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Hard start and grey smoke after repair.

valyidol

Active Member
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Location
Russia, Moscow
SUBURBAN. Owner decided to do SWAP, remove 5.7 petrol engine, install 6.5 diesel. Diesel after repair. The cylinders are bored 0.5 mm. New pistons. The crankshaft is polished. New crankshaft bearings. New injector nozles. After engine repair the truck don't start 4 years. The owner asked me to start the diesel. I got a truck with a diesel under the hood but without engine wiring. I install 1995 engine wiring and PCM. The new STANADYNE PMD.
Now diesel is hard to start cold and hot. And has gray smoke cold and hot. Diesel runs smoothly. Now it is not possible to connect TECH. What could be the reasons? Timing? Bad injectors?
 
Wow. Choosing ds4 ramped up difficultly factor for sure! Well, guess they can pay you for their choice...

Grey smoke causes- air in fuel system get white to light grey. Cold cylinder temps- yes from timing is highly probable especially since the ds4 is in play. Getting it timed accurate is a simple MUST DO. Moisture (cracked head for instance) is usually white but it tiny amounts it will be grey. Burning oil is usually blue, but tiny amounts will cause light grey- which if the rings are not seated yet this can add to it. A compression test is a really good starting point for that avenue.
Unburned excess fuel is usually black, like when air filter is plugged. But unburned fuel is white like a cold morning start. So, when the JUST the right amount of unburned fuel gets through of black and white- you can get a grey. Depending how old the fuel is and if it has alcohols or cetane boosters in it when it was new can have an affect also. Drain the old fuel and use new fuel to eliminate any possible issue there.

So- identify what the smoke is not just by color. Smell the exhaust smoke. As mentioned get the clear ip return Line on there. Read the fuel pressure at the ip.
The beautiful thing about diesel diagnostics is, the same actions are taken to find the issues for 95% of problems. Do all the “Normal” tests and poet results.
 
After You get the hard to start and white smoke figured out, You`ll need to get the ALDL connector on there so You can get the timing properly set.
I hear the 95 is still running the OBD1 system so that will be the software from Leroy diesel and also a computer of sorts to read the software.
I`m sure that there still must be an ECM in the configuration being it is 95 wiring.
 
Now it is not possible to connect TECH.

Why not? If the ECM will not enter diagnostic mode and connect to the TECH you have serious problems. Last one I ran into that wouldn't read out codes was bad grounds. The other was a bad ECM.

This is quite the STUPID swap as shown by sitting four years. You may regret working on it: it will be a constant Pain In Your Ass! I would rip the ECM DS4 out of there and put a DB2 injection pump in. After all it will keep coming back to YOU for repairs.

You can tell by the sound if the timing is set close enough. So I wonder if there is gasoline in the fuel or another fuel problem. Maybe they did not drain the gasoline (petrol) before adding diesel? Inspect the fuel.

Do you know for sure the work and the quality of the work done to the engine?
 
Are your glow plugs working? I once swapped computers in a truck between an "F" vin truck and "S" vin truck to see what would happen. The glow plugs would not activate with the foreign computer...just thinking you should confirm activation of the glow plugs.
 
Are your glow plugs working? I once swapped computers in a truck between an "F" vin truck and "S" vin truck to see what would happen. The glow plugs would not activate with the foreign computer...just thinking you should confirm activation of the glow plugs.
I warmed the glow plugs by hand
 
Why not? If the ECM will not enter diagnostic mode and connect to the TECH you have serious problems. Last one I ran into that wouldn't read out codes was bad grounds. The other was a bad ECM.

This is quite the STUPID swap as shown by sitting four years. You may regret working on it: it will be a constant Pain In Your Ass! I would rip the ECM DS4 out of there and put a DB2 injection pump in. After all it will keep coming back to YOU for repairs.

You can tell by the sound if the timing is set close enough. So I wonder if there is gasoline in the fuel or another fuel problem. Maybe they did not drain the gasoline (petrol) before adding diesel? Inspect the fuel.

Do you know for sure the work and the quality of the work done to the engine?
Now I don't have TECH. It was stolen. Fuel is new. I hope the work and the quality of the work done to the engine is good. Engine runs smoothly without misfires
 
Smokes from both exhaust manifolds.. So there are no mechanical reasons. Remaining fuel, bad ECM, air in fuel and injection timing. What else? ...
 
IMO, the suburban just needs to be driven for some miles/km (at least 100 or so) to get all the kinks out of the engine.
 
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