I have a 87' D150 with a 106K /6 in it. Lean burn, 6145 1bbl holley, all emissions intact except no belt on air pump. This will be the second winter I have run it, and as the temperatures start to dip in preparation for the Alaskan winter my truck warms up increasingly more poorly.

First of all, the truck always fires with just a few starter cranks, but if it is anywhere below or around 35F the truck will stall out after just a few seconds. If I really put my foot in it, it will sometimes fight through, but it's not really worth pouring the gas in to it. I then start it right back up and it will stay running fine (relatively speaking.. I'll share more later). What is this an indicator of? Is this a fuel delivery problem (fuel pump, clogged fuel filter/lines) or more likely carburetor related. My starter is feeling abused...

So the truck is up and running, but if the weather is cold it will not stay idling without some gas pedal from myself (forgot auto-start, this is manual start at its coldest). Depending on how the truck is feeling with no pedal input from me, the rig will either idle unbelievably anemic (like barely running) and die shortly thereafter, or just die immediately. The truck will idle smoothly only when the temperature gauge reaches normal running temp (about the second notch on the gauge), until then idle quality is total $#!+ even when the temp gauge first starts to read. When it does finally settle in it idles perfectly (although a little fast) with no misses or sputters. I originally thought it was a choke problem, but after some investigation the choke mechanisms seem to be working properly... what could cause this? bad temperature sensor? vacuum leak? problem with lean burn system? Tuning???

Also, when warm the idle seems pretty high in park as well, drops into gear pretty stiff for my liking.

My other plea for diagnostic concerns when I shut the engine off. If it has been running warm for a normal amount of time when you turn it off the engine often diesels over. More often than the dieseling however is a loud snorting sound (usually in conjunction). I originally thought it to be some sort of radiator chug but after watching shut off with the air cleaner off, when the chugging noise happens gas/air/??? blows up out of the top of the carb. Also my air filters seem to get unnecessarily dirty, which could be from this blowback. What could possibly cause this backlash through my intake/carb?

I appreciate any input from you folks... hopefully someone can give me a place to start.

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1987 Dodge D150 Shortbox /6 904 auto
1982 Dodge D150 Longbox /6 833OD 4spd

Since the air pump is not working what have you done about the Cat? If its not removed it will clog and really play havoc...Ask me I know as I have had this on my 82 and 87.
Frank

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

I know You have been through the choke already, but I think that is where your problem lies. The choke should not only be basically closed when cold, but the fast idle Cam which is hooked via linkage to the choke should be running the truck at start at about 1500 rpm. The fact that it barely runs most of the time cold is indicative of a non functioning choke, and associated hardware.

I haven't ever run a choke on any of my /6, which generally only means that it takes a bit longer to start which is fine for me because the oil light is out before it fires. Then I simply keep it running.

I would first re-verify that your high idle Cam on the Carb is pushing the throttle plates open, and that the choke is pulling off correctly. After that, I would verify That your emissions equipment is in operational shape, assuming you utilize it.

~RDE~

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1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

I've had some similar problems, and the first time it turned out that although the choke was properly closed cold and open hot, the bimetalic spring was fatigued and it would open way too fast. In cold Michigan weather, it would start fine, then tend to be stall after a minute or so (choke would be wide open) and keep stalling until the engine really warmed up. Pouring water on the choke would temporarially cool it off and let me get going. I then put in a manual choke.

The second time, the 3-port thermal vacuum switch on the radiator opened before the car was really warmed up, and that turned the EGR on way too early. Again, very cold and warmed up was fine - just in-between gave problems.

I agree with THOR. Have someone else start it so you can watch the choke at work. If no one else can help, then try and start it and let it die on you like normal. Then look under the hood and see if you are on the fast idle cam or not. I suspect either you aren't on it, or you aren't on it high enough to where it'll idle fast enough to not die out on you.

