No, I think the smoke test was done........to you.......but not the correct smoke test on the engine..........

Your right, that the mechanic should have spotter that vapor canister vacuum line on the spot.

The "short" your writing about, could first be a bad ground wire, battery to body ground, or battery to engine ground, that would also cause the problem your saying about the fluctuation in the volt meter on the dash.

The 30 amp fuse that blew, that's a whole another matter,
Which fuse was it? at which location, to which circuit??
That would narrow it down to where the short could be.

Just because new plugs/wires/cap were installed, on the ignition circuit, getting the correct voltage to that circuit is there, if the engine is running, plugs are firing, so on....

You keep writhing about 'engine idle problem'..........did you get all the vacuum hoses replaced?? Again, that will effect idle.

It's the problem that cause the fuse to blow, that needs to be addressed.

I worked on a Jeep Cherokee years ago, the guy couldn't get it started, and found the starter wire/ground wire loom, when opened up, the wires were corroded so bad, the insulation was rotted off the wires, could have been a real disaster. Replaced the wires, the connections were there, but the wires were shot inside the loom. He had several problems, and we got it going after that, but that's another story for another forum......

 

Well, the stalling issue is back and its also doing the same thing before the tuneup, While stopped in drive it wants to surge forward, then tries to stall, If I put it in neutral or park it does not stall or surge.
Thats why I was thinking its the transmission.

No, I have not had all the vacumm lines replaced
I did pull the engine cover this morning and looked around, tugged and squeezed on every hose I could get to for about an hour, I also disconnected some unused wireing, but all the other vacumm hoses feel sturdy, and connected tightly.

I think the fuse thing is not related to the rough idle.
The gauge dipping down does not do it all the time when the rough idle happens, only sometimes.
Dont know if this could cause the rough idle/stall issue but I I have way too much oil, i have an oil leak and keep putting more oil in, when I check the stick it shows way more oil than should be.
Also, Over the last couple years, my oil pressure gauge has been dropping down and down, and Several times the Van would not start, I would put a quart in and it starts up.

 

With the transmission in park/neutral, you're not putting any load on the engine, that's why it will idle, and not stall, in gear (any) your putting a load on the engine, causing the engine to "work harder" and stall.
Still not a transmission problem, it's an engine problem.

That's why the idle/park RPM's are set about 750, and when it's in gear, under load, the RPM's drop to around 550-600.

"........I also disconnected some unused wireing,........"

Why??? Were these wires OEM?? did they go to a sensor that was not connected? Were these wires something added for something else, like a brake controller, radio or something??
I don't think I would remove any OEM wires in the engine compartment that were not connected, even thought the connectors were not used.

"The gauge dipping down does not do it all the time when the rough idle happens, only sometimes."

Is this the oil pressure gauge?? I've had that problem before, and replacing the sending unit is the first step to 'check' that off the list, they do go bad, and for a $10 part, it's worth replacing to see if it's the gauge first, and not a problem with the oil pump it's self, or a plugged oil pick-up, which require dropping the oil pan.

"...........but I I have way too much oil, i have an oil leak and keep putting more oil in, when I check the stick it shows way more oil than should be........."

Just what kind of oil leak do you have??
Front / Rear seal?? Oil pan gasket, valve cover gasket??
Internal??
Way too much oil is a big problem.
I can not understand that you need to add a qt of oil to get it started??

When you check the oil, does it look, feel really thin? Does is smell like gas??
I ask, because that's a sign that the rings are shot, and gas is washing down the cylinder walls, into the oil pan, thinning the oil, losing the velocity of the oil, causing the oil pressure to drop also.
The only way to detect that is with a compression check, both dry for the valve seats, and then a wet compression check for the rings.

But, first, check your PVC valve, is it plugged?? Is it packed with oil? Is it working??
Too much oil in the pan (over pressurized) will suck oil up thru the PVC valve, dump it into the intake manifold, and mix with the air/fuel, thru the cylinders, and burn, kind of like a 2 cycle engine running.
You'll see a lot of carbon like build-up in the intake manifold if this is the case.

I think the first order is to replace the oil sending unit, to see if that solves the gauge problem,
Figure out where this oil leak is from.
Check/replace the PVC valve.
Pull the plugs to see if there is oil deposits/carbon on the plugs. Even though you just had new plugs installed, check then anyways.
Do a dry/wet compression check on the engine, to see if the valve seats are sealing, and if the rings are bad on the pistons.

 

The wireing I disconnected was not engine related, Probabley shouldnt have mentioned that.
It was the electrical gauge that dipped negative a few times, not a constant issue though, new battery and i had the alternator checked about 3 months ago, it was good.

Oil leak is from the rear main seal, have to remove the transmission to fix it. I had a dealer and another shop tell me the same thing.

I was told that there is a sensor that prevents the engine from starting if the oil pressure is too low.

The oil is not thin nor does it smell like gas and its clean.
I tapped on the pcv valve and i can hear the ball bouncing around but there is oil around the seal/grommet that its connected to. It looks like oil has blown through the seal.

Thanks.

 

OK, so wiring removed was not engine connected.

You didn't specified which gauge was "dipping", now that clear.
Alternator gauge will dip with a voltage draw, like with the turn singles on, but if your having almost stalling problems, the engine is loosing RPM's, and the belt is not turning the alternator fast enough to produce voltage, thus the gauge dropping to the negative side.
All engine electrical control, lights, radio, what ever, pulls voltage from the battery, the alternator only "re-charges" the battery, it does not run anything electrical in the vehicle.

