94 chev van, no power, lousy gas milage

Tiny
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I am still inclined to think the spark ping on hills is a clue, mostly because the other tbi truck does not ping
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Friday, September 7th, 2012 AT 6:33 PM
Tiny
KHLOW2008
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I agree with that but what is causing it? Timing out of sync? Excessive carbon in cylinders?
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Friday, September 7th, 2012 AT 7:03 PM
Tiny
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Any way to check the Timing out of sync theory without dismantelling the engine
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Friday, September 7th, 2012 AT 7:26 PM
Tiny
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No, you would at least have to remove the covers.
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Friday, September 7th, 2012 AT 7:57 PM
Tiny
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Took this thing out yesterday with an old auto xray scanner hooked up to moniter as I drove. Went about 8 miles to warm it up to a long hill that the vehicle does not like to climb. As usual it pinged loudly as soon as the hill slowed it down. What I found interesting is that the knock sensor showed 0 response and the knock retard showed 0 degrees. Other readings were coolant temp 194.9, engine run time 1800 secs, egr cycle0%, ccp duty cycle 0%, ccp purge off, idle kicker 0

the retard and egr do not appear as they should. Does this information shed any light on the problem
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Sunday, September 9th, 2012 AT 12:15 PM
Tiny
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The ECU does not seem to be responding to conditions and maybe it is the one at fault. ECU can fail over time due to bad capacitors. If you can get you hand on an ECU, give it a try.
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Sunday, September 9th, 2012 AT 1:34 PM
Tiny
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Ok, probably take couple of days to get one with the same number.
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Sunday, September 9th, 2012 AT 3:03 PM
Tiny
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Good luck.
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Sunday, September 9th, 2012 AT 4:07 PM
Tiny
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Any trick to replacing it, do I just unplug the old one and plug in a new one. Do I have to take the battery cable off or anything else .
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Sunday, September 9th, 2012 AT 4:14 PM
Tiny
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Disconnect the battery negative terminal first.
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Sunday, September 9th, 2012 AT 4:21 PM
Tiny
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Ok, I have a used computer complete , correct number, from a 94 s10. Do I have to change the prom anything else before I install it. This is a conversion van with the computer located behind the b pillar
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Saturday, September 15th, 2012 AT 10:32 PM
Tiny
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Disconnect the battery negative terminal. Disconnect PCM. Reinstall new unit. Reverse procedures for installation.
Run vehicle to let the PCM relearn.
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Saturday, September 15th, 2012 AT 11:02 PM
Tiny
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Wow, you guys are fast. Will do tomarrow and let you know what happens
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Saturday, September 15th, 2012 AT 11:13 PM
Tiny
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Installed replacement pcm. Ran about 20 miles, non highway, about 45 mph. Did notice difference. Spark retard showed up to 5 degrees retard and showing activity on knock sensor. Feels smoother. But the service engine light is on and no codes. Should I install original prom .
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Sunday, September 16th, 2012 AT 1:38 PM
Tiny
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If the service light is on with no codes, it can mean the replacement PCM has a fault too. Yes, I would like you to retest the original PCM to see how it works.
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Sunday, September 16th, 2012 AT 4:45 PM
Tiny
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Do you mean the original prom?
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Sunday, September 16th, 2012 AT 6:05 PM
Tiny
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Yes
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Sunday, September 16th, 2012 AT 6:36 PM
Tiny
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I TRIED PUTTING THE ORIGINAL PROM IN THE S10 COMPUTER. ALL MY PROBLEMS RETURNED IMMEDIATELY. SOOOOOOOO I PUT THE ORIGINAL COMPUTER BACK IN THE VEHICLE WITH THE S10 PROM INSTALLED. The improvements were immediate. Question is what problems will it cause using a 6 cyllinder 4.3 prom in an 8 cylinder 350 van
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Thursday, September 20th, 2012 AT 11:51 PM
Tiny
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6 and 8 cylinder don't mix. To get the engine started itself would be a miracle and to get it to run perfect, the manufacturer would like you to be in their R&D division.
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Friday, September 21st, 2012 AT 6:31 AM
Tiny
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It works so much better with the 6 cylinder chip. What possible damage will it do if I run it till I can get the correct prom
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Friday, September 21st, 2012 AT 6:32 PM

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