The deiseling sounds like it's because you are idling too fast at curb idle. There shouldn't be a stiff drop into gear from Park and your truck probably sounds like Mickey Mouse turning off his car in an old 1930's cartoon huh? Where it kinda wheezes and then blows air out of the carb.

You need two tools to fix this stuff. An rpm gauge or engine analyzer as well as a timing light. I don't know the exact specs for an 87 so I'm just going to give you some general specifications. I'm also assuming Alaska probably doesn't have emissions laws since many people don't live there. Set your timing between 5-10* BTDC. Let your motor warm all the way up and set it to 750rpm in park. Put it in gear and it should drop to 550-600rpms. If it runs smooth there, then drive it like that and see if it works out. Now I live in CA where it's not nearly as cold so you may have to bump up your idle in park to 800rpm to keep it running smoothly. Above that, the idle is too fast to my liking and makes it prone to run on or deiseling.

You'll also want to set your fast idle speed for when your choke comes on. I haven't done this in years but I believe you set the fast idle screw on the top step of the fast idle cam. Then you set your rpm to 1200rpms. As your engine warms up, the fast idle cam will move down each step until your engine is fully warmed and off the fast idle cam. Do this when it's cold and hasnt ran all night. Like I said I haven't done that in a couple years so either read your book to see the exact specs for that or get the instructions from someone here.

I agree with the above diagnoses that your problem is in your fast idle and choke adjustment. I was born and raised in Anchorage, so I know what Alaskan winters are like. I remember being the one sent out at 5 in the morning to go start the car to let it idle for 1/2 an hour just to get some heat coming out of the vents. However, I also believe that a properly set up carb will work just fine in even sub zero temperatures.

It sounds to me like your fast idle is too high but your choke doesn't close enough. As previously mentioned, your fast idle should be somewhere between 1200 and 1500 RPM.

Proper choke operation is as follows:

(1) when the motor is cold, as in first start of the day cold, opening and shutting the throttle should cause the choke butterfly close fully.

(2) Opening and shutting the throttle should also cause the fast idle cam to drop under the fast idle screw so the fast idle screw is resting on the highest or second highest step of the cam.

(3) As soon as the motor starts, the choke pulloff diaphragm on the carb should pull the choke open roughly 1/4 inch (this is a ballpark distance, the true distance varies on either side of 1/4 inch depending on model of carburetor, emissions package, vehicle equipment etc...)

(4) engine speed at first start in cold idle should be somewhere between 1300 and 1500 RPM, but 1500 is rather high.

(5) as the engine warms up, the choke should slowly open and, at the same tim, the fast idle linkage should slowly move, moving the position of the fast idle cam until the cam is completely out from under the fast idle screw.

I also agree with 66aCUDA's suggestion that you replace or remove the catalytic converter. It is highly likely that the converter is clogged and causing problems. Disconnecting the air pump will hasten the demise of the catalytic converter since oxygen is no longer being injected into the exhaust line (or directly into the catalytic) to assist in post-engine exhaust combustion.

I would also highly suspect both the lean burn computer and the computer controlled carb. The lean-burn system is notoriously faulty and leads to all sorts of driveability problems. I highly recommend that you swap the carb for a Holley 1920 and the ignition system for HEI. However, your truck is a 1987 model. I have heard rumors that some of the 1987 year trucks had an electronically controlled lockup torque converter controlled by the lean-burn computer. Investigate this before you modify anything.

If you don't have access to a helper, you can check the choke operation by putting the ignition switch in run and starting the motor while you are under the hood using a remote start switch or a screwdriver to jump the terminals on the starter motor.

You should review the carburetor adjustment methods described in THIS thread. You also might need to replace the O2 sensor if you are keeping the lean-burn system.

I don't remember if AK still does visual emissions equipment inspections or if they just have the sniffer test. I know that I can get vehicle to pass the sniff test here in Washington with most emissions devices disconnected or removed so long as the engine is in a good state of tune. Long term, I recommend you dump the lean burn systems, remove the catalytic converter and all other emissions equipment (except the charcoal canister and PCV valve).

