Engine/Transmission (1998.5 - 2002) Hard starting and P1693 code

[tmacc]

The last couple of days the truck has been hard to start with it taking about 10 seconds of cranking to get it to catch. Fuel pressure is good, but sometime the lift pump will not continue to run if you bump it. Even if it does it, it seem to stop running during the cranking process. Maybe this is normal. I tried an old lift pump that I had laying around I got a P1693 code this morning, which is "DTC Detected in PCM/ECM or DTC Detected in ECM". Any help with trouble shooting this would be helpful.

Thanks

Tom

 

[JKreiss]

There's A LOT of good info here on this subject. Once it starts and runs a bit, shut it off and try to start it again, does it start right up? Does it idle rough once it finally does start? Any smoke (blue,white,gray) at start up? Start with the easiest things first, make sure your fuel filter is clean and the cap is on tight with no air getting in. Start from the front and work your way to the tank inspecting the fuel lines for leaks. My 99' did the same thing, had a fuel leak on the return line coming out of the block. Could be one of a few things but start simple first.

 

[tmacc]

No rough idle at all. No smoke of an kind. Just slow to catch. I did change the lift pump. I put in one that I had taken out last year that I thought was losing pressure. The pressure is better with the old one than the existing one. No leaks that I can see. I go over it tomorrow to see if there's something I missed.

I changed the 5 year old batteries thinking they were part of the problem. They were weak, but obviously not the problem. I hope it's not the VP$$ again. This one only got about 66K on it.

 

[npieske]

Similar thing happened to me. I replaced my vp44 from Midwest Diesel and put on a FASS fuel pump replacement/bypass kit. No problems since... . sorry for your troubles. Been there, spent that.

 

[JKreiss]

Try pulling the codes again tmacc. 66k isn't bad, my dad lost his at 48k so you just never know. Like npieske, Dad went with Midwest fuel injection and a FASS, all is well in 50k and counting. I'd do some some further trouble shooting though before i went with VP. I'm assuming once it fires up it can restart no problem or is it everytime? Does it only hard start after it sits overnight or only when hot? These can all be symptoms of other things as well. Try to see if there's another code with the 1693, there should be.

 

[tmacc]

Guess I was spoiled by getting 190K out of the first one. The truck starts slow every time. Runs fine once it does though. It does seem slightly more reluctant to start when it hot. It's marginally better since I put the other lift pump in it yesterday. I'll try to pull more codes this morning. Biggest issue is with work that we have going on it's 7 days a week and the uncertainty of the truck is a bummer.

 

[tmacc]

As of this afternoon, P 1693 is the only code and the truck definitely doesn't like hot weather.

 

[tmacc]

Weird day. After yesterday afternoon, when it took about 3 time before the truck would start, the truck has started like normal all day. One minor hiccup in that the fuel pressure fell from a steady 15 PSI at cruise to about 10-11 PSI for a half minute or so. Something's going on. Not sure what yet, but It's probably just a matter of time till the other shoe drops.

 

[tmacc]

Jeesh!!! This ranks up there with one of the most frustrating days of owning this truck.

SO! After looking at the diagnostic notes on Blue Chip Diesel's site and trading an email with Chip of same, I came to the conclusion that the computer on the VP44 was hosed and I got one from Industrial Injection in SLC since I could drive there to get it. I got my re-built turbo from them last winter and they are easy folks to deal with. After what seemed like a lot more difficult installation than the last time I replace the pump 5 years ago, I sort of fired it up. It started, but not a whole lot better than before when it was cold in the morning. I drove it about 15 miles to throughly warm it up, came home, turned it off and the same freakin' problem as before. Crank, Crank, Crank, before it starts. However, now I get a P0122 code along with the 1693. So I guess the APPS is defective. NOT a happy camper right now! :{

 

[FourBarR]

the comments about the vp-44 going out at low mileageie 48 and 66 k. glad its not my truck because I would not be mine for very long. My truck has just passed 558,000 kms( 347,000k) on the original vp-44. Running without any problems,never had start ,or drivability problems.

 

[Silver_Ram]

Didn't see what lift pump you are running, but a weird thing happened about 18 months ago. Used to be able to install a fresh VP44 & FASS HPFP and send the truck down the road. The boys at Bosch don't like FASS, Airdog, etc. I think they changed something on the VP44 computer.



Now if you add an upgraded lift pump to a VP44 truck, within a couple days - they will start having a a hard start hot problem. Update the ecm to Dodge's latest version, and the problem goes away. The new flash cuts out the lift pump during cranking.



From time to time, you will end up with multiple part replacements during a single episode. I have had a few APPS & ECM combos, VP44, lift pump & ECM. Sometimes if you let a problem go long enough you can cause damage to other pricey components.

 

[Nyoest]

Weak batteries and poor connections can cause all your symptoms. Been there done that And got the T shirt. They don't even have to be bad batteries just weak. Getting them tested and cleaning connections is about the cheapest thing you can do.

 

[tmacc]

Batteries were the first thing I changed out. I cleaned the post clamps as well. Although I have a FASS in the box, I still have a stock lift pump on it for now, but moved back by the tank where it's been for about 8 years.



The truck starts better, but still takes too long to start. Probably 2-3 seconds of cranking when it use to fire right up. I'll check the TPS next.

 

[Newf Limo]

sooooo. What was the fix?

I have been going through these threads trying to figure out what the problem with my truck is, and nothing ever seems to be posted about the final fix. Very frustrating.

 

[gtwitch]

Try Chips trouble shooting guide to check for air in the primary side (clear tygon tube under the windshield wiper) so you can see if there is air getting in the primary side before the VP. lHad thhis happen and plague me for about 6 months about 2 years ago and found the air leak at the filter top and fixed that and no problems since!

gtwitch in wyoming

 

[Newf Limo]

Thanks. Just ran through Doug's instructions from Blue Chip. Not good. When The truck runs, it is chugging and barely making 300 RPM. No throttle response whatsoever. I replaced the fuel filter, verified the lift pump is working and hot wired the injection pump. No change. You have to un-hot wire the pump to get the truck to shut off so I am pretty sure that the wiring was correct. So, it looks like I need to order a pump from Blue Chip.

Thanks gtwitch from Wyoming. One of my favorite states after Montana.