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94 k1500 350 hard starting

11-13-2010, 05:50 PM
I have a 94 k1500 with a 350 in it. It has been running pretty good until this week. Last week I put a new gas tank, sender and fuel pump in it. I also replaced the fuel and return lines as well as the fuel filter. It already had new plugs, distributor cap, rotor and wires. Last year I replaced the coolant temp sender and the pressure regulator. I check all the vacuum lines and have cleaned and oiled the K&N air filter. Since the weather has been getting colder I noticed that it hasn't been going up to high idle on start when cold and has started chugging so I have to push the gas pedel down and get the RPMs up to over 2000 for a bit so that I can get it to run. Now today it got very hard to start when warm. I have to give it gas in order to get it to start. After it start it runs great plenty of power and idles nice and smooth. This truck never had a problem starting and I never had to give it gas to get it to start ever. I'm not sure what is going on any ideas would be greatly appreciated. I'm wondering if the new fuel pump my be fubar. Or is it just a coincedence. What kind of adaper do I have to build in order to check the pressure? The fuel pressure gauge I have screws on to a scrader valve.

11-14-2010, 09:16 AM
The first fuel pressure gage I ever had, I made it. I used a gage from old cutting rig, torch, that I didn't use any more. Screwed the gage into a pipe-tee, used hose fittings in each end of pipe-tee. It just depends on where your going to tee in, have to use your own initiative. The one I have was for teeing into the supply line if no schrader valve, still works. With tbi, I usually tee-in at the fuel filter, in place of the fuel filter. The hoses on the gage will push up over a flare on a steel line. I didn't think to look at your filter, a quick connect fitting is a different issue. You could also check fuel volumn at fuel return line.

11-14-2010, 05:18 PM
Here is what I found today.

Broken ground that went to 2 of the sensors. I replaced the terminal end and cleaned it. I went and bought a Throttle Body Rebuild Kit and replaced all the gaskets and cleaned the injectors.
I measured the resistance of the Coolant Senso and it is inline with the temp.

The truck runs much better and I don't have to give it gas to get it to start.

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