just bought 1987 f150...have some questions

I just bought a 1987 f150 with 110000 OM(so the previous owner reported.)

When i got it like 2 weeks ago it was running great. The last couple days i've been having some problems though. The idle seems to be real rough. Also sometimes the truck will bog when accelerating as if it's not getting the correct amount of fuel. Also today i got to work and put the car into park. All the sudden, the engine starts revving VERY high. I put it into reverse and it went back to normal. Then back to park and it idled ok.

I'm not a huge mechanical guy, but my thoughts were:

-fuel pump(s)(the truck has 2 tanks one i know has a bad pump; The other one was supposidly fixed like 6 months prior to me buying it.
-Fuel injector(the previous owner told me 1987 was the first year they started putting fuel injection in these trucks.) i hope this is not the problem
-Some kind of throttle controlling element.
-I also read some other posts saying it could be a vacuum problem.

Thoughts? Advice? Suggestions? please help me! :D

thanks in advance.

-Prim

new development. Went to leave for work today. Car started after stalling twice upon ignition. I pull out of my apartment complex. At the intersection i hit the heat; Immediately the car died. Put it in park and turned the key. Nothing...didn't turn or anything.

Any insights? Is this consistant with valve leak or idle valve? Just seemed weird that it isn't turning over. The truck has never had any problems turning before.


thanks again


distressed.

-Prim

For the non-cranking problem - do you have access to a multimeter? If so then check the battery terminal voltage, which should be close to 12.6V with the vehicle at rest (i.e. ignition switched off, and not having made any attempts at cranking during the previous 15 minutes or so). Because it happened when you called for a little extra current (switched the heater on) I'm wondering if you have a charging problem and already had a somewhat flat battery. That's only a passing thought though and may not be the case.

When you switch the ignition to the Run position, do the gauges show any signs of life? Do the dashboard warning lamps illuminate? If not then check in the engine compartment fuse box for a blown main fuse, or fusible link.

Check your battery connections to ensure they are clean and secure - remove them from the terminals and clean the mating surfaces of terminals and connectors (I use a wire brush) and then reconnect them, preferably giving them a coating of petroleum jelly (Vaseline) or dielectric grease to inhibit future corrosion. Also, inspect the battery cables for signs of water ingress and corrosion. Follow the connections back from the negative terminal - you may have several on there - two in particular should be given special attention, and that's the heavy one which bolts to the engine block, and another fairly heavy one which will likely bolt to the firewall or fender - they should ideally be removed, cleaned, and a protective coating applied.

Because of the circumstances in which the vehicle failed, I don't think it's a problem specifically with your starter circuit so I won't go into that right now - I think it's a more general electrical problem.

The lights/gauges work fine. I had not noticed any problem with the battery previous either. So i'm thinking it's not a charging problem.

About to go check the cables and test the battery right now.

Also i have been told it could be the starter solinoid.(sp)?

Thanks again.

-Prim

Ok,so i just went and messed with it a bit with the bit-o-daylight i had. The truck turns over when i bypass the solenoid.I went and bought a new solenoid and installed it. Unfortunately it still doesn't turn at all. Also i checked all the dash fuses. all good.

So...i'm not sure where to go from here.....

suggestions? :)


thanks,

-Prim

Ok, so it cranks when you bypass the firewall solenoid, but a replacement solenoid has left you still with a no-crank situation. That means there's a problem with the 12V feed which energises the solenoid coil - the voltage is either low, or missing. I'm looking at a wiring diagram for the '87 to '89 F-Series, and the solenoid is fed thus: fuse (unspecified) to ignition switch 'Start' contacts, leaving there on a Red/Light Blue wire which goes to the Park/Neutral Position Switch (automatic) or the Clutch Interlock Switch (manual), leaving there still on a Red/Light Blue wire which leads to the firewall solenoid coil terminal - somewhere along that path there is a fault. That might be the ignition switch Start contacts, the transmission safety switch, or any of the wires and connectors along the path.

When you said "The truck turns over when i bypass the solenoid." - I'm not sure if you did that with the ignition off, in which case it would indeed just crank, or if you actually started the vehicle. It's easy enough to start it if you want to - just set the transmission to Park or Neutral (automatic) or Neutral (manual), apply the parking brake, switch ignition to the Run position, and then bridge the solenoid input and output terminals - the engine will then crank and run (which is possibly what you already did).