Yes, the tranny needs to be dropped, and flex plate removed to replace the rear main seal, and this is very common problem with the 351W.
*along with many other vehicles and engines*

If the oil leak is really that bad, then it's worth repairing.
Other wise, on a long run/trip, your going to run out of oil, and have other problems. Beside a messy driveway.

"I was told that there is a sensor that prevents the engine from starting if the oil pressure is too low."

You have mentioned this several times, and I've never heard of this.
On lawn mower engines, and generators, yes, oil level sensors, not on this era engine.

Oil will blow thru the PVC valve/seal if the oil is pressurized too much, like to much oil, or bad rings, causing "blow-by"
To much oil in the crankcase could also contribute to the rear main seal leaking really bad, too much pressure.

 

Would an ICM or PIP sensor going out (or getting really hot) allow the engine to start when cool but no when hot and cause the stalling issue I had mentioned?

Or when those go bad, the engine doesnt start at all?

Today I stopped after driving for a while and it would not start, after waiting about 20 minutes it started right up.
The ICM is only around $60 and looks really easy to replace, the PIP on the other hand looks like it would be a pain.

Thanks,

 

I had a PIP burn out on a road trip years ago, when they go, there gone, and you can tell with the black soot inside the distributor cap. Mine was running rough, and mis-firing every once in a while, then it quite, and was baked.

I found this LINK, even thought it's for a late 80's F series, it's close to what we have.

There are several test you can do to check the PIP and ICM.

Replacing the PIP, it's better to just get a brand new distributor and replace the whole works.
I had an old one that the bearing was shot in the dizzy, replaced with new.

I would guest your problem could be a fuel pump starting to burn out, when hot, shuts down, cools off and you can re-start. OR a relay over heating, like the fuel pump relay.

As JWA always posts, keep your fuel gauge above a 1/4 tank, that Does keep the pump cool.

Could this be the other problems your having, yes, a bad fuel pump would cause the stumbling/stalling your having, but not the high idle.

Best if you can check the fuel presser at the rail, KOEO and KOER, would solve alot of guest work, and alot of unneeded parts.

 

Its tough for me to do much work on the van because it is my only transportation to work.

There is no high idle, Just a miss at idle and the hard starting when hot issue.

I am almost inclined to go ahead and replace the Ignition control module and/or the ignition coil just to rule them out as a cause, I can do them pretty easily but checking the fuel pressure would be difficult, dont have the right tools and if something went wrong I would be stuck.

Thanks.

 

Also, I have always heard the fuel pump, as soon as I turn the key, I can hear it.
I didnt pay attention to it when it did not start today, next time it wont start I will remember to listen for it.

Thanks.

 

I had a very loud fuel pump when key'ed on.
And, if I could hear it, it was loud, cause I'm part deaf.

I changed it out before I had problems, and the new one I can feel running, and hear it humming, and the pressure is up to spec's.

Guest the next time you have a no-start, hear if the pump is running when key'ed on for 2-3 seconds.

If you have a no-start, pull the relay out and put a jumper in the slot to see if the relay is bad when it's hot.

You can "borrow" a fuel pump tester from the auto parts store, just make sure you get the small adapter for our trucks.
It only takes 10 minutes to check the pressure to see what you have.

Sorry if I was confused with the high idle, from another topic.........

 

Between the Igition control module, the ignition coil and the PIP sensor and given that I have a bad miss , and the engine stalls sometimes when I am at a stop idling in drive, (if I put it part or neutral while stopped it wont stall) and sometimes it wont restart unless I let it cool down for 10 minutes or so, Which of the three should I replace first?
I still do want to check the fuel pump and pressure but I figure I could do the easy stuff first, LOL.
Thanks.

 

I'll post up this link, you can find which sensor you want to run a check on, most "test" are basic and simple with a few special tools, like a volt meter.

Part 1 -Ford 4.9L, 5.0L, 5.8L Index of Articles

Click on which sensor you want to run a test on, But, check the right side bar to make sure that sensor/test has your year/model/engine listed as applicable.

Also, did you run a OBD on this?? Check for any codes??
Even thought the CEL is not on, you will have some codes stored in the ECM for running problems, that is, if you have not disconnected the battery for any length of time.

EGR problems don't always set the CEL on, and with the "stalling" problem you have, could be related, dirty, stuck EGR valve.

I understand this is your only set of wheels, but with that thought, if you don't resolve the problem, you'll have no set of running wheels.
Been there, that's why I have a 2nd vehicle, just to save on running around in a work truck all the time, and for one or the other in for repairs, and for running to the part store for more stuff I forgot to get. I know not everyone can do this, but it's just a thought.

 

Yea, I have a small OBD1 computer and I didnt get any codes that were engine related.

Thanks for the link, Ill check it out.

 

Well, I called up the mechanic that I had takent it to and told him I found two rotten/broken vacumm lines.
So I took it in and he replaced both vacumm lines I had taped up and he did a smoke test (this time LOL) and found a leak at the EGR valve line and fixed that (no charge), But..... The engine does the same thing, a slight surge forward when stopped in drive. It only seems to do it when warmed up.

 

The fuel pump could be bad, thinking mine is due to a miss, and lean codes, I have almost 150,000 miles on it, original pump too, if yours is similar, you may want to go ahead and have it swapped out.