lT1 PROBLEM-LETS SEE HOW GOOD YOU GUYS ARE
lT1 PROBLEM-LETS SEE HOW GOOD YOU GUYS ARE Ok, Ive Asked Everyone I Know And Im Getting Every Answer You Can Imagine. I Had My Lt1 Rebuilt Along With The Trans. Good Work, Not Done By Hacks. I Put It All Back Together So Thats Probably The Problem. Anyhow, Msd Ignition Is New And A Cam Swap Would Be The Only Things Not Stock. When I Start It It Runs Ok. A Little Rough Idle, Slow To Start. After A While It Heats Up The Cat. The Engine Temp Is Fine But The Cat Is Obviously Hot. Since It Was Glowing Orange. Im Thinkin Its Running Lean. I Tested The Fuel Pressure And Its A Little Low. Normal Pressure Should Be At About 41 To 45 And Its At 36 Or 37. Its Low But Not That Low. Fyi, Every Sensor, Valve, Piece And Part You Can Think Of Has Been Replaced. As Im Writing This Im Almost Certain Someone Is Going To Tell Me To Replace Something That I Havent Already.
I would also think that its a bad catalitic converter.... I've seen cars heat up, cars that won't even start... misfiring... etc, if its glowing... its very clogged... replace/remove ASAP....
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Verdad Gallardo Hey, Infinatebird, I Like All Capitalizing Everything. Deal With It.
Anyhow, I Have Replaced The Converter And Still Have The Problem. I Havent Run The Engine Until It Glows Though, But It Starts Running Kind Of On The Sh__y Side. The Cam -as I Was Told- Was From Comp Cams. The Engine Builder Said That He Called Comp And They Said The Cam Wouldnt Mess With The Computer.
Hey, Paul Bell, So If Its Runnig Lean Could It Be The Fuel Pump?? Or How Bout The Fuel Pressure Regulator? Other Than Those Two Things All I Can Think Of Would Be The Injectors.
Anyhow, I Have Replaced The Converter And Still Have The Problem. I Havent Run The Engine Until It Glows Though, But It Starts Running Kind Of On The Sh__y Side. The Cam -as I Was Told- Was From Comp Cams. The Engine Builder Said That He Called Comp And They Said The Cam Wouldnt Mess With The Computer.
Hey, Paul Bell, So If Its Runnig Lean Could It Be The Fuel Pump?? Or How Bout The Fuel Pressure Regulator? Other Than Those Two Things All I Can Think Of Would Be The Injectors.
Unless the injectors are stopped up they will not cause it to run to lean. I have one of the biggest cams comp makes and I used the stock injectors for a year or so untill I upgraded. I would change the fuel filter just to be sure. I'm with HBH on this one.........check the cam timing. Even without a tune it should still run good enough to drive. Get a fuel pressure gauge and check the FP.....then you can ELIMINATE that as a problem if it's good.
TECH Enthusiast
Joined: May 2005
Posts: 669
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From: Charlotte, NC
Originally Posted by 30696bird
Unless the injectors are stopped up they will not cause it to run to lean. I have one of the biggest cams comp makes and I used the stock injectors for a year or so untill I upgraded. I would change the fuel filter just to be sure. I'm with HBH on this one.........check the cam timing. Even without a tune it should still run good enough to drive. Get a fuel pressure gauge and check the FP.....then you can ELIMINATE that as a problem if it's good.
exactly. I mean common sense will tell you if something is changed, and now there is a problem, the cause is usually in what was changed. The cam was installed and now you have issues. Best thing to do is verify the install. After you rule out internal issues from teh biuld, look to outside sources.
I put a new cat on there and It still runs like crap after a few minutes. How do you check cam timing? You dont have to pull everything off the front of the engine do you? Would cam timimg really be an issue if the car runs pretty nice for the first 4 or 5 minutes and slowly gets worse. How bout I have a party at my house with all you guys and we can get my car up and running. Free beer and food 
Originally Posted by REBORN Z28
car runs pretty nice for the first 4 or 5 minutes and slowly gets worse
O2s and a TUNE. I don't care what Comp and the builder said a cam needs a tune, the fact the builder said it didn't would send chills down my back. A stock car benifits GREATLY from a tune a modified one it is required.
