86 ram 50 2.0 5spd makuni carb starting issues

[Maximus]

Hi I've read posts on here that are similar to the issues my truck (Maximus) has been having. So here is the problem or problems truck ran and drove good just had warm idle problems popped out the exhaust. Figured why not let's get the carb rebuilt and since the clutch was basically gone having only one barrel working and fixing to both would surely finish it off so put that in while down my boss did carb while I did clutch. After those started perfect cold ran better warm and had better pull up hills just needed that fine tuning... Then wouldn't start let it sit at shop put fresh non ethanol in it and went to drive home again perfect cold drove half a mile and started bucking around couldn't drive out of second gear just wouldn't pull it. It died a few times I adjusted enough to get home barely. Next morning started cold perfect again waited till warm adjusted smooth shut off cause now couldn't engage clutch while running (A problem I will address after running). Went to start again 20 min later won't hit a lick here I am 2 weeks later drained tank gas is dead put new in ran like poo for 2 min then died tried adjusting and it tried to start but wouldn't then went to a backfire when letting off switch and now won't hit a lick again... Any help would be appreciated and I don't have the funds to put a Webber on it would be way easier.
Replaced items
Coil X3 to be sure
Plugs
Wires
Cap button

Spark was orange between all this.
Seems to flood easily
Start spray doesn't help even with fuel lines unhooked and carb drained/intake blown out.
Icm works can hear it click things when turning distributor
Fuel pump works filters good
Not sure if 3 solenoids are in the right places looked at pics on here for wire colors to try and match them up

[Maximus]

3 solenoids are on carb

[xboxrox]

3 solenoids are on carb

Check out my Mikuni rebuild photo album ~ a carb rebuild kit has new O rings for those solenoids ~ the factory 1987 OEM carb float fits the 1986 Mikuni ~ make sure no fluid is leaking into your float ~ check the small screen fuel filter around the needle seat make sure it's clean ~ see my photo album how to test needle seat for leaking by using a hand vacuum pump ~ hopefully your fuel system is clean tank filters lines etc ~ also hopefully all 4 cylinders test ok for compression & spark is timed correctly ~ make sure both air filters are NEW and that the Gas Cap will vent (not sure how to test a gas cap but they can cause problems) also make sure the wiring harness plug to the carb has clean contacts REMOVE any silicone if present & do not use silicone grease on any part of the spark plug coil wires as well ~ the 1987 vacuum advance diaphram unit fits your 1986 distribitor (it did mine anyway & can be replaced without removing the distributor)
Keep us informed of your progress, keep warm & take plenty breaks
GOOD LUCK

[geezer101]

A little test - when you get it running from cold and it dies on you, CAREFULLY check the ballast resistor on the ignition coil. If the thing feels hot, it may have failed (if it has failed, it will be hot enough to burn your fingers) Clues to a bad ballast resistor: will start and run when cold, dies when it gets hot and then will not start until the ballast resistor has cooled off (usually 15-20 minutes at the most) The ceramic insulator only needs the finest hairline crack in it for the ballast resistor to die. If you don't have a ballast resistor, the coil will roast everything downstream of it like the ICM in the distributor and cause premature burn out on the posts in the distributor cap and the electrodes on the plugs. If you have no spark it may mean the ICM in the distributor has failed - running a multimeter across it should read 50-200 Ohms if it's working. No reading or a high resistance value means it's got a fault.

[Maximus]

Thank you both I will check these soon we have been busy at work this week me and my boss are wondering if coolant is leaking into the intake and killing the gas so I'm going to clamp off my coolant line to intake and carb side blow everything out with air and spin over with plugs out then try starting bottle feeding this 36 year old baby

[xboxrox]

Thank you both I will check these soon we have been busy at work this week me and my boss are wondering if coolant is leaking into the intake and killing the gas so I'm going to clamp off my coolant line to intake and carb side blow everything out with air and spin over with plugs out then try starting bottle feeding this 36 year old baby

O'Reilly's rents a free combustion gas detector that fits onto the radiator cap opening ~ it will tell you if the coolant is leaking into the combustion chambers :^)

[Maximus]

It's not leaking from the head gasket so that won't help

[Maximus]

I should have been more clear on the water leaking in thought the gaskets from carb rebuild all look good I'm making sure there isn't a water leak in the carb causing the fuel to be diluted when/if it does fire up again

[Maximus]

I drove it every day before carb rebuild I only had rebuilt because it popped once warm hard cold start and second barrel wasn't opening but I could still drive it on 2hr one way trips to get parts for work so it has to be something from after rebuild I'd assume

[xboxrox]

I drove it every day before carb rebuild I only had rebuilt because it popped once warm hard cold start and second barrel wasn't opening but I could still drive it on 2hr one way trips to get parts for work so it has to be something from after rebuild I'd assume

I had the luxury (?) of the covid pandemic lockdowns to give me time to rebuild one Mikuni 32-35 DIDTF carburetor a Frankenstine of two carbs to make one that works fairly ok ~ ordering parts x ordering an extra carb x troubleshooting x having the disabled truck towed twice x breaking my original carb beyond repair x phone cons with Alan @ carburetion Technologies x etc x etc bull crap etc more BULL...

