86 f-150 wont start(seems to be when cold)

[iamlew]

I have an 86 f150 with a 302 EFI

So it started camping, woke up one morning and wouldnt start, tried for about 30 minutes and eventually it just started right up. after that the same thing would happen, nothing until i try 20-30 times and finally it would go(i'd have to hold the gas down about 1/4-1/2 way or it'd die, then after like 30 seconds it'd run smoothe)

Someone suggested to change the oxygen sensor, so i did that, still nothing (it started once then shut it off and started it when it was till warm worked fine.)

Code reader says

21
31

of course I can't start it so it's not testing at running temp.

Any ideas? Any way to heat things up to get it turning over (maybe one of the heaters for cold states)

I also replaced sillenoid, checked spark plugs, battery, changed dist cap/rotor. I found 3 brkoen vaccuum lines, and fixed 2 of them but the 3rd (coming off the egr valve) i cant find the other end to it anywhere.

[BroncoJoe19]

There should be a vacuum diagram under your hood or on your radiator support.

[BroncoJoe19]

So it looks like 21 is your temp sensor, and as you said, it wasn't running
and 31 has to do with your EGR and that doesn't have vacuum.

after you find and connect that other vacuum line, if it doesn't start then you have to go to the basics, see if it is getting fuel, assuming you have EFI you need 35 psi at the rail then check for spark,
let us know how you make out.
joe

[iamlew]

got it started again (seems like on the first attempt it trys to go and i have to pump the gas to get it going, if i miss the chance i have to wait an hour or so to try again.) So I warmed it up and got

31
10
61
31 I think the 10 31 61 are continuation right? so I dont worry about them or atleast for the time being?

how do i check the pressure at the fuel rail? this is the first vehicle ve had the pleasure of working on so I'm still a newb. Thanks for helping me out =)

that vaccuum was under the egr valve, not on it, i rechecked it had looked connected to it for somereason.

[BroncoJoe19]

Here is a listing of codes and when they may occur.
for example code 10 can only occur during KeyOnEngineRunning test.
Ford Fuel Injection » 2 Digit Self-test Codes 11-32

Two of the codes say that your voltage i slow, so I would check the connectors to them, and look at the battery cables, and grounds.

Ground number and locations in 1990 Bronco EVTM

G100 LH side of Radiator support
G101 RH side of Radiator support
G102 RH side of Radiator support
G103 LH rear side of engine, near knock sensor
G104 LH rear side of engine compartment, near electronic engine control (EEC) module, on the left fender close to the firewall
G105 LH Side of engine
G106 RH fender apron, near voltage regulator
G107 RH fender apron, at starter relay
G108 RH fender apron, at voltage regulator
G109 RH fender apron
G201 LH rear side of I/P (looking at the diagram it is at the bottom of the driver's side dash assembly. Screwed to the bottom edge, just to the left of the steering column. It is the ground for the instrument cluster)
G202 Behind RH cowl panel
G203 RH rear side of radiator support
G204 On steering column
G205 Behind Center of I/P (Dash), near speed control amplifier
G400 LH side of cargo area, near rear light assembly
G401 Below LH side of cargo area, near crossmember
G500 Inside driver's door, near left door speaker

[iamlew]

my battery cables are super oxidized (water getting under the hood in a puddle or river i think is whats causing it. Going to replace soon) I'm going to check my fuel pressure in a minute i just got a hold of a pressure gauge.

Fixed one of the vacuums, the second I cant figure out where it goes, the diagram shoes it going to EGR SOl V then to the ECV (i think) thats appears to be on the lef tof the EGR valve. I cant find any other broken lines or anything ti would even connect to. I got it running and it doesn't seem to suck or blow (put a buit of spit on it didn't do anything)

I might drive it to have my friend look at it since its warmed up i cant start it just fine. I'd like to have a mechanic run a diagnostic on it (and charge me out the ass is suppose) but im on the college budget right now.

I'll post back with any new findings. I'll see if I cant check those connections either. I found 9-10 exposed wires when i took off the uptake manifold and fixed those so I'm sure theres more wires that aren't in good shape.

[BroncoJoe19]

You'll need a fuel pressure test guage. You'll hook it up to a schraeder valve (looks like a bicycle valve). The fuel rail is about a 3/8" tube that runs along the top of the engine on the driver's side. The test guage will probably have directions with it.

Since this is your first truck to be working on, do yourself a favor and pick up a Haynes manual for your year. IT will walk you through testing all types of components, includeing the fuel system, and often includes helpful pictures. You can get them at any automotive parts store, for about $20.

[BroncoJoe19]

A good parts locator tool is to go to AutoZone.com - Get in the Zone!
enter the your truck year and engine etc, then use their search feature for the part, and locate it.
You have an EGR Vacuum Regulator (EVR) Solenoid it is located at the LH Rear of the engine on the coil support bracket. I mention that only becuase I do not know what EGR SOl V is.

[theoldwizard]

31 is PFE (pressure feedback EGR) or EVP (egr valve position) sensor signal low voltage.

61 is ECT (engine coolant temp) sensor signal low voltage

Either both of those sensors are bad, or there is a wiring problem to both of them. Using a volt meter, check for Vref (5 volts) on at least one pin on those sensors. Both of those errors codes can show up continuously or intermittent so don't replace the sensors until you do more checking (at least clear the error codes and see if they come back within a the first few minutes of operation).

A bad ECT will cause cold start problems because the processor does not know how much fuel to inject while cranking.

When ever replacing any sensor always, ALWAYS add a dab of dielectric grease on the pins. It is cheap insurance from intermittent !

You have got to find a vacuum diagram to show you the proper routing. If not you will have all sorts of problems with your EGR ! There should be one stuck under the hood. It was there when the truck left the factory.

[theoldwizard]

I found 9-10 exposed wires when i took off the uptake manifold and fixed those so I'm sure theres more wires that aren't in good shape.

Good wiring is an absolute must, if you ever want this thing to run reliably !

Originally Posted by iamlew

Fixed one of the vacuums, the second I cant figure out where it goes, the diagram showes it going to EGR SOl V then to the ECV (i think) thats appears to be on the left of the EGR valve. I cant find any other broken lines or anything to would even connect to. I got it running and it doesn't seem to suck or blow (put a bit of spit on it didn't do anything)

Newer vehicles all use DPFE to control the EGR valve. Older vehicles either use EGR VAC/VENT solenoids (a pair) or as Joe mentioned, and EGR Vacuum Regulator. Some more reading on EGR Systems: Operation and Diagnosis

Your spit test failed because the computer never "commands" EGR at closed throttle so no vacuum would ever go to the valve at idle.

Both of these systems control opening and closing the EGR valve. The computer knows how much EGR if flowing based on either the EGR Valve Position Sensor (if you have one it is that plastic thin on top of the EGR valve with wires coming out of it) or Pressure Feedback EGR sensor. Once the computer knows how much EGR you have flowing it can add more or take some away as required.

I'd like to have a mechanic run a diagnostic on it (and charge me out the ass is suppose) but im on the college budget right now.

Keep your money in your wallet. Your doing fine right here if you have the time !