Re-truck trouble HELP

[LandfillLumber]

Hello, so I'm a little stupid about autos and thought that my truck was not going into first gear as it was acting like i was trying to take off in third.I was wrong its going into first but it will not take off normal,it jerks and acts like it doesn't want to burn the fuel.My uncle said that he thought it was a air line that goes from the air filter to the top of the engine.Is this the lines coming from the manifold?I have one that goes from one manifold to under the carb,then one that was not attached to anything coming from the other manifold.The air filter has a port for a line but it is larger then the hose coming from the manifold?I'm sure I'm just confusing people as I'm very confused myself.Any help would be great,Victor

 

[NewLondon88]

Have you tried blocking that hose or the opening on the manifold to see if
you get any change? I have no idea, can't picture it in my head.

 

[mredburn]

what kind of truck? does the checkengine light come on?

 

[wolftat]

Now your opening a case of worms. It could be a blocked egr valve, a clogged fuel filter or it could be a bad O2 sensor. I have a '90 c3500 and I have replaced the O2 sensor a couple of times due to issues. The possiblilty that a vaccuum line is cracked is always good in an old truck too.Do you have the 5.0 or the 5.7, i don't think you have the 7.4 motor.

One more thing, did this start to happen shortly after filling up your fuel tank?

 

[LandfillLumber]

Hello, everyone its 88 Chevy Cheyenne that has I think a 305 in it(this truck was someones project truck trying to make it a hot rod)so many things are not stock as far as I can tell.I have wire connectors hanging all over that go to nothing at all so its hard to tell what is what for me a carpenter.It only runs bad while taking off in first gear, I take off in reverse and nothing is wrong.I did a scan on the truck and got a code 34 that is supposed to be a Mass air floe sensor(MAF)/or a manifold absolute pressure sensor(MAP)/or Pressure sensor circuit.I think from what I read that MAF's are for fuel injection cars only???I have read so much I'm getting really confused.HELP,Victor

 

[LandfillLumber]

It happened shortly after a fuel up but I would say I put on 80 miles before it happened.In my truck 80 miles a a good amount of gas.The check engine light does not come on.Victor

 

[wolftat]

I would start by replacing the O2 sensor, that should take care of the issue. The 5 litre is a decent motor, but it's not what most would choose for a hotrod project.

 

[nava1uni]

It sounds as if there is a vacuum hose that is either loose or is cracked. This is a closed system and if there are any vacuum leaks it will not drive. Check where the vacuum lines are attached. If the tubing is hard or brittle, it should be replaced since the system will be leaking. If it is just the end then you can cut the end and replace it and it will be a tighter fit. Check all of the hosing because it can look solid, but have tiny cracks that will let air in and cause a problem.

 

[Displaced Canadian]

I had a 74 chevy with a 454 the only problem I had was the gas gauge moved faster than the speedometer.

 

[Chief Hill]

I had a similar problem with lagging off the start. It turned out to be bad plug wires/ bad spark not ignighting fuel. Make sure plugs wires dustributor cap is ok. Mine needed a full dvom diagnostic scan to find a bad wire.

 

[Tuba707]

Hello, everyone its 88 Chevy Cheyenne that has I think a 305 in it(this truck was someones project truck trying to make it a hot rod)so many things are not stock as far as I can tell.I have wire connectors hanging all over that go to nothing at all so its hard to tell what is what for me a carpenter.It only runs bad while taking off in first gear, I take off in reverse and nothing is wrong.I did a scan on the truck and got a code 34 that is supposed to be a Mass air floe sensor(MAF)/or a manifold absolute pressure sensor(MAP)/or Pressure sensor circuit.I think from what I read that MAF's are for fuel injection cars only???I have read so much I'm getting really confused.HELP,Victor

Yeah, MAFs and AFMs are a FI part. The measure the airflow and tell the engine computer what to do.

Take some pictures and also tell whether the problem was sudden or gradual.

BTW, you can check for vacuum leaks by spraying a little bit of carb cleaner around possible leak points while the engine idles. If the idle increases, there is a leak there.

Might be time for a full tune-up anyway - fuel filter, plugs, plug wires, distributor rotor/cap, air filter, clean the carb, etc.

Bad or lazy 02 sensors often cause the engine to run slightly rich, often affecting mileage but not anything serious. They don't even start kicking readings back until they reach ~600F.