Converted the 1998 S10 from SCPI to MFI fuel injection today. I went to turn it over to test the work and the engined crank for a split second and stopped.

The electric appears to be working- the radio and blower motor are working. The fuel gauge and temperature gauges have swung all the way to the fight, showing over filled fuel and temp way past overheating.

The only thing I can think of is I "vapor locked" the engine when I cleaned the carbon of the upper intake manifold (wear the injectors plug in) with a can of seafoam and carb cleaner. Much of it drained into the manifold- likely a can worth of seafoam.

Any thoughts? I sense I can take out the plugs and try and turn over, but wanted some input from forum members- maybe I have another issue.

You mean you hydrolocked it cleaning it? Yes, very possible. Pull all the plugs, press the accelerator to the floor so the PCM sees at least 95% throttle(this turns the injectors off) and crank away for about 30 seconds. Reinstall plugs, restart. Vrooom.

Thanks Mike, will try it in about an hour....

Pulled the plugs, turned it over for 30 seconds, put in new plugs and tried to start it. The hydrolock problem has gone away.

Now it just turns over, no signs of it wanting to fire. I thought I caught the problem, I pulled the wire from the coil to the distributor cap to prevent the spark plug wires from getting power during the hydrolock cleaning. Plugged the coil wire back together- same problem.

I don't think the new plugs are fowl. Went back and checked all the connectors that were separated when I pulled the upper manifold, everything looks connected.... The only issue I can see is the temp gauge is showing well past 250 degrees. Maybe a pinched wire?

Time to check for spark.....

how about the engine ground?clean and tight?

Justin,

I am on my way to Advance Auto to pickup a inline spark tester. Other than the coolant temperature gauge, the rest of the instrument cluster electronics are functioning. Why do you think I may have an engine ground issue?

the sensor for the temp, and the coil, and a bunch of other things ground through the engine ground.

Just tested for spark- looks ok. I was guessing cold be a coil, or even a crankshaft position sensor. I smell fuel and have a newer Delphi fuel pump.....

Back to the drawing board.

Had a new OEM coil, went ahead and installed it, and the S10 started up. I drove the S10 30 miles and no issues.

My concern is something Justin mentioned. When the truck started, the temp gauge showed normal. When the truck would not start the temp gauge read well past the overheating point. Justin mentioned a bad engine ground can cause gauges to read like this.

Heck, I might replace the crank position sensor, I have a new one laying around, just start replacing ignition related items so it can make troubleshooting of a intermittent problem a little easier...

i would clean the ends of the big cables, but i wouldnt be replacing stuff that works