I haven't looked at our nuetral safety switch but I know that on the cherokees that sometimes the damned things get gummed up and have to be cleaned and relubed with silicone grease.

 

The NSS wont affect the truck once its running, as it only interrupts the start cycle, not the run cycle. Sure, it does control the backup lights, but you could remove it once the trucks running and it wouldnt care. That is, until you had to shut it off and turn it back on again.

 

Actually the Bronco doen't have a NSS. They use a clutch interloc. The autos have a jumper in the plug from the factory that gets plugged into the clutch switch when you have the manual. The reverse light is a seperate circuit.

It does like you said, effect only the start cycle, not the run...

 

I think yo have a cold weather problem. When you enguage the tranny the fluid is pretty thick, The course of the engine having to warm up and cycle the fluid in park suddenly has to cycle the fuild for drive and it overloads it a bit.

 

Just as long as it isn't the computer, tc, tranny, or motor going out (or anything else major), I guess I'm fine. I'll just have to learn to be more patient. Thanks!

 

In reply to:

Actually the Bronco doen't have a NSS. They use a clutch interloc. The autos have a jumper in the plug from the factory that gets plugged into the clutch switch when you have the manual. The reverse light is a seperate circuit.

[/ QUOTE ]
that might be for the newer ones (92-96) but my '88 C6 has one - i had to replace it once already. It has a keyed hole in the center, and the shift linkage passes through it on its way into the trans. (Its attaches to the side of the trans.) Depending on which gear your in, it either completes the start circuits (N or P), turns on the backup lights (R) or cuts the start & reverse lights circuits (D, 1, 2)

But i agree, its probably due to the fluid being too thick from the cold weather. Let it idle for a minute or so and you should be fine.

 

Is there an additive he can use to help in cold weather? It seems that there would be. I'd like to know for my own info as well.

 

Well, I have found that if I have gasoline, it seems to run better than if I don't

Does that help?

(and NO that wasn't my problem, I have never ran out of gas)

 

What you are refering to Ford calls a Manual Lever Positioning Switch or MLPS.

 

oh

My manual called it a NSS, but i guess its wrong!

 

i don't think it became the MLPS until the E4OD days... I'm pretty sure the C6 in my buddy's 87 had a neutral safety switch to make sure the truck isn't started in gear.

 

UPDATE: I made a long drive yesterday (~60mi) and when I got to where I was going, I tried to back into a parking spot. I went from drive to reverse and then it died again. This time the motor was definately warmed up, and it wasn't that cold out (prolly mid 40's). I checked the tranny fluid and from what I can tell its low. I'll add more today, but is that another part of my problem, or is my tranny just getting finicky? OH, and I forgot to say that its only been dying when I shift into reverse, but its not everytime I shift into reverse.

 

when was the last good tune up? it almost sounds like its just a weak spark or something and at low speeds its just not getting enough something.. Either gas, spark or air. Does it have a new filter? Plugs and wires? fuel filter? Is there an idle adjustment on it? Could you turn the idle up a hair? Maybe a vaccum leak..

Just throwing some thoughts out.. Goodluck.

 

Alright, I guess its just time for some good maintainence. It needs the plugs regapped (too large), and it probably needs the air filter cleaned. How often am I supposed to replace the fuel filter? It was ~yr ago, so I don't think that its bad yet, but it has been 15-20k miles too.

I've also noticed that my truck idles faster in reverse, as in once its in reverse and I let off the brake and gas, it will crawl faster than it does in OD,D,2, or 1 and it will climb over stuff better too. This just seems a little odd to me, because isn't 1st supposed to be lower geared than reverse?

Anyway, I'll get caught up on my stuff and keep you advised if I continue to have any problems afterwards. Thanks!

 

Matteorr,
dont forget to check the throttle body plates for gum along with the air by-pass valve ports, two things that will definitely cause stalling at idle speeds, other items i can think of is vaccum leak, plugs as you stated (and if there bosch platinums-toss em

), and dont forget to check for trouble codes... looooong time ago , i had a stalling problem cuz the coolant temp sensor wasn`t working and altering the air/fuel ratio enough to cause it to die.

 

Yeah, but wouldn't a bad sensor (or sensor out of range) make the check engine light come on? I guess it never hurts to try it anyway though. And no, I believe they are autolight brand (if I remember right).

I have one of those throttle body spacers that I've been tempted to toss, so that might give me the initiative to do it. Of course, I might procrastinate until it gets warmer.

Today, I watched the tach when I shifted into reverse. It got down to just under 500rpm and then came back up to ~750-850 rpm. Does anyone elses get that low? I was just wondering if mine is getting as low as everyone elses and then can't hang on at that rpm, or if part of my problem is that it is getting that low.

 

Norm

an additive to thin out the tranny fluid, I cannot think of. I can suggest Castrol fully synthetic tranny fluid, at nearly triple the cost of regular ATF.

This allowed me to get in, start up and take off in -60 degree weather when the bronco was up in the Arctic. I don't use it anymore as I can't justify the cost for down here. I think Matteor's troubles may well be non-tranny related as others have been suggesting.

Matteor

If you do give a care about that tranny, plumb yourself a remote filter into the cooler lines and watch the shifts improve and the fluid get clean. I use this and change the external filter every month with the engine oil and filter and it keeps things clean between yearly internal filter changes.

