Hey guys. My 86 5.0 EFI won't start. I drove home from work in it and it died as I was pulling into my parking spot at home. It had been having trouble idling down and dying at red lights or in parking lots at real low speeds, usually once per drive or so. After it died at home I let it cool down and tried to restart it. But it would only crank without coughing or anything else. When it cranked it sounded different than usual, kinda like the starter was spinning but not engaging. I pulled the starter and had AZ bench test it. It failed, so i replaced it. With the new starter on the truck sounds different still. Same kind of sound. The starter is engaging and spinning the motor. I spent yesterday in the heat troubleshooting, here's what i've got.

SPARK- I have it. Nice healthy spark at all plugs. All the plugs were dry when I pulled them after cranking.

FUEL- I get fuel to the rail, but not enough. The low pressure pump in the front tank is dead, so it only has the high pressure pump doing the work. I suspect it's been driving that way for a little while now. Probably lean the whole time. However, I tried to spray starter fluid in the intake, just to get it to cough. It would not cough at all.

COMPRESSION- I haven't done a compression test yet, its damn hot outside.

CODES- I get a code 83- EGR control solenoid And a code 22- MAP sensor out of range. I replaced both my EGR and MAP sensor within the last couple years.

I really suspected the low fuel flow to be the problem, til I tried starter fluid. It didn't even hint at trying to start. And the low fuel flow doesn't explain the sudden change in sound while cranking. Neither of the codes seem relevant. Can the MAP sensor cause a no start? I'm not sure where to go from here. I have to work today, but I can mess with it all day tomorrow. Any insight would be great. Thanks fellas.

 

The map sensor is a important sensor. I would investigate why it's giving you that code.

 

I put a new map sensor on with no change. The line running from it to the manifold is good and the manifold port is clear. I didn't figure the sensor was it though. It should try to start on starter fluid even with a bad map. It's come down to timing or compression i believe. Nobody loans timing lights, so guess ill do a compression check.

 

No compression anywhere. And i was hoping for a free fix. What do you think, timing chain broke? Should i start looking for a hole in the block somewhere?

 

Does the rotor under the distributor cap turn when the starter motor turns the engine over?

 

Yes it does.

 

Then the chain isn't broken... but it could have slipped... but you should still get compression.

Removing the timing case cover and taking a look might not be a bad thing to do, I think I'd first remove a valve cover and watch the valves as the starter motor turns it over, see if the valves seem to be operating.

 

I have also seen pictures of flexplates that have sheared off the back of the crankshaft.

 

Well... That sounds like a job for future me. Thanks for the help.

 

On a side note, thanks for the help so far everyone. Very appreciative of the brainstorming that's going on.

 

Yup. Got em. Just trying to figure out how to get at these donut gaskets so I can get it all back together.

 

Who are you talking to? And, about what? This is alhauger's thread from over three months ago about his no-start problems....

 

No idea how that happened. Got....cross-threaded