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6.5L No Start and scanner says it does not have a ecm

C

C F Industries

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Location
Gonzales La.
I have a 94 6.5l and it will start if we pull the truck, but it has no power. I tried to connect my Snap-On scanner to it and it tells me that the truck does not have a ecm except for the trans. Well this truck it a stick! So I saw all of the posts about the grounds and I took them apart and cleaned them. It made no difference. Is there a fuse or relay for the ecm? Where is it? It acts as though it is not getting fuel. any help would be great.
My experience is very limited with these trucks.
 
Hello, and welcome, what model truck is this, in 94 there were commercial trucks and vans available with mechanical injection without a PCM. Is this a passenger truck with electronic fuel injection, because if the PCM wasnt working it would never start regardless of what you do.
 
Welcome!!!

May be the scanner is not designed or have interface for OBD-I. Which is in a 94.

All you need is a paper clip to read the code.

Does it at least have electric??? or cranking but no start??? Needs a little detail.
 
Snap on scan tools especially a MT2500 don't work on a 94-95 chevy diesels. A Tech1 Or Tech 2 or GMTDscantech software with a laptop computer and obd1 connecting cable will be able to read the ecm codes and give sensor readings. If your truck is actually a 93 there is no ecm or tcm if it is a manual transmission.
Check all fuses. The ecm has 2 power supplies.
Something very helpful is to run the VIN on this vin decoder. http://www.compnine.com/vid.php
 
I'd bet the harness to the IP is chaffed under the intake and blew the ecm fuse. Happened on my 95. If you have No SES light and no glow plug light chances are that is the right direction. Can't remember where my fuse was but I think there is a fuse block under the hood as well as the dash.
 
It starts when you push start it?
Do you get a glow plug light when you turn the key?
What is the cranking RPM? - it must be over 100 RPM to start.
What is the fuel 'lift pump' pressure at the water drain with the engine running?
Get and post a picture of the Injection pump top. If it has 3 wires to it and a throttle/cruise cable you do not have an ECM.
 
Thanks for the info guys, Sorry I didn't answer sooner, but I was working out of town. ............. Ok where to start.
The engine spins and once in while it hits but will not start. I have fuel through the bleeder with the key on and while cranking.
I can see the ecm in the rt side of the dash. I don't remember which pins to jump to get it to flash a code, also I'll need a code chart to know what the code means.
My scanner is supposed to be able to read all obd 1 from 83 on and all obd 2 through 2009. I gave my mt2500 scanner away when I bought the latest thing from Snappy.
I will check the fuses and the harness.
This truck is a C2500 with a 6.5l and manual tranny.

I'll try to get the codes tomorrow nite and check the fuses. Thanks.
 
The 94-94 6.5 diesels are unique. Snap on never did figure out how to get accurate readings on them. They are different from other obd1 cars and trucks.
 
First, welcome here.

Second, take a few minutes to fill out your signature. Click on the signature link in mine.

Third, the answers you seek are in the 6.5 Technical library. It's in my signature, too.

Or, you can click here to get to the library, then scroll down to D (for Diagnostic Trouble Codes, or DTC), and you'll find a list and a tutorial on how to use your paper clip to read the codes.

The ALDL port is under your steering wheel.
 
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Well I checked the fuses and found the ecm fuse blown. I replaced the fuse and jumped the aldl. I got a code 29 for the glow plug controller not working. I removed the jumper and tried to start the truck, it spins but does not start. I checked the code again and still had just the code 29. Will this engine start in 98 degree weather with out the glow plugs?
 
Most of mine won't start cold without the glow plugs. Once the engine has run they should start without them.
You can bypass the glow plug controller with jumper cables connecting the big terminals together. The glows drawv100 amps so a jumper wire would have to be large and easy to disconnect after it starts.
Whatever you do, do not use ether or starting fluid. A shot or 2 of wd40 into the intake after the air filter won't hurt and will help start.
Glow plug controller failure is fairly common. There is many fusible links and fusible wire in the glow system.
 
You could also plug it in overnight and try to start it again tomorrow. That will, at least, give it a better chance of starting without the glows working properly. If it does start that way, you have narrowed the problem to the glow system rather than the IP/ECM/fuel system problems.
 
Depends on the 6.5 and injector condition. Mine was impossible to start in 105 degree weather without glows. Till I replaced sticking injectors. Really need glows when 'cold' to get it to start. Careful the amount of time you jump the controller esp. with 9G factory plugs that do not self regulate.
 
WarWagon said:
Depends on the 6.5 and injector condition. Mine was impossible to start in 105 degree weather without glows. Till I replaced sticking injectors. Really need glows when 'cold' to get it to start. Careful the amount of time you jump the controller esp. with 9G factory plugs that do not self regulate.
Click to expand...

Great point, WW ... bad glows are the kiss of death to many of these 6.5s ... if they have good compression, good spray, and are turning over fast enough, then yeah, they'll start without glows, but it's one piece of the puzzle, for sure.
 
Wow, you guys are a great help. I not very familiar with these engines, I do a lot of 7.3 and 6.0 work for people though. So I'll try to bleed the injectors to be sure that the fuel pump is opening them. What should the ohms reading be on a good glow plug?
 
I got the feeling that the GP or the controller or both are bad.

The ohm should be small. The best way is to remove 1 and see it.
If it is a ACDelco 9G, replace it anyway before it start swelling and you cannot take it out.
Get Bosch Duraterms from RockAuto. It is only around $60 shipped, I just posted a code in the Deal section here.

The GP controller is not too expensive either, around $50 at OR or AZ or Napa.

Also check the other fuses and all the electricals like batteries, starter, alternator, connectors, grounds, etc.
 
I took all of the grounds loose and cleaned them and made sure that they were tight after I saw what some others had posted about the trouble that they cause with this truck. I'll get the gp and controller out tomorrow and test them. After that is working I'll try getting her started again. I think I may pull the intake to check the wiring for chafing because I have not seen anything else that was obvious that could have blown the ecm fuse.
 
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