If the solenoid is awkward to reach, then you can connect a length of wire onto the solenoid coil terminal (that's the one with the Red/Light Blue wire) and route the other end of the wire over to the battery area. Strip a quarter inch of insulation from the end, and tie it to something. Then go through that same procedure - select Park or Neutral, apply parking brake, switch ignition to the 'Run' position, and then touch the bare end of that wire to the battery positive terminal - the engine will crank and run - as soon as it does, remove the wire from the battery terminal and tuck it safely out of the way.

You might find the problem by visual inspection, if you follow the red/light blue wire back towards the wiring harness - you might just get lucky and find a loose, dirty or corroded, or detached connector, but if not then you'll need to trace the circuit through using either a multimeter, 12V test lamp, or something called a 'self-powered test lamp'.

Tracing the voltage would be awkward, because of course that wire only has 12V when the ignition switch is held at the Start position, so instead of checking for voltage, I'd disconnect the battery negative terminal, set a multimeter to the resistance range and then simply test for continuity along the path - you could also do that with a self-powered test lamp, but a meter would be preferable.

If you go to the thread at the link below, follow the instructions in the first post, and select your year and model, then click on Repair Procedures - then Chassis Electrical - then Wiring Diagrams - you'll find the starter circuit on the diagram which is listed as: 'Fig 26: Chassis Wiring - 1987-89 F-Series and Bronco'

http://www.automotiveforums.com/vbulletin/showthread.php?t=890909

Let me know if you don't follow any of that, and let me know if you need any help with the fault-finding.

When i bypassed the solenoid(With the ignition in the start position) the car did crank, but did not start. I didn't allow it to try for very long for fear of doing damage to my starter. Should it have started if the electrical problem was the only thing. Previously to this the truck always started reliably.

I am not very experienced with electrical problems. Is there a fuse specifically for the solenoid/starter. I checked out all of the dash fuses. They all looked ok.

I'm going to talk to my nefew about the problem as well. maybe he'll be more comfortable with electrical problems; He's the one in the family that's the most mechanically inclined.

-Prim

Yes, if the ignition was in the Run position then the engine should have started when you bypassed the solenoid. That's if the problem with the feed to the solenoid was the only fault though - which I don't think it is. The problem with the solenoid feed would not have caused the two stalls prior to commencing the journey, and neither would it have caused the stall at the intersection.

My initial thoughts were that you didn't have a problem specifically with your starter circuit, and I still believe that to be the case now that you've confirmed that you did have the ignition switched on during cranking but it failed to start. One of the items which I listed as possibly being responsible for the missing feed to the solenoid, was the ignition switch Start contacts, but in view of the vehicle's general erratic behaviour - the poor idling - the unexplained stalling and now the sudden no-cranking, I'd say the ignition switch itself is prime suspect - not just specifically the Start contacts, but the whole switch (not the lock cylinder by the way - just the switch section).

If it isn't the ignition switch, then it could also be a bad feed from the battery into the switch - either low in voltage, or intermittent. Unfortunately, the electrical path for that isn't clear from the wiring diagram which I have, but you should check under the hood for a main fuse panel and ensure that it is securely mounted, and dry, and that the fuses themselves are securely inserted and that any adjacent connectors are firmly connected.

You asked about the fuse for the ignition switch Start contacts, which feed the solenoid coil - it isn't specified on the diagram but the feed will come from one of the high amperage fuses or fusible links in the engine compartment.

I'd head straight for the ignition switch, multimeter in hand, and check if 12V is arriving at the Start contacts - if it is, then I'd check if it is leaving the switch - if it's arriving but not leaving, then I'd replace the switch.

If on the other hand it isn't arriving at the switch then there would be no reason to replace it, and I'd turn my attention instead to the feed from battery to switch, via the engine compartment fuse panel.

So I think that will prove to be the main clue - does 12V arrive at the Start contacts, and then does it leave the Start contacts - and then proceed from there. I reckon your problem will almost certainly be confined to that small section of the electrical circuit - battery - to main fuse panel - to ignition switch.