1.Lift pump test (http://dieselplace.com/forum/showthread.php?t=39350)- PASS. Service Engine Light - ON (BUT CLEARS IMMEDIATELY)
3.Model year 95
3a. Odometer reading 77000
3b. Miles on major engine components if been replaced 100 MI ON NEW IP BOUGHT FROM LOCAL STANADYNE DEALER. 2000 MI. ON NEW ALT.
4.Do you have any engine codes? YES.
5.If you do have engine codes - what are they? 18-35-54 (BUT CLEAR IMMED.)
6.Air Filter condition (GOOD, CLEAN)
7.Fuel filter condition (freshly changed)8.Condition of Battery terminal connections (cleaned and tightened)
8A.Known condition and age of the batteries. 2 NEW
9.Upon cold start, does the radiator hose get hard quickly? NO upon cold start, do you have excessive white smoke? no
11.Do you have excessive cranking time before the engine starts? NO
12.Have you used the block heater, and does this effect engine starting? NO
13.During hard acceleration, do you have excessive black smoke? NO
14.Do you have any unusual exhaust smoke issues? NO
15.Turbo check out (http://dieselplace.com/forum/showthread.php?t=39368)- PASS
16.Do you have an EGR (http://www.dieselplace.com/forum/autolink.php?id=42&script=showthread&forumid=21) on the engine? YES
17.Indicate if you know if it’s a 2500
18.Indicate fuel that you are using: NORMAL PUMP FUEL DIESEL
19.Are you using any fuel additives? WALMART POWER SER. BRAND (JUST STARTED LAST FULL TANK)
20.Please indicate geographic region you are in: HOUSTON, TEXAS AREA
21.Do you have any service history available that might pertain to the problem you are having? ORIG. OWNER INSTALLED PERFORMANCE CHIP WHICH I REPLACED WITH ORIG. OEM CHIP. I THINK THERE IS ALSO SOME SORT OF AFTER MARKET TRANNY CONTROLLER. AND DOWNPIPE.
22.Please indicate any modifications to the vehicle that might help us diagnose better. REMOVED SNORKLE - REMOVED PLENUM OBSTRUCTION - INSTALLED BOOST GAUGE - NEW LIFT PUMP - INSTALLED OPS BYPASS SWITCH ON INST, PNL. - NEW STANADYNE IP - RELOCATED PMD UNDER FRONT BUMPER (SOLDERED EXT. HARNESS) - NEW FILTER HARNESS FROM HEATH - NEW CRANK SENSOR
23.Upon unscrewing the fuel cap (http://dieselplace.com/forum/showthread.php?t=42338), do you have a large vacuum formed in the tank? YES, BUT SAME PROBLEM WITH NO CAP

TRUCK RUNS GOOD UNTIL I GET ON PEDAL, THEN STUMBLES AND DIES, ESPECIALLY WHEN TOWING TRAILER.

AFTER CLEANING ALL HARNESS CONNECTORS,TRUCK RAN GOOD UNTIL I TOWED TRAILER, NOW HAVE PROBLEMS WITHOUT TRAILER.

95 GMC SIERRA, 77K, DOWNPIPE, PERF. CHIP, BOOST GAUGE, OPS BYPASS SWITCH ON INST. PNL., LOW FUEL PRESS LIGHT ON INST PNL WITH PRESS SWITCH AFTER FILTER
2 NEW 9 IN. (2.5 IN. THICK FROM PARTZFINDER) COOLING FANS WITH THERMOSTAT AND SWITCH ON INST. PNL.



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17-18-54 indicate possible wiring\connector problem with the OS harness, could be back behind the Fuel Filter, where the engine harness joins the main harness in at least three connectors..

Also, try running without the OS filter - all three circuits are regulated +5v dependent.

Thanks GMTD. I will try to remove the harness filter tomorrow. Is this the same as the OS filter?

Also, I am getting DTC 35. Could this be a problem with the home made extension harness that I made for the new PMD?

Also, do you know of a shop in the Houston area who can check timing for me for a fee?? The local shop here in League City will not do it for me because I replaced the IP, not them. The local dealerships have hosed me on every occasion for the last 36 years, so I avoid them if possible.

Thanks again, Jim

Brian Alley is out in your neck-o'the-woods, Turbine Doc has the address and phone#

With all those OS DTC's, you can't really depend on a 35 or 36 event, so see if you can find what's causing them.

But do try it with the OS filter removed - I haven't run mine in a coon's age.

You used the IP harness that came with the new pump, right?