You should also make sure that your heated air intake system is intake and working properly, as well as the cold air intake system.

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Casually looking for a Clifford hyperpak intake for cheap.

Now that it's getting into the 40s on some mornings in my area, I'm noticing these same issues with the cold start-up on my 76 Valiant.

I'll be checking all of these things over the next few days.

Did the 76s come with catalytic converters? The last time I was under the car, I thought I remembered seeing that it did have one. (the exhaust system is original on my car)

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1954 Ford, Tudor Mainline
1976 Plymouth Valiant, 4 door


www.automotive-ninja.com

I think 1976 was across the board passenger car catalytic converters, except the lean burn 400 4V in Cordoba 49 state spec vehicle. California spec 1976 lean burn I don’t know about. By 77 the 400 4V had a cat.


Reed:
I also agree with 66aCUDA's suggestion that you replace or remove the catalytic converter.


Reed, one has to be careful about removing catalytic converters, check federal law, I believe it’s good for a $10,000 fine, and or jail time.


Lazy choke repellent:
To keep one’s choke operating properly, at every cold start (first of the day only), depress the accelerator to floor to set the choke, and start the engine. Even in warm climates this will keep the mechanism moving freely until cool weather returns.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

For those who don't know, U.S.C. stands for "United States Code." The United States Code is the Federal statutory law.

42 U.S.C. § 7522 provides, in pertinent part:

(a) Enumerated prohibitions

The following acts and the causing thereof are prohibited--

***

(3)(A) ...for any person knowingly to remove or render inoperative any such device or element of design after such sale and delivery to the ultimate purchaser; or

(B) for any person to manufacture or sell, or offer to sell, or install, any part or component intended for use with, or as part of, any motor vehicle or motor vehicle engine, where a principal effect of the part or component is to bypass, defeat, or render inoperative any device or element of design installed on or in a motor vehicle or motor vehicle engine in compliance with regulations under this subchapter, and where the person knows or should know that such part or component is being offered for sale or installed for such use or put to such use;

***

No action with respect to any device or element of design referred to in paragraph (3) shall be treated as a prohibited act under that paragraph if (i) the action is for the purpose of repair or replacement of the device or element, or is a necessary and temporary procedure to repair or replace any other item and the device or element is replaced upon completion of the procedure, and (ii) such action thereafter results in the proper functioning of the device or element referred to in paragraph (3). No action with respect to any device or element of design referred to in paragraph (3) shall be treated as a prohibited act under that paragraph if the action is for the purpose of a conversion of a motor vehicle for use of a clean alternative fuel (as defined in this subchapter) and if such vehicle complies with the applicable standard under section 7521 of this title when operating on such fuel, and if in the case of a clean alternative fuel vehicle (as defined by rule by the Administrator), the device or element is replaced upon completion of the conversion procedure and such action results in proper functioning of the device or element when the motor vehicle operates on conventional fuel.


Section 7549 deals with high altitude conversions.

42 U.S.C. Ch. 85, Subch. II (in which this section is contained) is titled, "Emission Standards for Moving Sources"

However, 42. U.S.C. section 7521 provides, in pertinent part,

(a) Authority of Administrator to prescribe by regulation

Except as otherwise provided in subsection (b) of this section--

(1) The Administrator shall by regulation prescribe (and from time to time revise) in accordance with the provisions of this section, standards applicable to the emission of any air pollutant from any class or classes of new motor vehicles or new motor vehicle engines, which in his judgment cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare. Such standards shall be applicable to such vehicles and engines for their useful life (as determined under subsection (d) of this section, relating to useful life of vehicles for purposes of certification), whether such vehicles and engines are designed as complete systems or incorporate devices to prevent or control such pollution.

(2) Any regulation prescribed under paragraph (1) of this subsection (and any revision thereof) shall take effect after such period as the Administrator finds necessary to permit the development and application of the requisite technology, giving appropriate consideration to the cost of compliance within such period.

