Erratic idle and spitting and sputtering on stop and go and backing up

[ff119]

Hello all, this 1994 Chevy Suburban 2WD 1/2 ton is really testing my skill kit, so far I have done a complete tune up, at one point I thought it was running very well just to end up frustrated, I have installed new plugs, wires, cap rotor and now a new distributor as of 9/3/17 (today) I also have replaced the temp gauge sensor, coolant temp sensor near the thermostat housing, and this thing wants to die when taking off from a complete stop ( traffic light, etc ) it wants to die when backing up and coming to a complete stop, etc. I swapped out the TBI unit with another one, cleaned the EGR valve, I just can not figure this thing out, the only thing I haven't done is replace the fuel filter and affraid to do so in fear of braking a fuel line and buying a new fuel pump, and doing a compression test, Anyone have any thoughts they would like to share ? Thank you

 

[jwd621]

If it was mine, I would try a can of "Seafoam" in the fuel tank to diperse any moisture in the fuel. Worth a try for a few $$ in light of how much you already spent.
Please keep us posted, events like this helps everybody learn.

 

[zora]

you make no mention of the mileage on the vehicle, if high mileage a compression test is due.
do you have a check engine light on and do you have any codes?
have you done a fuel pressure test?
how do you know the replacment TBI had no issues?

 

[ff119]

you make no mention of the mileage on the vehicle, if high mileage a compression test is due.
do you have a check engine light on and do you have any codes?
have you done a fuel pressure test?
how do you know the replacment TBI had no issues?

You make a valid reply Zora, the mileage is 186,000, compression check all dialed within limits, no check engine light and no codes, fuel pressure is also within limits and took the TBI off what I believe a good running motor, otherwise, I'm at my wits on this issue, my next step is to check the cat, I'm wondering if possibly it might be restricting the flow, pressure at tail pipe seems weak when placing my hand in front, I have already removed what appears to be the big OEM muffler with a aftermarket muffler.

 

[zora]

here is a link on testing for a blocked converter
http://www.aa1car.com/library/converter.htm