86ish D150 225 goes 1/2 a block then dies, won`t restart until cold

Hi guys,

this truck is possessed it is a mostly 82-86 D150 225 SL6 with some parts that are not even close to what goes 1/2 a block then dies, won`t restart until cold

i bought it last year and worked on it last summer -- after several small things, set idle, etc., was running fine last summer, missing a bit

it idles fine and i leave it to warm up until it reaches curb idle

sometimes it stalls on idle but not usually and can usually be restarted

but, once it goes on a test run it dies after a few hundred feet, then will not restart until cold no smell of flooding when it dies so not a fuel too rich problem the problem has been getting progressively worse and worse -- to start with, it would drive for about 20 minutes before dying, then same thing

-- would not start until cool

I AM going to trace the wiring from the coil capacitor to distributor tomorrow by tearing up the tape, but I have had some help from my new boyfriend -- between us both this is all the stuff we have changed so far -- if it says used it was working on the other 86 D150 before I stole the part:

-- checked all vacuum hoses, and checked for leaks

-- checked rad thermostat

-- checked grounds

-- complete tuneup with new rebuilt distributor, cap, rotor, wires, plugs, new coil (plugs were very carbonated)

-- blew out gas lines with compressor -- seemed to work for a while but not second or third time

-- replaced fuel pump, fuel filter

-- made sure tank always 1/2 full in case of rust in tank

-- replaced carb (holley 6145 1bbl), adjusted carb (curb and fast idle), put 1/2 bottle of carb cleaner directly into carb, and another 1 1/2 bottles into gas tank

-- replaced egr valve, breather cap, pcv valve

-- replaced choke assembly(used)

-- replaced air filter

-- complete air breather assembly (used)

-- replaced computer (used)

-- replaced voltage regulator

-- checked compression: cylinder 1: 145 cylinder 2: 147 cylinder 3: 145 cylinder 4: 145 cylinder 5: 55 cylinder 6: 147

-- adjusted timing to 18 degrees -- +/- 2 degrees

set curb idle to 825-875 (about 75 high due to rough idle -- weak no.5) set fast idle to 1700

-- one gas line was changed last fall when it passed a quebec safety so, since the brakes, power steering, new tires, excellent body, lights etc., all done, it is almost like new -- will swap motor with my other D150, but need to get it running -- and stay running first

-- it is supposed to be my daily driver and i am still driving my brother`s spare car

any ideas will be greatly appreciated

rach

Reply to
Rachel Easson
Loading thread data ...

It won't restart because it doesn't have gas or spark? Which is it?

Robert

Reply to
BigIronRam

i don`t know -- but i just thought -- i`ll take a wire off the coil tomorrow night -- had a few beers now and do't feel like doing it now unless i can't sleep later -- and see if it sparks

i think it`s fuel related because when it stalls there is no gas smell at all -- but maybe this might help -- any more diagnositc ideas?

I have located a plastic gas tank with sending unit -- if i pay for a garage and hoist i`ll have the last two gas lines and tank replaced at the same time (old steel tank probably full of rust which is why i have been keeping the gas tank topped up)

thanks robert

rach

Reply to
Rachel Easson

How have you got the idle mixture screw adjusted? It should start and run with it set 1 1/2 full turns from lightly bottomed and the curb idle screw at 1 full turn open. Then adjust for best idle at 700 to 750 warm. Fast idle should not have to be over 1000 -1200 rpm. Reset the timing between 10 and

12 degrees Before Top Dead Center. Also check the heat riser valve on the exhaust manifold. If it's stuck open you could be stalling due to carburetor icing.
Reply to
Budd Cochran

Running a few hundred feet after a cold start and dying sounds like the float bowl is running empty. I have had a float stick on a Holley 7855 do that a time or two. But, you've changed carbs....

Robert

Reply to
BigIronRam

Yup..sure do.

Cylinder 5..you SURE about that reading?

If its that low, and you have a cat on the thing..cut it off with a sawzall and drive it home.

Reply to
CAVHBC

i can`t spell when inebriated either ;-)

positive -- checked it three times now -- the other readings are consistent too

no cat converter (or smoked cats for that matter heehee) -- i wish

rach

Reply to
Rachel Easson

That could be as simple as a bad connection on the coil, bad splice in the ignition lines, failing ballast or a failing ignition module.

That sounds like a fuel problem but could still be the ignition.

