My 94 suburban, with a new FSD located on a heatsink in the bumber cooling holes and new OPS, is a POS. It is still missing during accelleration and even during cruise sometimes, then other times it runs just fine under these same condition. Do I replace the pump? Do I replace the injectors? Do I replace the truck? I really like my suburban but Im tired of throwing parts at it. There is no check engine light coming on either.
Let me know what you guys think.

 

Does it seem to produce white smoke at start up and seem to have what smells like raw fuel?

 

not allot of smoke, just a little for a few seconds, and it will sputter for a 1 or 2 seconds, also once in a blue moon if I dont let it run for a little bit after I start it and take off right away, it wants to stall, if I dont get off the gas right away and pump the pedal, it will quit.

 

Have to crank it over longer than usual to start it?

 

no, it starts right up

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It starts right up, and chugs/smokes for no longer than 3 seconds, unless its really cold out, like today 10F then its chugs for a while and you need to give it gas so it doesnt quit, but only for 30 seconds to a minute.

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Also, the FSD, is only connected to the extension chord, is it supposed to be grounded or something, My lift pump clicks on and off with the glow plugs, but doesnt vibrate or anything.

 

You plug the block heater in?? Could also be the idle needs to be kicked up a few rpm's.

 

i havnt found the block heater if there even is one,

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the idle doest solve the missing during accell, is the lift pump supposed to vibrate when the truck is running

 

Maybe should get one, they help out a bunch. As far as the fuel pump, they will vibrate a little. Everything is stiff, including the oil when it's that cold out, which is why it's needing a little more rpm to keep going. If it's still missing at full operating temp, I'd look at getting the injectors checked out or a compression test done.

 

I just found the block heater and plugged it in, , There is absolutley no vibration coming from the lift pump (one under the seat on frame rail). I unplugged the ops and the truck ran , but obviously pegged the oil pressure guage. but it didnt run any different. So will they run without the lift pump operating, and if that is the case, I think that may be the problem. Its running w/o a lift pump. what do ya think?

 

I guess it depends on the type of lift pump, whether or not they vibrate. I guess what you can try and do is loosen or remove the line after the pump and see if fuel squirts out and how hard/fast.