All I can do is wish you good luck for now... + in addition to a good carburetor, need good spark, ignition timing from idle to total advance gotta be spot on & compression a.k.a rings and valve timing gotta be good too + new air filters + no vacuum leaks + good PVC valve

This is a good start but not a complete fix for sure there is plenty more than could be wrong... GOOD LUCK

[Maximus]

Thank you. I know this thing is something else. I joke to everyone saying I'm ready to push it in a field on fire lol. So what I've ruled out so far.

Compression- good
Timing-dead on (checked 4 times now after spinning over noumerous times just like to make sure with timing.)
Fuel- bought a week ago catches fire out of hose to carb but hit and miss coming out side jet when you open throttle.
Spark- coil is new third one cause I thought it might be the problem. Resistor is good, new plugs, cap button, wires, icm is working got spark to all plugs and through all plugs still orange though...
Head gasket is good
Before the 2 min run with horrible idle cold start... It was cold starting great hit right when you turn key then bad warm idle I adjusted warm and running till smooth shut it off. Wouldn't start again...
I did pull carb after around 3 weeks of not hitting a lick. Adjusted to what I read on a thread here and that's when it ran for 2 min shaking like an alcoholics hand... I couldn't even keep screwdriver on long enough to adjust it then tried to start but wouldn't fully catch and run then to nothing first thing I do on it this weekend is pull carb and try to reset all adjustments from this site and start over.

[geezer101]

How much advance/retard on the distributor do you have? If you are maxxing out on either end just to get it to fire you will need to pull your distributor out and reset your firing order. Easy to do. Why this happens? No idea, but I got caught with this a long time ago.
Spent 4 hours diagnosing it and burnt through most of my patience in the process :cussingblack:

[xboxrox]

Well Maximus ~ there are 3 stages of ignition timing 1) Initial @ idle RPM refer to the lable on the hood 2) Vacuum advance which can be seen happening with a bright timing light 3) Centrifigal which happens as the RPM increases which again can be observed with a good timing light ~ total advance I think is in the high 30°

The timing mark is a TINY (extremely small) V notch in the crank pully on the LIP closest to the timing cover ~ paint it white

My carburetor still has the California Anti Tamper Plug in place over the AIR/FUEL idle mixture screw ~ adjusting this screw will help smooth idle ~ my mechanic friend adjusted this screw on a junk yard carb I had on the truck and it ran perfect ~ wished I had that carb on the truck again OH WELL sheet happens..!

The (8 PIN?) main wiring harness connection at the carburetor MUST be squeeky clean MUST not have ANY traces of silicone grease on those pins ~ spark plug wires coil wire SAME THING must not have ANY electrical silicone grease on those connections..! TRUST ME BEEN THERE AND DONE IT

Squirt some quality silicone spray onto the choke plate pins to ensure to moves smoothly..!

USE new air filters in the air cleaner there is a 2nd small one on the case side change it too Rock Auto had one for me

Member 85Ram50 gave me his engine starting procedure which works perfect on my truck too ~ COLD ENGINE press accelerator to the floor ONCE ONLY then start engine (my truck still idles a little crappy for a minute or two when cold even in Hawaii 70°F temps ~ HOT ENGINE press and hold open the accelerator pedal 1/2 or more to the floor then start engine

Make sure the PVC valve is clean and works properly (a one way air flow)

Assuming all the above is done AND your truck's fuel system is clean with fresh 87 octane and your fuel pump is not weak AND the computer ecm works ok O2 sensor & carb solenoides are ok then your truck should start & run pretty average to pretty well

??? Keep tweeking, head scratching & fixing ~ if you have an FSM then refer to the Troubleshooting pages for engine running problem pages

geezer is right..! MAKE SURE the spark plug wires are attached in the proper firing order AND THAT the distributor rotor is pointing near the #1 wire when the #1 piston is at TDC on the compression stroke and the crank pully V notch is pointing near the 0 zero timing cover mark

Adios
George

[geezer101]

A tip - give the innards of your distributor a blast of WD40. I have found the advance plate can freeze up which causes advance lag and restricts vacuum advance. You want it to be smooth and responsive. It sounds like it wants to run but the timing is off just enough for it to fight you.

[Maximus]

Hi all quick update pulled the carb back off. I got it re adjusted to spec based off what I've read on here. 3 solenoids on carb hooked to correct locations thanks to xboxrox pics thank you. Distributor is dead on tdc and wires are in correct order. On hooked fuel line to try and start with spray still nothing so I'm taking it back to shop this morning just loaded it on the trailer yesterday so me and boss man can work on it at the shop I will post update soon hopefully with what is wrong. Thank you all for the advice and help .

[xboxrox]

Hi all quick update pulled the carb back off. I got it re adjusted to spec based off what I've read on here. 3 solenoids on carb hooked to correct locations thanks to xboxrox pics thank you. Distributor is dead on tdc and wires are in correct order. On hooked fuel line to try and start with spray still nothing so I'm taking it back to shop this morning just loaded it on the trailer yesterday so me and boss man can work on it at the shop I will post update soon hopefully with what is wrong. Thank you all for the advice and help .