Sixlitre

 

does the engine rough idle? ths would be a pretty easy indicator of a vacuum leak. my 1986 c6 had trouble when i first got it, and it turned out that a little vacuum actuated diaphram on the transmission had broken causing a vacuum leak, rough shifting and bad idle. it turned out that the vacuum was sucking tranny fluid back out of the tranny when it was in gear into the intake manifold (the source of the vacuum). not only did it cause my tranny fluid level to drop, also the heated fluid, as it passed through the engine and out the exhaust manifold, burned out my catalytic converters which is a bum deal if your state has smog laws like mine. i am not sure if your tranny has this diaphram, but it is worth checking, or someone else here telling you that you don't have it.

 

It seems to idle just fine. It will run almost as smooth as a kitten. I does dip a few rpm every few seconds, but I would hardly call that a rough idle.

But your advise isn't wasted. My dad has a 86 F-150 EFI302 and it idles horribly and has lost a lot of power. He has thought for a long time that it is a vacuum leak, but we've never tested to see. But now we have a good place to check when we do.

I was planning on changing my oil and rotating my tires this weekend, so I guess I'll start re-gapping spark plugs and clean the air filter too. Does anyone have any suggestions on an oil viscosity? I've been (and plan on) using Valvoline MaxLife 10w-40 in the winter, and I think 20w-50 in the summer (I might be off there though).

 

RE: Oil Viscosity

matteor
So, how cold does it get in OK?
From this page.
Yeah, it's from AutoBlown

,
but the info does look like the same chart I've seen in my owner's manual, and the factory shop manuals.

Interesting, upon further investigation, 5W-30 looks like the recommended weight for your rig.

With that said, I use Mobil 1 (10w-30) in the winter and Valvoline VR1 (20w-50) in the summer.
Remember though, that's a '69 351W in my rig.
How many miles are on your engine?

In response to Sixlitre's suggestion about the tranny fluid.
Since we moved here, I've always had Valvoline Durablend (Semi-Syn) tranny fluid in the C6.
No problems getting it to move, and we've had static, not with windchill, temperatures below -40°F this winter.

Now, getting the key to turn, gear selector to move, windows to work....in those temps is another story.

 

Re: RE: Oil Viscosity

Well, it gets down below 20*, but I can only remember the windchill getting below 0*. As for the summer, it does get above 100*, so it looks like I could use 10w-40 year round, but I'm okay with 20w-50 too.

Ive got 172K on the orig motor, tranny, etc. The only things that I've replaced in the 72,000miles I've had it, is the starter, fuel pump, plugs and wires, and tires (that I can remember). Oh and the countless gallons of gas too.

 

I wasnt referring to a throttle body spacer , but the round plate in your throttle body, guess you have the single TB since its MAF rather than like most of our SD dual throttle bodies, nevertheless, gum builds up on that plate and inside the passages of the idle speed control valve especially on sludge building 5.0ls and thus causes variations in the air /fuel ratio at and just off idle resulting in abnormal idle fluctuation & unexpected stalling.

Course, your EFIs system newer but i have NEVER seen the check engine light come on on my dash even having a code but things such as the gum buildup wont set anything off of course, just mentioning it cuz its the only item (not even a plugged fuel filter) thats ever caused my 5.0 to all of a sudden drop down to 500 rpms and then die, other than the coolant temp sensor which i mentioned. Sure there could be other causes though.

 

Yeah, I knew what you meant. I was just saying that while I'm inspecting for gunk, I could just take off the spacer too. My light has never come on either, I just thought that that might set it off.

Oh, and it does have 2 throttle bodies too. Theres one tube that comes out of the box with the air filter and after the MAF sensor, it splits into two separate tubes.

I just hope that its gonna be "warm" this weekend so I won't have to freeze off my fingers (and other stuff).

 

UPDATE: I got a little lazy this weekend. I didn't get my tires rotated or my oil changed, or the throttle body inspected. I did get half of my spark plugs regapped and tranny fluid filled back up.

I think that my spark plugs were/are part of the problem. They were gapped at .70 or more. I moved them all down to .50 or a touch more. After that, I started up my truck and pulled forward a little (I dropped the spark plug socket right after I got the last plug back in), and then backed up and the rpm dipped really low, but then came back up. It did have a little problem running at that rpm, but it didn't die this time.

I then pulled codes. The only code I got is one that I keep getting. Its a 538 (invalid cylinder balance test due to throttle movement during test), which I don't get because I never touch the throttle during the test. I'm wondering if it might be a build up in the throttle body, or maybe the TPS is going out (very slowly).

Anyway, that's what I've been upto. I'll get the rest of the plugs done tomorrow. It got dark too soon.

 

FURTHER UPDATE:

Today with weather in the upper 40's/lower 50's, it died on me again, not once, but twice. I started it up, let it run until it idled down, put it in reverse and started moving. Then it died. I popped it into neutral, started it back up, let it idle down, put it back into reverse, and watched the tach. It got down to around 400rpm, smoothed out a little bit, but it couldn't hold itself and died again. Then I started it, gave it some gas, held the brake, and put it in gear (at the same time). It ran fine then.

I haven't changed the oil, or cleaned the air filter or throttle body yet, but I'm wondering what's causing the problem (low idle), not the symptom (dying). It only does the low idle when going into reverse, so I'm thinking its some sort of tranny, tc, or computer problem. Can anyone give me some input on this? Thanks in advance.