91 350 idle while in gear problem

[Blakestuhh]

It might be your fuel pump! Mine was doing the same thing.

 

[CJ91C1500]

lol i actually just did that lol didnt start it had to leave for work gonna grab a cts on way home and throw it in see if it makes a difference if not truck is sitting until income tax comes in then its going to a shop

 

[CJ91C1500]

i really hope its not the pump i did mine in my 96 what a pain in the a$$

 

[KReePiN]

Next time i do a pump.....im cuttin a hole in the bed floor to make it easy.....

 

[Blakestuhh]

Yeah it sucks! Mine still does it a little, my o2 sensor was good. Where is the pcv valve?

 

[94Sierra4x4]

Yeah it sucks! Mine still does it a little, my o2 sensor was good. Where is the pcv valve?

Large vacuum line on front of TBI, goes to passenger side valve cover. (the PCV Valve is the piece stuck into passenger side valve cover).
For TBI anyways..

 

[CJ91C1500]

Ok heres a lil update so fresh tune up cap, rotor, wires, and plugs, new tps, iac, egr, fuel pump, fuel filter, I am runnig out of ideas of what to replace anyome got any ideas?

 

[shibbershabber]

did you ever figure it out?

Mine has been acting up the same way. With the hood open and the air cleaner off, I can hear the TBI sucking air just before the idle shoots back up... yours do that too?

I would take the air cleaner off and take off that collar looking thing off too and look at the injectors, see if they are spraying correctly. If there is any dripping or unevenness to the spray, put a test light on the injector harness to see if you have full voltage to them. If the voltage is low then you should replace the Ignition Control Module as it is responsible for sending voltage to injectors. Maybe even your pickup coil?

Infortunately for me, This didnt work either. I have literally replaced every sensor plug and wire on this thing and nothing has fixed it... sitting at the chevy dealer right now

 

[obswill]

did you ever figure it out?

Mine has been acting up the same way. With the hood open and the air cleaner off, I can hear the TBI sucking air just before the idle shoots back up... yours do that too?

I would take the air cleaner off and take off that collar looking thing off too and look at the injectors, see if they are spraying correctly. If there is any dripping or unevenness to the spray, put a test light on the injector harness to see if you have full voltage to them. If the voltage is low then you should replace the Ignition Control Module as it is responsible for sending voltage to injectors. Maybe even your pickup coil?

Infortunately for me, This didnt work either. I have literally replaced every sensor plug and wire on this thing and nothing has fixed it... sitting at the chevy dealer right now

Did you ever figure out your problem

 

[shibbershabber]

Not really.

Dealer said distributor was bad, put new one in... Was good for a while but started acting up again soon after.

Did the fuel pump and it cleared up again. But then did same thing and started dying on me too.

Thought maybe bad pump... So replaced it again... Drove better... Then I sold it.

My greatest failure and disappointment of my car-owning life.

In hindsight I should have known better than to buy anything from a gypsy. But physically it was so nice, I couldnt imagine it would be such a lemon.

Someone had screwed with it and opened up that box on the passenger firewall and things were messed with. Something had to be Jerry rigged in there.