAS. I will have to try that. Thanks

[D-Krawler]

an easy way to tell if it's the mass air flow sensor, is to start the truck up then go tap on the the m.a.f. box kinda aggressivley. ( i was told to do that by a mechanic when my truck was stuttering around, it ended up being the ecu)

[BryansToy]

It ended up being the fuel filter 4.99 dollar part. It was really plugged bad. It made the fuel pump quietier. So now my truck is as quiet as a toy can get. Thanks for the advice it helped narrow down the possiblies.