Even if the ignition cuts out, you still will not get a flooding smell. Do you have a timing light? If so connect it when the engine dies and and see if it fires off while cranking. If not, then you most likely have an ignition problem. Actually, a dwell meter would work better for this but they are getting hard to find with todays electronic ignitions that don't need them.

That is NOT GOOD. You may have a real problem with #5. Do you have a compressor? If so, they make a fitting for it to connect your compressor to the cylinder and is used to hold your valves in place with air pressure to allow you to replace the seals and / or springs without removing the head. It can also be used to check for leaks and where they are. I would look into getting one and connecting it to that # 5 cylinder, make sure that #5 it is on its compression stroke, hit it with around 100 lbs of pressure and see what happens. If you hear air hissing out of the carb or exhaust, you have a valve problem and should probably get by with that for a while. If it sounds like it is coming out of the breather it could be bad rings and I would do a wet compression check on that cylinder to confirm that. If the compression does not improve with a wet test, you probably have a damaged piston or severely damaged walls and I would be concerned about its reliability. If you hear nothing at all, then you may have a bent connecting rod and I would not trust or use that motor without further inspection.

That sounds a bit over advanced.

Fast Idle is to fast but should have little to do with your current problems.

With that #5 cylinder, I would not invest much money in THIS motor.

Good luck.

Reply to
TBone

i see what you mean about getting a dwell meter -- Princess Auto -- my favorite store has 78 pages of hand tools and not one dwell meter. i will check napa though since i am about to leave to go there

i do have a timing light so i'll try this test -- thank you for the tip

holy shit is that ever cool! i just returned my campbell hauser 8gal and am waiting for a larger stationary one to go on special. i have access to two others in the meantime -- i need good tools because i am not that strong -- i'll check on this while at napa

i love you guys!

that would be what budd mentioned with squirting the oil in #5 yes?

If the

thank you

the manual said 16 -- and it sounds good -- but i'll check my chilton manual today -- had that on my list to do -- budd told me 10-12 degrees

yes a bit fast but it runs smoother and sounds happier

exactly -- depending on how bad it is, will decide when this season to deal with it i am starting to think that ultimately changing its 225 with its twin's is not the way to go -- instead take all the new parts easy to access off Possessed and switch with its twin's old stuff, keep the twin with the body work to do

this april i have to

- fix starter and flywheel in 87 4x4 dakota, do a bunch of body work and put it up for sale -- motor is on its way out -- no burning oil but no power under load -- -- it's ugly, don't need it

get a daily driver

i need a 4x4 for winter so i could get my little 88 4x4 dakota with cracked block ready first (do floor and interior incl. seats and belts, rad, then have motor installed, and start driving it so i can give back my brother's car before end of april)

or

deal with "Possessed" -- see if its old 6145 carb was good (now squeaky clean) -- borrow choke back, and see how the twin runs, if ok, consider installing a manual choke i have -- sell off Possessed, work on twin -- if old carb was good, install manual choke, otherwise consider electronic fuel injection conversion, do body work later

either way, it is a lot of work

thanks tbone, i'm going to need it!

rach

Reply to
Rachel Easson

Even pulling the coil wire out of the distributor and holding it a 1/4" from the block will tell you if you have spark. Dwell meters are hard to find since the advent of electronic ignitions . . but I have a very old one. BG

By way of explanation, if the valve is burnt or bent, this will not help you. You will still need to pull the head.

To do the test Tom mentions, you need an air hose run all the way to the truck, if it's not in your shop ... and I think you said it was out in the field? I suggest the compression guage . . .it's a bit more portable and will do the preliminary testing.

Yes, it is. I just gave a description instead of the name since you are new to auto mechanics. Trying to not cause confusion for you.

10-12 will get you started a bit easier and load the battery down a little less while cranking.

Don't throw the block away until you've pulled the head ( watch out!!! It's heavy!!!) and looked at the bores. If there's no serious scoring ( a fingernail catches on them) then it's not likely to need much overbore if any. My first /6 had 133,000 miles on it and the bores had 0.002" wear. The rod throws and mains were worn only 0.0005". Knocked out the ridge, honed the bores and put in all standard sized parts.

Btw, a quick way to boost compression is to mill the head up to 1/10 of an inch. It raises the static compression ratio one full point.

Budd

*** Free account sponsored by SecureIX.com *** *** Encrypt your Internet usage with a free VPN account from
formatting link
***
Reply to
Budd Cochran

Distributor pick up will sometimes act that way.

Is 12 volts still available at the coil when the engine stalls? I have seen corroded terminals in the bulkhead connector or the ignition switch wiring connector produce similar symptoms. I may have missed some of this thread. Just offering some ideas I didn't see.

