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94 6.5 won't start. After I installed new lift pump.

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Bigben92

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Caddo mills TX
Hello y'all. I'm new to this site. And I'm really needing some help! I recently bought a 94 1 ton Chevrolet truck with the 6.5 turbo diesel when I bought it it was very slow to start maybe 30 seconds of turning over before it would. And it had very little power. Throttle had very little response I could floor it from a dead stop and it would probably take 45 seconds to hit 20 miles per hour once it got above 15 to 20 miles per hour it would have run pretty decent had to let off the gas for it to shift and wouldn't go above 65 or so. The truck has a brand new injector pump I installed the new lift pump a new PMD new App. *where the real trouble starts.* I tested the lift pump by starting the truck and opening the T valve to see if you would come out or if it would die well fuel didn't come out and it died so I replace the lift pump I have not been able to start the truck since I have tried to bleed the air off of it I'm getting fuel to my IP but not to my injectors. I'm at a total loss any help would be much appreciated
 
ak diesel driver said:
the 94 and 95 won't run the LP until the oil pressure comes up. You'll need to jumper the LP to get it to rum to bleed the system properly. A good upgrade is to put the LP on a relay and even better is to add the LP prime during WTS
Click to expand...


I have my LP on a relay now. I can manually engage it I have fuel at my fuel filter and at my injection pump but none at my injectors. Any idea what that could be?
 
So the truck ran (poorly) until the lift pump..?.
Now it will not even start.

Did you do ANYTHING else since it wouldn't start? Unplug and plug back in pmd? (Not saying do it now.)

How exactly did you bleed the air out of the system?

Are there any codes, and if so were they there before the LP swap?

What rpm is the engine turning at?
 
Sorry if my first post was confusing I used voice text didn't realize how bad it ended up. So when I bought the truck it ran poorly. Took a long time to start and had very little power. In the process of trying to fix it I tested the LP by jumping it on the fire wall. Didn't work. So I started the truck and opened t valve... No fuel came out and truck died quickly. So I purchased a new LP and installed it. And bled the lines by jumping the LP *I can hear it engage now* I opened the fuel filter and its pumping plenty of fuel to it so I tried starting it and it just turns over doesn't even seem to be getting any kind of fire. *or how ever I should say that* so I loosened the front injector on the driver side of the motor and jumped LP again but no fuel at injector so I back Traced to the IP and I have plenty of fuel going into the IP but none coming from it. I backed off 3 injectors and tried the same process on them but no fuel on any of them.
I'm very confused about it . Any and all help is much appreciated.
 
The first two things to work out on 6.5's are Grounds and Air In Fuel. The ground by the trans dipstick (ECM ground) needs to be taken apart and cleaned as a visual won't do. You have a PMD - is it on a cheap china extension harness? Where is it located?

When starting the 6.5 IDI diesel it's best to keep a AAA membership in mind. It's either going to start in a reasonable time or it's not going to start until it's fixed. Tow it. Further attempts are going to simply drain the batteries and melt the starter down. 30 second cranking time with 2 min or longer cool down time is the only way to start one. Any longer cranking bursts will melt the 10 HP starter.

The cranking RPM after the above hard starting times is suspect as other members asked about. Diesels need RPM to start. The 6.5 will not slowly spin over and start like a gas engine. You need 100 RPM min cold to start and 150 RPM hot. Our starters can loose 1 brush etc. and still spin at a slower speed that makes starting almost impossible.1 bad battery or connection will also slow cranking speed.

This is how it should sound for cranking speed. You can tell by ear if it's going slower...


Not starting now and runs poorly in the past has a fuel issue written all over it. Have you pulled the inlet hose off the IP to make sure fuel is getting to the IP? Add a clear return line on the ip to look for air. Fuel filter age? Jumper the lift pump on when cranking. It won't hurt anything to stay running.

Any codes?

After you are sure there is fuel to the IP here is a heavy duty guide to sort through and make sure the PMD is working:
http://www.thetruckstop.us/forum/th...-5-db2-5-7l-info-online-from-stanadyne.26581/

Quick and dirty to see if the ECM is even getting power: Do you get a SES and STS light during the bulb check?

Most of us have a spare PMD around.
 
On mine the lift pump wouldn't push through the ip with the truck not running. I had to crack open the injector lines while somebody was turning it over.
 
You said it has a new injector pump. Are you sure it was installed and timed correctly? Of course if you were getting fuel it would be smoking timed correctly or not. My vote is going to be on you getting the air all out. Jumper that lift pump and crack the clamps on the fuel lines before and after the filter. Once those are pushing fuel and no air bubbles it should be just a little cranking to smoke time.
 
Thank you guys for all your input! I really appreciate it. Sorry it took so long to reply I was out of town for the weekend.

So GOOD NEWS. I GOT IT STARTED. I DIDN'T DO ANYTHING DIFFERENT OTHER THAN PRAY. LOL I'M ASSUMING IT JUST FINALLY GOT ALL THE AIR OUT OF THE SYSTEM. But I'm still having a issue with it not having much power. It takes off from zero much better. But does not have enough power to shift without letting off of the when RPMs are high and then reapplying... I got 2 engine codes. I'm hoping y'all can help me with.


#1- code 18 - pump cam reference pulse error

#2- code 35- injection pulse width error

Any ideas?
 
consaka said:
You said it has a new injector pump. Are you sure it was installed and timed correctly? Of course if you were getting fuel it would be smoking timed correctly or not. My vote is going to be on you getting the air all out. Jumper that lift pump and crack the clamps on the fuel lines before and after the filter. Once those are pushing fuel and no air bubbles it should be just a little cranking to smoke time.
Click to expand...

The IP was installed by a local mechanic shop. A few weeks before I bought it. So I'm not sure honestly. I'm assuming it was done right but I'm not sure how to tell
 
Again: Where is the PMD? aka Pump Mounted Driver clicky link to what it be. Still on the pump? Did you check the grounds? Have you put a clear return line on the IP to look for air? The GM manual says to start with looking for air in the fuel system for a reason! In context of the codes it's because air in fuel can foam and mess up the "readings" the ECM gets from the IP.

The obvious as you just got it: What do the fuel filter and air filters look like?

Sounds like the PO gave up and didn't have a competent shop working on it: avoid that shop at all costs!!!
 
Okay guys so my truck has been in the shop for 7 weeks. Local diesel mechanic everybody says is the best. He said my ECM prom is bad. He figured it out 3 weeks ago. But no luck finding a ECM prom anywhere. Other that a 400$ after market. I've put a ton of money in this truck and really want to get it running right! It's not drivable won't go over about 35 mph... Does ANYONE KNOW WHERE I CAN GET A ECM PROM.??? PLEASE HELP. my truck is a 94 6.5 auto 2wd 2500
 
Get the number off the old PROM , have a dealer put it on locate . Should be discontinued but it might say where in the US one is in stock . Fleabay has one but it is for a stick .
 
Check this out , Norfolk Va on Craigslist . Parting out a 94 Suburban 6.5 auto with 4 miles on it . GM test vehicle ? Ad 6192443918 ECM $90
 
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