My 95 Suburban is running lean and has hardly any power when I push on the gas, it hesitates and also dies sometimes when I am stopped at lights. It always starts up and it idles fine in park and neutral, but when it is in drive and reverse it tries to die if you don't give it gas it usually will die. I have replaced the map sensor, iac valve, tps, fuel filter, O2 sensor, I have also checked all of my vacuum lines and they are good, the Egr valve is only a year old same with the plugs, wires, distributor cap and rotor.

Please Help.

 

How do you know it is lean?

 

It smells lean.

 

Try unbolting the exhaust in front of the cat and drive it. Does it act the same way.

 

I will try it, but the cat is only a year old also.

 

what's fuel pressure?

 

How can I check the fuel pressure?

 

Fuel pressure spec for that truck is 9-13 psi. It is a possible cause for the problem but not likely. Those pumps pretty much died completly since the pressure is already low, it is hard to go from almost no pressure to less. There is no fuel pressure test port you must tie into the lines and have a gauge that can read accurate at that low pressure. A couple of psi will make a difference using a cheap gauge

 

It could have a bad ignition coil or pick up coil. Still more likely than fuel pump.Exhuast could smell funny because it is not running correctly

 

I think the intake manifold gaskets need to be replaced, i'm going to replace them I will let you guys know if this fixes my problem.