1987 F150 (5.0L 302 V8) two problems - rough idle + now won't crank
09-20-2011, 01:04 AM
#21
Well, I thoroughly cleaned the area in which the negative battery terminal is grounded, replaced the old negative battery cable, properly seated and installed it, and still...won't crank. I can hear it thump, but that's it. After a couple of attempts and thumps, I hopped out, and looked around at the battery, solenoid, and starter. The battery terminals were warm, as was the solenoid, and the cable from the solenoid to the starter itself.
I would assume this means that power is getting from the battery, through the solenoid, and to the starter, and either the starter is bad (blown by the old bad ground, or perhaps half-dead out of the box from Advance Auto?), is incorrectly seated/installed (but then, wouldn't it move MORE freely, not less?), or the flexplate isn't moving freely (which I imagine would be quite a bad thing, but I think is unlikely given that the engine was running before I turned it off the other day, and tried to crank it up again later to no avail).
Once I've removed the starter, is there a way I can manually move the flexplate to verify it isn't seized, etc? Is there a way I can manually move the starter as well?
As for the rough idle issues, is it possible it's a MAP sensor problem? Aside from unplugging the wire to it during operation and observing behavior, is there a specific way I should test that?
I would assume this means that power is getting from the battery, through the solenoid, and to the starter, and either the starter is bad (blown by the old bad ground, or perhaps half-dead out of the box from Advance Auto?), is incorrectly seated/installed (but then, wouldn't it move MORE freely, not less?), or the flexplate isn't moving freely (which I imagine would be quite a bad thing, but I think is unlikely given that the engine was running before I turned it off the other day, and tried to crank it up again later to no avail).
Once I've removed the starter, is there a way I can manually move the flexplate to verify it isn't seized, etc? Is there a way I can manually move the starter as well?
As for the rough idle issues, is it possible it's a MAP sensor problem? Aside from unplugging the wire to it during operation and observing behavior, is there a specific way I should test that?
Last edited by LBGSHI; 09-20-2011 at 01:06 AM.
09-20-2011, 12:54 PM
#26
Old Bastard
If it is a manual the transmission will need to be in neutral. There are 100 different reasons why your engine might sieze. I have seen a cylinder fill up with gas and cause an engine to hydraulic lock. When we pulled the plugs gas ran out.
09-22-2011, 11:44 AM
#27
Member
It thumps, doesn't turn, and the cables were hot? Id say your starter is screwed from all the times you tried to start it with low voltage, bad ground, etc. Remanufactured starters from Advance Auto arent the best built anyway. Try putting your old starter back in it and see if it works. I doubt the engine is seized considering it ran not more than a week ago, unless fluid got stuck inside the piston in which case you can just pull the spark plugs, clean them off and spin the engine over to spray the fluid out. The crankshaft pullry should have a 15/16 bolt that you can put a break bar on to turn the engine. If the engine turns freely, your starter is probably bad
09-22-2011, 07:17 PM
#28
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Hello,
You may have a flywheel band worn out. You can rock it in gear and get it to move until the starter gets good teeth, it may crank then.
I have a 1987 f150 xlt with a 302 and had to replace mine last year.
You may have a flywheel band worn out. You can rock it in gear and get it to move until the starter gets good teeth, it may crank then.
I have a 1987 f150 xlt with a 302 and had to replace mine last year.
09-22-2011, 10:43 PM
#29
I took the new starter back to Advance Auto, they tested it, and verified it was bad. It even smoked when they tried to test it. They gave me another new starter, and after installing that one, the engine cranked right up. So either I got a bad starter right out of the box, or my previous bad ground situation fried it. In any case, I've completely replaced everything in the starting system (starter, cable from starter to solenoid, solenoid, cable from solenoid to battery, battery, cable from battery to ground on engine), and ensured clean, shiny, tight connections between every component, so hopefully the issue stays resolved.
Now back to figuring out the idle issues.
I found a vacuum hose that was actually two vacuum hoses, with a plastic tube connecting them internally, and it wasn't very well seated. I replaced it with a single hose of the proper length. I've also picked up a new MAP sensor and a pre-cat O2 sensor, which I'll install tomorrow. I'll report back with results.
You called it 
Now back to figuring out the idle issues.
I found a vacuum hose that was actually two vacuum hoses, with a plastic tube connecting them internally, and it wasn't very well seated. I replaced it with a single hose of the proper length. I've also picked up a new MAP sensor and a pre-cat O2 sensor, which I'll install tomorrow. I'll report back with results.
Originally Posted by 351W1085
It thumps, doesn't turn, and the cables were hot? Id say your starter is screwed from all the times you tried to start it with low voltage, bad ground, etc. Remanufactured starters from Advance Auto arent the best built anyway. Try putting your old starter back in it and see if it works. I doubt the engine is seized considering it ran not more than a week ago, unless fluid got stuck inside the piston in which case you can just pull the spark plugs, clean them off and spin the engine over to spray the fluid out. The crankshaft pullry should have a 15/16 bolt that you can put a break bar on to turn the engine. If the engine turns freely, your starter is probably bad
09-23-2011, 04:20 AM
#30
