94 S10 Blazer LT TAHOE/16196395 BHRJ PCM

:mad1: I will start by saying that I really enjoy this site. Great information and I hope that one day I will be able to help some one like I am about to ask for now. I have replaced the fuel pump, filter, CPI supply and return lines, EGR, IAC, Distributor, cap and rotor, wires, plugs, TPS, vacuum lines, intake gaskets upper and lower, O2 Sensor. Cleaned the upper intake checked for vacuum leaks, re-torqued the intake, Compression checks and even lapped the valves in both heads because I was bored..(Not really...I was just eliminating a PSI difference). I have downloaded TunerPro V5 along with what I think are the BIN ADF and ADX files that match my setup. The truck will not accelerate. Since I am newer to the ODB1 troubleshooting, I would like to see if anyone can spot my problem in the test run files. I am trying to get the truck going for my son. I have been working on it since June. Any help would be greatly appreciated as my savings account it not keeping up with the demands of this truck. Thanks in advance

BHJR is an $0D bin file, so would need to data log with A217 $0D TP5 v250.adx

http://www.gearhead-efi.com/Fuel-Inj...Information-OD

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Originally Posted by Sp33djunky

:mad1: I will start by saying that I really enjoy this site. Great information and I hope that one day I will be able to help some one like I am about to ask for now. I have replaced the fuel pump, filter, CPI supply and return lines, EGR, IAC, Distributor, cap and rotor, wires, plugs, TPS, vacuum lines, intake gaskets upper and lower, O2 Sensor. Cleaned the upper intake checked for vacuum leaks, re-torqued the intake, Compression checks and even lapped the valves in both heads because I was bored..(Not really...I was just eliminating a PSI difference). I have downloaded TunerPro V5 along with what I think are the BIN ADF and ADX files that match my setup. The truck will not accelerate. Since I am newer to the ODB1 troubleshooting, I would like to see if anyone can spot my problem in the test run files. I am trying to get the truck going for my son. I have been working on it since June. Any help would be greatly appreciated as my savings account it not keeping up with the demands of this truck. Thanks in advance

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Timing set correctly? I worked on one of these trucks recently that had never been touched in 171K. The spider was leaking and and it had numerous vacuum leaks. I got that knocked out and it still just didn't run right. I checked the timing and it was at about -6 or -8. It needs a timing chain someday but it runs good. I bumped it up to about 4°BTDC. On dry pavement it would smoke both rear tires through most of 1st gear. You might have a slipped dampner.

I will advance the timing just for S and G's as a trouble shooting option. I also had a leak in the CPI supply line. I was going to check the timing chain but got lazy due time constraints. Should have done it while I had down to that level but did not want to deal with the oil pan gasket. This engine only has 120K to the best of knowledge.

I will download the updated file and double check. Funny thing though...I read that post so many times and almost downloaded it until I found the BHRJ file. More to follow I guess. I still may ask how to add the Manifold Performance valve to the monitor list. I am not sure it is working cause I have not found a way to rule it out.

Downloaded the new file and numbers still look about the same to me. Once it goes into closed loop, everything starts to go to crap. Driveway test only because the engine just did not run smooth enough for a road test. Changed the timing to test the theory but still no luck finding the sweet spot. What am I missing? I normally can figure these out but that is with the Old school set up.. Yes I mean carb...:mad1: Might just be time to sit back and enjoy a cool beverage.

BLM from 148 idle to 160 off idle and a Error 44 O2 sensor lean all point to one thing! Not enough fuel. Check fuel pressure.

New fuel pump, filter, and pressure regulator. After the change out, at idle the fuel pressure was 52 psi with an increase to 58 when the throttle was opened. I changed out the pump to rule out any pressure problems. I changed out the regulator when I did the CPI supply and return lines. I have not changed out the CPI assy. I did run Injector cleaner through the system before I changed the pump and filter. The CPI spider assy would be the only old part in the equation. I could only speculate that it would be a blockage in one or more of the injectors or the CPI base itself. Thank you for the second set of eyes. I will go back again and double check. If nothing else, there will be a new CPI assy installed tomorrow.

Have you tried artificially enriching it when it is running so rough. If it smoothes out when you put some propane from an unlit torch in front of the throttle plate it is a lean misfire.

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Originally Posted by EagleMark

BLM from 148 idle to 160 off idle and a Error 44 O2 sensor lean all point to one thing! Not enough fuel. Check fuel pressure.

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:thumbsup:Spot on Eaglemark...I would have never went back to this part of the engine. I had replaced the pressure regulator already and thought everything in that realm was good. Given your input, I took the upper manifold off and pulled the CPI unit out today. Got into the adventurous mode and took it all apart. Got everything cleaned out. Found two injectors that were possibly plugged up. Even though I got everything cleaned up and ready to put back in, I will never know if the work I did would have corrected the problem. During the reassembly, the pressure regulator retainer bracket mount did not like my over zealous tightening. I ended up installing a new CPI assy. After all was said and done, the fuel pressure went up to 62 psi when using the Relay bypass connector. ON pressure was 62 and off pressure was 54. I am confused about what the difference was between the various parts that were purchased but I guess it does not matter much at the moment. The truck is running and my son is happy once again. All the parts I purchased were BWD from advanced auto. Thanks again to everyone that offered up all the valuable info. I guess now I need a TunerPro for dummies book to read......

I never considered that it was running lean. I took advantage of the fact that it was running perfect until I repaired the fuel supply line leak. I was thinking that there were hidden faults that were unmasked when I did the fuel line repair. I have never worked with ODB1 maintenance so I did not know what to do. Once I got the TunerPro software, I was able to get a better idea of what was going on. I do still need to learn the basics for an ODB system. I guess I need a tuner for dummies book to get in the game. I will use your idea in the future though. I am a mechanic by hobby but my focus is in restorations of the classics.