Hard start after IP change - UPDATE

[DennisG01]

Just had my IP replaced under warranty (90,000 miles). Now, when the truck is cold (sitting) - not neccessarily the weather, although it is slightly worse with colder weather - it is hard to start. Before the IP change it would fire right up in only a second (other than the times when the IP was acting up). Now it takes a good 3 - 5 seconds while it stumbles and tries to start and there is a lot of gray and white smoke. Once the truck has been running for about 15 to 20 minutes, it will restart right back up. Also, once the truck has started, it runs fine. I don't think it is the glow plugs - they are new last year, I plugged it in overnight once, and I kept it in the garage once - no difference with starting.

The dealer thought it was because I was still running on summer fuel. So, I ran that tank just about completely empty and filled up with winterized. I've now put 125 miles on the truck and no difference.

I plan on taking it back to the dealer, but I'd like to know what some of you think? As I said above, it always started right up before the IP change (other than when the IP was acting up)

[ 11-20-2005, 04:21 PM: Message edited by: Dennis Galligani ]

[Kennedy]

Glow plugs are the first thing that I look at when working on cold starting issues.

[DennisG01]

That was my initial thought, as well. However:

I am getting power during the glow cycle to the plugs (I only checked the driver's side)

It started hard on a 70* day

I tried using the block heater over nite (only went down to about 40*) and it still started hard

I also tried leaving it my garage (about 55*) over nite and it still started hard

[landrea]

What about the ip timing?Seems odd it acted up after pump replaced,could the timing be off?

[DennisG01]

I think that will be my next step - I just called the dealer and I'm going to stop by this afternoon and have them check the IP timing.

How long should it take the dealer to check the timing?

[JohnC]

Originally posted by Dennis Galligani:
How long should it take the dealer to check the timing? 30 seconds. Longest part is waiting for the Tech II to boot up...

[DennisG01]

That's kind of what I thought, John. Wanna know what the service manager was trying to tell me over the phone? We'll see what actually transpires when I go there this afternoon...

[DennisG01]

You guys will love this!

I called the Service Manager of the GMC dealer that installed my pump. I asked him if I could come by (yesterday afternoon) to have the IP timing checked. He said "well, that's not something we can do in just 5 minutes". I said "really? I thought you just needed to hook-up the scan tool and get to the right screen?" He said "well, it's more involved than that. But, come by and we can atleast check for codes".

So I get over there and the technician plugs in the scanner, checks for codes - nothing. Of course, he goes right on to check the timing. Comes up with the screen that says "desired: 0.0 - actual: 3.5 (ranged from 2.9 to 4.0)". I said "OK, but how about TDC Offset, I understand that GM specs are from -.25 to -.75" Here's the punch line: He said "I have no idea what you are talking about - someone has given you wrong information".

Now, I'm not a mechanic (far from it), and supposedly I'm in the presence of greatness with this Factory Trained GM Technician who is also the dealership's top diesel tech - but come on!!! You know?

[DennisG01]

OK, first the TDC offset is -.26 (took it to a local garage). I don't know how the GM Tech got it within specs when he had no idea what TDC offset was!

I just tested all 8 glow plugs for resistance. 5 OF THEM ARE BAD (John Kennedy, you were right)! These plugs were new as of January '05 from SS Diesel Supply (2 year warranty). But, the truck was starting just fine before I took it to GMC for IP replacement. Is there any way that the dealer could have zapped 5 glow plugs during an IP replacement?