my 91 RS still runs shoddy
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Joined: Jul 2006
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my 91 RS still runs shoddy
91 RS, 305 TBI, receiving code 44. Replaced external fuel filter, fuel lines, PCV, O2 sensor, followed vacuum hose routing confirmed no vacuum leaks (everything hooked up and hoses have no holes), distributer cap was o.k. as was plugs and wires. there is fuel spray coming out of both TBI's. One side sprays and drips some the other sprays well. It has a full tank of gas and some STP fuel cleaner in it.
Car starts. You can hear the fuel filter energize when key is turned but motor not turned over. Car will sometimes run well for like 30 seconds at a higher than normal idle, then when it slows down to normal idle (OOA 750RPM) the car starts surging between 1500 RPM and 750 RPM eventually stalling. Other times the car will start up and then immediately stall out. I can get the car going down the road but it feels like it is missing and has no real power. It doesn't accelerate when you push the gas pedal, it just stumbles. When you lift off the pedal the car then surges forward. At idle in gear the car more often than not stalls out. The car can be restarted and the throttle feathered to get the car going again.
I just bought the car after it sat in a garage for years. I ran it the day I bought it for 80 miles without a problem. This problem started like the week after the car was first bought. I'm trying to exhaust all methods that I can prior to taking it to a shop. I do have the Haynes manual and have gone thru that but don't have like fuel gauges to test pressure and whatnot.
What my questions are:
Does the metal collar that goes around the TBI that the air cleaner assemply sits on, has a cardboard gasket on that collar. My cardboard gasket on the metal ring (collar) is half there. Obviously the gasket goes something, Maybe there is air getting in through there or leaking through there?
Even though the fuel pump energizes, maybe it is not providing enough pressure (fuel) to keep the car running correctly and it is starving itself? Potentially since the car sat so long, even though I changed out the fuel filter, the inline fuel filter on the fuel pump can be all crudded up and that would restrict the flow?
Comments on things to check outside what I have done are welcome. My intent is to eventually take it to the shop once I've exhausted all issues as much as I can do.
Thanks for the help guys.
Car starts. You can hear the fuel filter energize when key is turned but motor not turned over. Car will sometimes run well for like 30 seconds at a higher than normal idle, then when it slows down to normal idle (OOA 750RPM) the car starts surging between 1500 RPM and 750 RPM eventually stalling. Other times the car will start up and then immediately stall out. I can get the car going down the road but it feels like it is missing and has no real power. It doesn't accelerate when you push the gas pedal, it just stumbles. When you lift off the pedal the car then surges forward. At idle in gear the car more often than not stalls out. The car can be restarted and the throttle feathered to get the car going again.
I just bought the car after it sat in a garage for years. I ran it the day I bought it for 80 miles without a problem. This problem started like the week after the car was first bought. I'm trying to exhaust all methods that I can prior to taking it to a shop. I do have the Haynes manual and have gone thru that but don't have like fuel gauges to test pressure and whatnot.
What my questions are:
Does the metal collar that goes around the TBI that the air cleaner assemply sits on, has a cardboard gasket on that collar. My cardboard gasket on the metal ring (collar) is half there. Obviously the gasket goes something, Maybe there is air getting in through there or leaking through there?
Even though the fuel pump energizes, maybe it is not providing enough pressure (fuel) to keep the car running correctly and it is starving itself? Potentially since the car sat so long, even though I changed out the fuel filter, the inline fuel filter on the fuel pump can be all crudded up and that would restrict the flow?
Comments on things to check outside what I have done are welcome. My intent is to eventually take it to the shop once I've exhausted all issues as much as I can do.
Thanks for the help guys.
2nd Gear member
Joined: Sep 2006
Posts: 575
From: Baltimore, Maryland
RE: my 91 RS still runs shoddy
I would suggest replacing the injectors on the TBI, as well as the collar. The collar you can get from any GM dealer with a decent parts department for under $10, as for the injectors, you might want to look around, but Turbo City sells flow matched injectors that will improve over the original performance, even if the problem wasn't injectors. Those can be found here: http://www.turbocity.com/product_inf...roducts_id=459
As for that in line fuel filter, if it's been sitting for anything more than a year, replace it, and you probably ought to drain and clean the gas tank at the same time. Unfortuanately, the gas you drain from the tank isn't going to be any good, but you don't want to clog your new filter or injectors if you get them. You should also check for spark on your plugs, as well as proper firing order and timing.
And btw, what is a code 40?
As for that in line fuel filter, if it's been sitting for anything more than a year, replace it, and you probably ought to drain and clean the gas tank at the same time. Unfortuanately, the gas you drain from the tank isn't going to be any good, but you don't want to clog your new filter or injectors if you get them. You should also check for spark on your plugs, as well as proper firing order and timing.
And btw, what is a code 40?
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