'95 LT1 loading up heavy, no codes being shown
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'95 LT1 loading up heavy, no codes being shown
I have a 95 LT1 100,000 miles, fuel is loading up and car is missing bad. Had done this once before a couple weeks ago ( about 6 miles) but cleared up. This time it kept missing, seems like it dropped 3 cylinders. I took it to a local garage looking for some sort of code. None available, they also tested the fuel pressure and said it was good. Spark Plugs,wires and temp sending unit to the computer have been changed with no improvement. MAF cleaned with contact cleaner also no change. Here's the kicker, in traffic yesterday ( at red light) when the cooling fans cut on, the miss seemed to stop but the engine light came on. Four min. later the fans cut off and the light went out and the miss started again. Anyone have any idea?
Melting Slicks
Joined: Oct 2004
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From: Austin Texas
I am not sure what you mean by "fuel loading up", but if your SES light went on, then an error code for this problem should get stored. The code will remain in memory even though the SES light went off. You can save yourself the hassle, and easily pull the codes yourself. 
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Loading up as if the injectors were stuck open and dumping gas. The smell of raw gas coming out the exhaust with the smoke to go with it. Seems like you could get into it hard going down the road and blow it out but it doesn't work. I read some of advise you gave to another reader (rwsduc 92 automatic) and tried to get the code. Even went to www.obd1.com for answers. Mine has a 16 pin and I don't know which ones to jump for the SES code.
Melting Slicks
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From: Austin Texas
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Still not sure about fuel pressure regulator. Since it works on vaccum, if I unplug it, cap vaccum line. And drive it down the road it should starve for gas and possibly shut off if you get on it, right?
Racer
Joined: May 2004
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From: DFW TX
Originally Posted by Dado
Loading up as if the injectors were stuck open and dumping gas. The smell of raw gas coming out the exhaust with the smoke to go with it. Seems like you could get into it hard going down the road and blow it out but it doesn't work. I read some of advise you gave to another reader (rwsduc 92 automatic) and tried to get the code. Even went to www.obd1.com for answers. Mine has a 16 pin and I don't know which ones to jump for the SES code.
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Originally Posted by Dado
Still not sure about fuel pressure regulator. Since it works on vaccum, if I unplug it, cap vaccum line. And drive it down the road it should starve for gas and possibly shut off if you get on it, right?
Le Mans Master
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Originally Posted by vetster86
I narrowed it down between injectors or the ecm. I had heard that the LT1 injectors are known for leaking not when the engine is off but when the engine is running. I also got a gas smell after I shut the car off. I changed out the injectors and no more thumping no more gas small and runs better than ever. Also try unplugging your air flow sensor and see if conditions change.
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Orginal injectors and this is not a little miss, it will actually jerk as you drive it down the road.
Just removed the plugs again. L/H side clean as new, R/H side fouled. This wasn't the case the first time. But does this sound like the Opti spark?
Just removed the plugs again. L/H side clean as new, R/H side fouled. This wasn't the case the first time. But does this sound like the Opti spark?
Melting Slicks
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From: Austin Texas
Originally Posted by Dado
Pin 4 and 12 still no code. SES doesn't even flash>>> 
Anyway, your problem appears to be more serious than a faulty O2 sensor or TPS switch. But go ahead and see what codes you get. Is your Optispark original? If you have 100K miles on your Opti, then this could be your problem. Check to make sure your water pump is not leaking through the weep hole onto the Opti, weep hole is at the bottom of water pump. Has the engine been exposed to alot of water recently. Anyway, I've read where Opti's should be replaced every 60K miles as routine maintanance....
Last edited by MikeC4; Feb 12, 2005 at 12:41 AM.
Racer
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From: DFW TX
Originally Posted by Lone Ranger
What injectors did you end up going with as replacements? My '95 almost has the same muffled "wump" in the exhaust note, but only at idle and fades away when going off idle. I've always felt my car has ran slightly rich, even changed the oxygen sensors this fall with only 40,000 miles on the car to see if it would help lean it up some.
Last edited by vetster86; Feb 12, 2005 at 05:59 PM.
Le Mans Master
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Originally Posted by vetster86
I ended up going with the LS1 injectors and they work very well, You just have to do a little mod to them so your fuel rail clips will fit. I did a thread awhile back called ( anyone running LS1 injectors in a LT1 if so..........) I think its back around the 5th or 6th page.
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Update: Finally got the codes pulled, thanks MikeC4. 63,64 both reflect O2 sensor R/H side. Went ahead and replaced sensor and plugs again tonight. Have not tried to drive it yet. Idles fine, no smoke yet. Got my fingers crossed.
