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Discussion Starter #21
Good catch. I will check that tomorrow. The other thing I noticed that is a whole nother problem. Is the Tcc not locking up
 

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ECM is pulling 4 degrees timing when you're under load. Knock? or....What is the condition of your balancer? New, used? Used could be spun throwing your timing off.
Maybe try backing off timing 4° and do another log run.

Fuel trim info:

524447
 

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Discussion Starter #25
I actually had the timing as low as it would go with the tan wire unhooked before it started to get choppy. That was about 4btdc which is where the manual calls for. As soon as I plug the wire in again, the computer pulls the timing all the way back to around 25-30 btdc. The new cam isn't playing nice with the computer. I am ordering a chip from tbichips.com to try and get that closer to where it should be. With that said, I don't believe that is ultimately causing the lack in power, but I am curious to see if that chip is worth the money. By the way, is there any reason why I can't set the timing where I want it and leave the tan wire unhooked so the computer doesn't manipulate my timing and take it for a drive?
 

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Long term and short term fuel trims seem high, and the O2 voltages .861 and .999 are pig rich. Your O2 and O2 (mv) reflect this. Is the O2 reading steady or does it oscillate like a sine wave? Your long term fuel trim should be close to 0 and the short term will be around 0 to +20 to 0 to -20 depending on what the engine needs. Short term tells you what the engine is needing/doing now, while long term as it implies, is over a certain predetermined time period. There is more info to gleam from this just have to know what the voltages mean and under what conditions they are generated.

Keith
 

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Discussion Starter #27
I agree Keith. There has to be something to gleam from the numbers. I just wish I knew better how to interpret the changes in these numbers. From what you are explaining, my LT Fuel Trim is pretty consistent 9+. It never really drops down to 0 like you are saying And, I dont know what to think based on what you were telling me on the ST Fuel Trim because my numbers are way higher than +- 20. The lowest ST Fuel Trim reading I had was 113 and the highest is 143. Attached is the data for that drive. It includes all the frames for the drive. Just FYI, I was already driving when I started recording. You can see based on the throttle % how hard I am pushing it.
 

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Rod...from a Chrysler?
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Fuel trim numbers for OBD I are different than OBD II. See pic above.
At 113, (-14) ECM is taking away fuel (running rich) and 143, (+16) ECM is adding fuel.
127 (running lean) is perfect stoich, at 14.7:1 air/fuel.
 

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Are you driving in 3rd gear while towing?
 

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I noticed you listed your cam specs, was the cam indicated and degreed to the manufactures recommended timing or just set to gear marks?
 

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Hates: Liver. Loves: Diesel
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Also curious why EGR is at 47% during uphill/foot down. EGR should be active at cruise/part throttle only.
 

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Latest PDF posting shows IAT at -40, Baro at 25"hg Vss at 0 all frames. EGR at 51% at some point. ECT never over 150*.
missing iat sensor?
Baro should be more like 28-29 unless he is in Denver.?
Vss missing?
EGR should work as cutris73 described
ECT indicates engine not reaching operating temp.
 

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I think we've found a few dozen smoking guns.

IAT readings would be causing pig rich. VSS shouldn't cause loss of power, but I'm not sure of that. Coolant temp sensor would further the rich problem. Regardless of whether or not its a thermostat stuck open or a bad sensor, it's reporting colder than normal operating and therefore adding fuel.

EGR should be easy to test on an OBD1. Assuming the EGR valve itself is operating well mechanically, just pull the vacuum line and plug the manifold side, or use hemostats to crimp the vacuum line shut temporarily. Then do back to back mountain climbs. If the test keeps the valve closed, and you experience increased power, then something about that EGR signal is incorrect. The ECM is telling the EGR to be open when it shouldn't. (btw... expect a check engine light if you defeat the EGR but it should go away as soon as you re-activate it.)

My shortcoming here is twofold: 1) I'm not sure but what the ECM is trying to bring up temps by keeping the EGR open? and 2) I'm no OBD1 wizard. I kinda skipped that experience. OBD2 and carburetors/distributors are my jam.
 

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Wait.. just had another look at the pdf. Brake switch on? Not sure about that ECM, but that can cause all kinds of voodoo with OBD2.
 

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Vss , tps, map used to calc load effecting shift points, tcc, egr.
Not sure on gm , if baro is a calculated marker or actual reading, but it should be fairly close to real.
 

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Discussion Starter #37
I noticed you listed your cam specs, was the cam indicated and degreed to the manufactures recommended timing or just set to gear marks?
I didnt degree the cam. I felt comfortable with where things were at as I spun the engine and watched the timing chain go around and the #1 piston hit TDC. Its possible that I am off one tooth, but again, the odd thing with this new engine is that it is acting exactly like the old engine and that engine was completely stock without anyone opening it up.
 

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You should not tow in OD, because of heat build up, a forced downshift once in a while isn't too bad. But if in OD and you start downhill, fluid flow is cut in half when you chop throttle, no way to cool and loose all the heat you made climbing the hill or dragging the anchor. You enter the next upgrade with a nuclear trans.
 

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Discussion Starter #39
Latest PDF posting shows IAT at -40, Baro at 25"hg Vss at 0 all frames. EGR at 51% at some point. ECT never over 150*.
missing iat sensor?
Baro should be more like 28-29 unless he is in Denver.?
Vss missing?
EGR should work as cutris73 described
ECT indicates engine not reaching operating temp.
There are a couple things that the reader never has been able to read. The IAT is one of those. I read that if the IAT shows something like -40, it is basically saying it cant read that or doesnt have the capability to read that with OBD1. As far as the Baro goes, I am at a pretty high elevation in northern Utah. I dont know what to think about the VSS. It may be one that cant be read or it may be something with the wiring. I will check that. With the ECT showing things a little cooler, I took the truck out pretty quick and didnt give it as much time as I probably should have to warm up before taking it for a drive. The EGR is making me think it could be the issue. I will do what Curtis said and test that.
 

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A couple of cam degrees can make a big difference in torque with an other than standard grind. Thats why they make eccentric bushings.
Overlap can act a lot like an Egr valve, leaving a portion of exhaust gas in the chamber. Early on car manufacturers used this before they had reliable egr systems. Dropped CO levels but pushed NO2 levels up.
 
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