95 gmc starting issues & more
 

I have a couple issues. First I can't build more than 5 psi on lift pump circuit and it decreases to 0 on acceleration. Changed pump. No change. Start up is rough and pukes blue smoke. Step on accelerator and chugs and glugs and pukes excessive blue smoke. I have discovered that unplugging the ECT improves start up. So much that I've wired in a switch to open the circuit. Any ideas? This truck has new injection pump, injectors, pmd, glow plugs and lift pump.

Has the electronic timing been properly set on the new IP?
TDCO relearn done and adjusted?

When starting do you engage the starter after the glow plug light goes out the first time like you are supposed to or wait for it to quit flashing?
Have you checked for power at all the glow plugs?
What brand glows were installed?

Where did the injectors come from?
Were they checked for proper pop pressure?

Adding a resistor will prevent the ECT code.
From a post by Theront:
Basic supplies:
SPDT switch
Resistor I had 5.56k ohm
wire to reach ECT sensor

Instructions:
solder resistor between pins A and C on the switch
solder yellow wire to sensor on B
solder yellow wire to ECM on A also

What you will have done is to put the switch in series with the yellow wire from the sensor. In position A the the computer sees the sensor normally. In position C the computer sees the sensor + resistor.

Racer 55, I had taken the truck to a shop in hopes that the pump would have been timed properly but I can't say for certain. Yes I attempt to start truck after first cycle of glow plugs. There is power going to my AC Delco plugs and the all test >2 ohms of resistance. Injectors came from local supplier. Ever checked them but truck only has 35 000 kms on new engine.

You could have fuel starvation caused by an aftermarket tank strainer on the sending unit giving poor fuel pressure.

An AC Delco LP from a 93 model year is the best stock LP available.

With the truck off I jump the LP relay and all I can produce is 5 psi at the fuel bleed tap that's mounted on the coolant manifold. It's dead headed so I tough that it should build up to max psi no matter if it is starving. Can the filter housing have some sort of failure? crack or something? I also installed a clear line on return from IP. No bubbles either. Thinking I should get it re timed.

Sounds like a weak LP,as mentioned AC Delco only from a 93 or aftermarket like FASS or AIRDOG.

A leak at the filter manager or anywhere else on the pressure side would make a puddle under the truck.

One other option is that the return line fitting/valve controls internal IP pressure and might be getting weak?

What type LP did you put on?

Getting it timed is a good move even if only for peace of mind.

LP is a Carter brand name from Bumper to Bumper. Phoned them and they said the specs are 9 psi and 25 ml per 15 sec.

As I said the fuel return valve might be defective,but as a rule aftermarket LP's are not very good replacements.

Most people find out that AC Delco for a 93 is the only way to go without spending a fortune.

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I should also note that fuel pressure from the WIF drain is unfiltered pressure-the IP will likely be seeing even less pressure.