My boss has an 02 that has been hard to start cold since I installed a used engine. I have checked the glow plug system every way that it can be checked and it is working properly. The glow plugs, uvc harness and valve cover gaskets have been replaced. I just got an autoenginuity scanner and now have the ability to check deeper. I just ran a scan on it and came up with a p 1316 which I think is related to the p 1273 1275 1276 and 1278 codes that also came up. When I ran a cylinder ballance test it shows 2,3 and 5 are weak. on the buzz test 1,3,5and 6 sound weak hot and 2,4,7 and 8 sound stronger. I will do a cold buzz test tomorrow to see how they sound. I also got a p 0476 which is probably a plugged back pressure sensor or tube. When trying to start it cold it sounds like it is trying to run on 1 or 2 cylinders. It will not start unless the block heater is plugged in even on a 90 degree day. Even with the block heater plugged in sometimes it has to be cranked 60 to 90 seconds (very bad for the starter and batteries). When it finally starts it is only running on 4 or 5 cylinders for the first minute or 2. It has 1 noticeable miss even when it warms up but does OK on the road. Can injectors or the idm cause such a hard start problem?

 

Whats the cranking high pressure oil at?

 

Around 2200 psi and the dwell is 15 to 22

 

Have you simply tried swapping a known good IDM into the truck?

I would venture a guess it's worn injectors or bad uvch...

 

I just got the autoenginuity and don't know anyone to borrow a the IDM from yet. The uvc harness set is new along with the valve cover gaskets and glow plugs.I did a buzz test cold today and the first time around only #2 sounded strong. All the rest were weak sounding. The second time 2 and 7 were strong but the rest were still weak. Also this time it only gave me p 1273 and 1278 and didn't have 1275 and 1276. these codes are for cyls 3,5,6 and 8 but the cyl contribution test says that 2,3 and 5 are low on power. We have been fighting the hard start problem for 2 years since I put the used engine in over my protest. The old engine had a bad HPOP and bad compression in #8 but it always started well either hot or cold. Cruising down the road the hpop would suddenly give only 500 psi and it would loose power until the truck was shut off and restarted. That was the reason for the engine change.

 

Sounds like you pulled the better motor out...

Sounds like an injector issue, but its hard to say with limited info. How many miles on the used motor?

 

I have no idea how many miles. The used engine is an e 99. I had to swap the turbo and pedestal intakes etc from the old one to the used one. When we got the engine I did a compression test on the ground and it had 2 cylinders that were about 100 pounds low and with a wet test they came up about 50. I told everyone involved I didn't like this one and the junkyard said the wet test showed valve problems that would clear up.(not) Wet test changes show ring problems but my boss listened to the junkyard and insisted that I put it in. I did another compression test when had the covers off to install the glow plugs that everyone told him needed replaced (again over my protest as I had tested each glow plug before putting them in when I installed the engine, all were good). The compressions this time ranged from a low of 360 to a high of 390. I don't like that much spread but it is within 10 % and over the 300 minimum that I have been told they need. When I did the buzz test tuesday night with a hot engine I got 4 injector open codes (p1273 1275 1276 and 1278) cyls 3,5,6 and 8 and a contribution test shows 2,3 and 5 low It would seem to me that an open injector wouldn't run at all yet # 8 shows good on the contribution test and # 2 shows bad even though it is good on the buzz test. I redid the buzz test wednesday morning cold and only had 2 injector open codes 1273 and 1278