krashink

hey guys 86 f150 fuel injected here, pulled the 5L out replaced all seals put it back after a vigours cleaning and a paint job. She doesnt want to start fuel pressure is 40psi,new cap roter wires and plugs. getting spark but its orange, kinda on the weak side if ya ask me ....its gotta be blue, means its hot. the solenoid fried and blew up the battery....not sure why this happened...any ideas??....i was thinking there maybe is a short or somthing in the harness.. not sure though...but i was thinking that damn near everything is fused, pretty much except the starter....could the starter be at fault??.....what else could make the solenoid fuse its self together???
I have tried everything even checked to make sure its all top dead center....replaced the coil as well.....
What else could actually be going on in this situation???
if anyone knows the answer....would be greatly appreciated.

Thanks in advance,

Krashink

wde3477

For the solenoid - starter is a possibility, easy enough to pull and have tested. I'd suspect that with the trouble you're having with starting, the solenoid may have just overheated to failure under extended loading, particularly if the contacts weren't in great shape to begin with.

For the no-start - need more specifics on what all was removed and what work was done. Do you smell gas or are the plugs wet after the extended starting attempts - is fuel getting into the cylinders? Is the motor even trying to fire/backfire, or is it just a dead turnover? All harnesses snapped securely together, etc.?

Fuel, spark, timing - has to be one of them.

krashink

Thanks dude.

When I try to turn it over she has spark, but the spark looks a lil weak to me (orange) when i pull the plugs they are wet with gas. There is no fire not even back fire. Its is like its just a dead turn-over, all clips are connected. Is it a possibly that if the starter was pooched and over drawing, wouold it rob power going to the coil and therefore the coil would produce a weak spark?
I totally agree that it has to be spark fuel or timing, its just that I have tried almost everything.
I changed to distributer and coil with known good parts, well from a running engine anyways.
could it be a short in the harness that prevents it from starting, unless the short kills the coil I would not think so....

Thanks for the help dude, much appreciated.

wde3477

hmm, closer, but no cigar - yet.

You may be onto something with the orange spark - it takes more voltage to jump a pressurized gap than when at atmospheric pressure. I suppose it is possible that the weak spark you're seeing may be unable to jump the gap at all under compression near TDC when it's seeing 8 - 10 times atmospheric pressure.

One hint that may be helpful - if you hold the accelerator to the floor when cranking - WideOpenThrottle, this is supposed to kill the injectors to clear a flooded condition.

As far as the orange spark, can't offer much other than to go through the system checking/verifying things such as coil and plug wire resistances, plug gaps, coil primary-side supply voltage, etc. against spec.

krashink

Yeah that what I been doing, very painstakingly. She getting the fuel and i think im gioing to change out the starter.

also wondering if you would know much about going to carburator, specifically wondering if the efi harness will work, from what i hear it will.

You seem to be a fountain of information.....

really appreciate your input.

Krashink

wde3477

no experience on a carb conversion. This forum had a recent discussion on that (I hopes I gets the link pasted right):
https://www.f150forum.com/showthread...light=efi+carb

To me, such a conversion is going backwards, giving up efficiency and diagnostic abilities. And such a conversion involves more than the carb itself. Yes, the conversion is possible, but why?

Unless you're flush with cash, I'd suggest that if the starter sounds normal, it probably is. At least have it tested before committing to a new one.

Keep in mind that every new part you add which doesn't solve your immediate problem has the potential to add a new "opportunity to excel" to the effort, thereby increasing the degree of difficulty.

wbstaz

By what you are describing, and the remedies you have taken so far, I would suggest, check make sure you have a really good earth to the engine, check make sure the rotor is turning, sometimes drive shaft can get worn!! The weak spark really is a clue, should be fat and blue!! Good luck. Billabong

vintage_car

if it is turning over but no start...have you shot any starting fluid into the intake to see if that gets it to fire? Your issue sounds similar to mine with the no start, but turning over. I had spark and I had fuel...it ended up being a bad tps (throttle position sensor). Just thought I would chime in with my fix...