***

(d) Useful life of vehicles

The Administrator shall prescribe regulations under which the useful life of vehicles and engines shall be determined for purposes of subsection (a)(1) of this section and section 7541 of this title. Such regulations shall provide that except where a different useful life period is specified in this subchapter useful life shall--

(1) in the case of light duty vehicles and light duty vehicle engines and light-duty trucks up to 3,750 lbs. LVW and up to 6,000 lbs. GVWR, be a period of use of five years or fifty thousand miles (or the equivalent), whichever first occurs,


Now, I am in no way an expert on Federal emissions law, and this analysis is in no way meant to be interpreted as an accurate opinion on Federal law regarding emissions, nor should it be taken as legal advice (I AM NOT YOUR LAWYER). However, I read the above sections to suggest that it is a crime to tamper with emissions devices only on new vehicles within a period of five years or 50,000 miles use after the date of initial import, manufacture, or sale. If that is the standard, then Federal law no longer applies to any slant six powered vehicle.

I am not going to take the time to research what the emissions laws are in Alaska, but, given the social mores of the population of that State, I would bet that a 1987 model year truck is exempt from testing, or only has to pass a sniff test. Heck, here in lefty-greenie Washington vehicles over 25 years old are exempt and we only do sniff checks.

Sorry Slant6AK.

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Casually looking for a Clifford hyperpak intake for cheap.

wow....that's a lot of regulation verbage.

I'm fairly certain that in Texas, once a vehicle is past a certain age, then it becomes exempt. I'll verify that....and then take the Valiant to the muffler shop and have them do catalytectomy.

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1954 Ford, Tudor Mainline
1976 Plymouth Valiant, 4 door


www.automotive-ninja.com

Not really. Those are only portions of several individual sections of the code. They are actually fairly concise and straightforward compared to other laws I have dealt with. You should take a look at some tax codes or some Supreme Court cases from the late 1800s. At least this statute is punctuated and has clearly delineated subsections. Heck, Washington State's DUI statute is a nightmare compared to these.
Just remember to check your State laws about removal of the catalytic converter.

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Casually looking for a Clifford hyperpak intake for cheap.

It used to be a muffler shop wouldn't remove a cat. I imagine it was due to liabilty issues. I told the guy at the exhaust shop that I thought the cat was plugged on my Aspen as the lack of tailpipe and holes in the muffler ought to be making some noise. He replied "you don't need that" and cut it out. It was plugged with carbon. My 75 Valiant will be losing the cat as soon as I do Dutra duals. I'm with everyone else about ditching the lean burn if possible. I am unsure about tranny as my 85 Ram that I converted was a manual.

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Thanks Mike

I may be wrong, but the way I understood the "cat" regs. It is/was not legal to remove/bypass/etc the cat from any vehicle that had one installed from the factory. The 50,000 mile 5year requirement made it necessary for the OEM to replace any failed emission equipment during that period, regardless of the OEM vehicle warrenty period. There is a stiff fine related to disabling any emision equipment, but does anyone know of it ever being applied to an individual vehicle owner? I would not worry about it, unless you are in a juristiction, that has MV inspection. I would, however, keep all of the parts, in case you wish to sell the vehicle into an inspection juristiction, or if regs are put in place for inspection in your area.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

ok...for Texas at least....here is what the Texas Dept. of Public Safety says in TX DPS Tranpsortation Code 548, Section 20.14:

"If installed as original equipment by the manufacturer, the catalytic converter will be considered a part of the exhaust emission system on all 1984 and later model vehicles."

So...for my 1976 model Valiant, it appears that I can remove the cat completely.....for a late model pickup.....it looks like the cat needs to stay (in Texas that is).

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1954 Ford, Tudor Mainline
1976 Plymouth Valiant, 4 door


www.automotive-ninja.com

This might very well be true. I did a quick search and couldn't find a case where an individual was actually prosecuted or fined for removing emissions equipment. Like I said, I am not an expert in this area.

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Casually looking for a Clifford hyperpak intake for cheap.