Strange fuel starving after changing fuel filter
 

So I finally got around to swapping out the fuel shut off solenoid instead of having the emergency kill cable and I love it. while I was in there I changed the fuel filter and now I'm having a strange starting problem.

unfortunately it doesn't seem to be really consistent -but what happens is I will drive a short distance i-n other words,start the truck do something for under 5 minutes - and then shut the truck off; and then when I go to start it again it simply cranks like there's a fuel problem. Then I wait for 2 to 5 minutes and then it starts up without a problem.

any guesses on what's going on with that?

It could be the the wire on the fss, usually a spade and they get loose. If you have a multi-meter or even a test light when it is not starting leave the key on and see if there is power to the fss.

I came back to post about this issue and realize that I had posted before thank you for this answer but what would this have to do with it starting after waiting a few minutes?

I did test it for power and the FSS does have power when the ignition is on and doesn't when it's turned off there is that other solenoid that's easier to get at below it and that too gets power and shuts off when you turn the key off so this doesn't seem to be an electrical issue.

I just had another real problem where I drove about an hour shut off the engine for 5 minutes and then it wouldn't start for another hour. it felt to me like once it finally cooled off then it started up

trying to diagnose things I opened the injectors and when turning the crank fuel was squirting out of them so it's not like the fuel shut off solenoid is stopping fuel, right?

does anyone have an opinion about maybe I put the fuel shut off solenoid in wrong not tight enough and so that when it heats up -it lets a leak through?

it does almost sound like there's air in the line but what does that have to do with my changing the FSS?

What I was saying is when you try to start it and it wont start leave the key on and check to see if you have power at the fss, also is this a first gen or a second gen I see a 94 in your sig.

If it is a second gen when it won't start leave the key on and reach down where the fss hooks to the pump and manually lift it up (which is on) if it clicks into place you either have a bad fss ot the lift side wire is not working. I have had that happen before.

I've got a 1st gen - 1991. Can't get my hand by the fss, especially when hot

There is not much that is very hot on the fuel side of the motor, near the FSS.

”91.0 and a ‘91.5 are very different motors and injection pumps. Telling us you have a ‘91 is barely more helpful than just telling us you have a 1st gen.

Oliver, I see in his sig that it is an intercooled truck so it's a 91.5 which like you have said before has those "one year only problems". Like you say there shouldn't be anything hot enough to keep you from shecking it with a multi-meter when it doesn't start, just leave the key on and see if it has power to eliminate that as a problem.

Okay I guess I'll drive around with my multimeter and see if the problem reoccurs and check it at that time.
doesn't it seem much more likely that there's some sort of leak or fuel problem rather than electrical given that after waiting a while it starts back up?

The issue I'm having trying to figure out if it is a fuel related problem is that if it starts up fine and you drive it with no issues and shut it off, then come out after 5 min and it won't start, and I assume only crank with no white/gray/black smoke coming out of the exhaust? If you were getting air in the system it would either lock up the injectors and you would need to crack them open and prime to get it running, or could be rough to start, white smoke and eventually get going then clear up after 30 sec. Air issues in the fuel generally don't clear up after a few minutes sitting and waiting.

If it's crank with no firing then it most likely means not getting fuel, and if you installed a new FSS then I would suspect that might be your problem. The FSS is a small electro magnet and can have electrical/heat related issues. My youngest drives a 88 Aries K-car and years ago had a run well for 5-10 min then die...no start. no spark, wait 30 min and would fire no problem. Many hours, many parts, much research later I finally found the problem....I had installed a new magnetic pick up in the distributor and what was happening was there was a fault in the new part and when it heated up that fault would widen and the connection would be lost...so no spark, no start. Wondering if your FSS is having the same issue....gets heated up and then won't energize properly and pull up the plunger, wait a bit for it to cool off and then it does start working/

thrashingcows, much better explanation than mine for sure, on my truck when this was happening i had an intermittent electrical short in the wire and that was why I asked him to check power when it wasn't starting. Another thing he could try is use a wire with alligator clips and go directly from the + on the battery to the fss and see if it starts then.

THIS sounds like the real deal. to answer your question: no smoke (not even SMELL from the exhaust) - and I did crack injectors and it didn't help. just crank and crank.

WHEN I have this issue again, I can try running a positive line right to it. But, what do you think I should do to completely fix it? different FSS? when you say 'fault'... do you mean 'bad part'/needs replacement, or some sort of ground fault that I could fix if I found it?

I would think on those as they are not "serviceable" you would have to replace it to fix that problem if that turns out to be the case, but do make sure it is getting at least 12v at the fss when it does this.

Nonrev's wire is an essential tool, IMO. One has lived in my glovebox for at lease a couple decades. It will get you started, but is limited diagnostically. The voltmeter will determine the actual voltage to the fss which might help pinpoint a problem like, perhaps voltage doesn't drop to zero, perhaps it just drops beneath the threshhold necessary to actuate the fss. Just shooting from the hip, as usual. I'd use a voltmeter and determine the fss has 12 volts when the engine won't start. If so, I'd swap out the fss.

Just because a part is new doesn't guarantee that it does not have a defect, so I'd replace it with another new one, or if you can find a good used one that has been in service for a few years that would be even better IMO. ;)

maybe before you hook up the 12V jump wire have a container of cold water to pour on the FSS to cool it down quickly, then try to start it, if it starts right away then it's a very good chance the FSS is the problem and not in the 12V power wire(s) to the FSS.