The problem here sounds to me though like you went and screwed with a bunch of working stuff, A LOT of folks rebuild these things when having no problems and endup with nothing but problems.
If your car is a 94-5 or a 96-7 you are willing to swap to OBD1 I can load programming for you if you would want to meet at WIR, you would just need to have a professional email you a tune and then email it to me or bring it on floppy. You would not be the first guy I helpedout like this and who was awestruck at the difference a tune made.
The problem here sounds to me though like you went and screwed with a bunch of working stuff, A LOT of folks rebuild these things when having no problems and endup with nothing but problems.
If your car is a 94-5 or a 96-7 you are willing to swap to OBD1 I can load programming for you if you would want to meet at WIR, you would just need to have a professional email you a tune and then email it to me or bring it on floppy. You would not be the first guy I helpedout like this and who was awestruck at the difference a tune made.
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Joined: May 2005
Posts: 669
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From: Charlotte, NC
02's don't directly effect the way the car runs ( altleast in a negitive effect). At a point even if the 02's were bad and reading to the limit that the adaptive can control, it's not going to matter much. The most that a faulty 02 can do is play tricks on your mileage, and make for a slightly rough condition from over fueling. It's not going to create a huge problem, but the condition driving them lean/rich will.
To correctly check your timing, timing cover needs to come off, but you need to start at the base and work your way up from there. Pull it off, make sure that you have timing lined up, verify that the cam dowel pin is the correct length and that the pin is in the correct grove of the opti (95-97) or that the spline shaft is installed correctly with the double grove in the right spot (93-94)
To correctly check your timing, timing cover needs to come off, but you need to start at the base and work your way up from there. Pull it off, make sure that you have timing lined up, verify that the cam dowel pin is the correct length and that the pin is in the correct grove of the opti (95-97) or that the spline shaft is installed correctly with the double grove in the right spot (93-94)
OK, a little update. Checking the fuel pressure again I thought swapping the fuel filter would help. Nope. Oh well, its only 8 dollars. Im only under by 3-4 psi. No big deal right? The pressure stays there too. Moving on now, what about the EGR system? Maybe the EGR valve is junk?
Also the O2 sensors are new, and heres the codes and descriptions I have.
32-EGR valve bad
96-trans voltage low
95-oil level sensor voltage
94-???? Couldnt find
65-right bank O2 sensor/rich exhaust OR Injector current low OR EGR bad
33-MAP sensor voltage high OR MAF sensor voltage high
22- TPS voltage low
21- TPS sensor problem
Since getting these codes Ive replaced the TPS-throttle position sensor,MAP- manifold absolute pressure sensor, and PCV-positive crankcase ventalation valve. Still runs like crap. Oh yea, the fuel filter too.
Also the O2 sensors are new, and heres the codes and descriptions I have.
32-EGR valve bad
96-trans voltage low
95-oil level sensor voltage
94-???? Couldnt find
65-right bank O2 sensor/rich exhaust OR Injector current low OR EGR bad
33-MAP sensor voltage high OR MAF sensor voltage high
22- TPS voltage low
21- TPS sensor problem
Since getting these codes Ive replaced the TPS-throttle position sensor,MAP- manifold absolute pressure sensor, and PCV-positive crankcase ventalation valve. Still runs like crap. Oh yea, the fuel filter too.
TECH Enthusiast
Joined: May 2005
Posts: 669
Likes: 0
From: Charlotte, NC
I'm telling you. Start at the beginning and verify cam timing and opti location as well as cam dowel pin length. You need to start at the bottom and work your way up. These codes can all be explained by loss of vacuum because of incorrect timing. You need to find a point of reference. Check the timing.