The slant 6 is a good motor. Like the older ones with solid lifters and a 2-barrel carb better. Had to run one with three weak cylinders for a couple years until funds were available to get another.

Reply to
shafferf_at

ive always used the hose from my compression tester for that. you just have to remove the shrader valve. my compression tester has a fitting that my air hose will plug right onto, works great.

Reply to
Christopher Thompson

To remove a valve, yes, the head has to come off. If you only want to change the valve springs or seals without removing the head and you don't have an air compressor there is another way. Remove the push rods or rockers and spark plug, then roll the crankshaft until the piston is all the way down. Feed a foot or two of clothes line into the spark plug hole. Leave some of the rope hanging out of the hole so you can get it back out when you are finished. Turn the crankshaft (by hand) until the piston pushes the rope up against the valves. The rope will hold the valves closed allowing you to remove the springs and seals.

Reply to
Nosey

T-bone failed to mention what to do if his test showed a bad valve. Besides, bad valve seals won't drop the cylinder pressure to 55 psi. Another possibility, but pretty rare on /6's is a blown head gasket. Usually they blow between two cylinders and that drops the pressures for both of them, which is why I don't suspect it with her engine.

Reply to
Budd Cochran

First, using compressed air to hold the valves in place is a risky affair. Use a length of cheap clothesline inserted in the plug hole and run the piston up against it to hold the valves closed. Safer and easier than hoping the air prssure doesn't bleed past the rings too fast.....

WHICH IT WILL DO given the compression reading.

But I have to ask, how the hell are new stem seals going to help compression? Why are you even suggesting somehting like that regarding a low cylinder pressure reading?

Sure it can, but it won't tell you if its a normal rate unless you have a leak down tester.

Um, NO. If its an exhaust valve, what you've suggested is a good way to burn the valve and the seat, causing more damage. If its an intake valve, what you've suggested can result in backfire through the intake, which has no good effects at all.

A bent connecting rod in a slant six is >almost< impossible, and certainly would be accompanied with other noise if it did occur.

Not on a slant six.

Fully agree, 1700 is way too high for idle speed.

Reply to
Max Dodge

Or that you don't have it exactly at TDC, in which case the air blows the piston back down... usually right after you remove the keeper :)

Reply to
Tom Lawrence

Are you really this desperate Max. Who the hell is telling her to replace either seals or springs. I was explainig the purpose of the tool so in case she wants to get one, she can tell the salesman what it is used for since I don't remember its name.

That is the whole idea, to find out where the pressure is going.

I am doing no such thing, moron. It is a TEST TO SEE WHERE THE AIR IS GOING IF ANYWHERE AT ALL. Perhaps you should read the whole thing before making a complete ass out of yourself.

LOL, it will show you where you are leaking from. I guess your engine diagnostic ability runs right up there with your electrical knowledge.

Hahahahaha, you really are a retard. How is pushing 100lbs of air into a non-running engine going to cause either one of these conditions? You do know that when it is on its compression stroke both valves will be closed, right????

WRONG!!!! It can happen, I have seen it and it caused NO NOISE AT ALL and I never said it was the most likely cause of the problem, only that it could and is far more likely than your bad battery in the other thread.

Reply to
TBone

LOL, if the rocker arms were removed, who cares. The pressure will still not drop enough to let the valves fall but then again, nobody is suggesting replacing springs or seals anyway. The tool is only being used to determine what, if anything, is leaking.

Reply to
TBone

That would require someone else cranking the engine and the risk of being shocked. Most timing lights have long enough wires to bring it into the cab with you and hold the trigger while cranking and if not, a simple rubber band will hold the trigger and you can lay it on the air cleaner where you can see the lens while cranking and no risk of shock.

But the test will confirm it and that is the whole purpose of doing this, to see where the air is leaking from.

I guess reading isn't your thing. If you look above, you will see some compression numbers. How do you think she got them, here is a hint, a COMPRESSION GUAGE. The test I suggested using the air chuck will help to determine where the air is going.

Reply to
TBone

I didn't mention anything because there is nothing to do. If it has a bad valve, that's it since she intends to replace the engine anyway and if it is a bad exhaust, just let it run that way until she gets around to replacing it. Where in the hell are you idiots coming up with this bad valve seal crap? Replacing valve seals, retainers, and springs is what the tool was intended for, not what I am having her use it for. Perhaps a first grade reading class is in order.

Reply to
TBone

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.