Sh____T
You have an original mechanical fuel pump? Could the problem be not enuff fuel?
Sux but good luck

[Maximus]

Yea pretty much stock everything we have been slammed at the shop so we didn't start on it yet... Missing this truck a little lol

[Maximus]

Ok update sorry it's been a while it's running out another set of plugs in and pinched fuel line started right up when you let fuel line open it is getting way too much fuel we put a regulator on the line at 1psi it runs and drives but still loads up on start and it's giving too much when warm we're thinking either aftermarket pump and or the fuel needle we got in rebuild kit isn't seating and is just letting it flood out any thoughts? Also if you switch the fuel lines it will idle all day you just can't drive starves it out so I either get too much the right way and not enough the other

[Maximus]

Fuel needle in AutoZone rebuild kit is double the size caused it to flood and foul plugs just gotta adjust it now crazy how it can be something so small

[geezer101]

Good spotting on that, but Autozone... :slap: AFAIK fuel needle and seat is universal across 32-35DIDTA Mikuni carbs.

[xboxrox]

Dang carburetor well at least you boiled it down to a fuel issue ~ I bought two Mikuni rebuild kits and the needle seat were same as what was in the carburetor ~ FYI a Mitsubishi Mikuni 1987 float should work in your 1986 carb ~ I disassembled a 1985 & 1986 Mikuni and the 1987 float was same same SO I DID NOT use the aftermarket strange looking float ~ well, make sure you have the proper float adjustment PLUS while the carb top is off DO A TEST with vacuum to ensure the needle seat holds ~ apply vacuum to the fuel inlet nipple while holding the carb top cover assy UPSIDE down

Fix it :)

[Maximus]

I might have just gotten the wrong needle in the kit I have to take this one out again so I will take a picture. I used original float back in it not sure how that would be adjusted...? When we try and fine tune it it randomly starts a stream of fuel out of the barrel jets or it just doesn't get any fuel. We're deciding if a new carb or putting aftermarket on would be better or if making a carb conversion plate or getting a kit... Whatever would be cheapest cause I don't have alot of money to spend on it. Around here it's 500 for new carb and I'm not sure what aftermarket I can put on it's a g63b 5spd any thoughts on my best option in the long run?

[Maximus]

Also AutoZone claims they can't get just needle and seat and napa wants 38 with shipping for it lol. I bought whole kit from AutoZone for 20 lol

[geezer101]

A 32/36 Weber kit is cheaper than the correct OEM replacement MIkuni (if they exist and it's not just another garbage refurb...) There are so many Mikuni 32-35DIDT variants that getting the wrong one is easy and I have a suspicion that most of the resellers don't know the difference. Things to be aware of when going down the Weber path - there are other parts etc that need to be factored in. An electric fuel pump (HVLP pump that has 3.5 psi max pressure and can handle 42 gallons per hour flow), add a relay and fuse to protect it, coolant barb delete for the OEM carb as it has a wax pellet choke and deletion of EGR and emissions junk (can be left just to make it appear to be functioning) And you will need to spend a bit of time experimenting with the ignition tune to get near optimal performance (or you can get the mechanical distributor advance modified by a shop that knows what they're doing - or try to DIY...)

[Maximus]

Hi all been a while since ive been on this site finally have time to work on the truck again so to update everyone got third rebuild kit in truck started and idled perfectly for 15 min then died and i couldn’t get it to spin over even by hand no.1 connecting rod bearing spun due to mechanical fuel pump failure was pushing fuel into oil so replaced all bearings put new timing belt kit on and aftermarket electric fuel pump now when i get it to start I can get it to either run at idle or when i feather the gas i think i might need help with wiring fuel pump and what hoses to to be hooked up as it has 2 on front and return on side

[xboxrox]

Mechanical fuel pump diaphragm musta split cracked torn and let fuel dilute the crankcase eng oil BUMMER Several years ago my truck began losing power so my local mechanic replaced it with an O'Reilly's same as original mechanical fiel pump ~ it worked and the truck ran fine again (no more starving for fuel) My truck also experienced dying from running too rich ~ I eas damn lucky spotting the carburetor float was about 1/3 full of gas that leaked into it causing the float to be too heavy to rise up and close the needle seat valve ~ I recommend installing a new mechanical fuel pump & a new float too ~ TEST the needle seat before reinstalling the carb ~ youtube vids showed me how using a hand vacuum pump
Will say a Prayer for you, honest me & wiafu will pray you have success..!

Aloha & Keep Up the Good Fight
P.S. The Japanese built it so it should work LOL

[xboxrox]

http://www.mightyram50.net/vbulletin/album.php?albumid=604&attachmentid=25870

[xboxrox]

MY PHOTO ALBUMS HERE (4 ALBUMS of MIKUNI REBUILD) (http://www.mightyram50.net/vbulletin/member.php/3998-xboxrox)

http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=28055&d=1698909692

http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25897&d=1605138168

http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25870&d=1605078514


MAKE SURE YOUR FLOAT HAS NO LEAKS & NO FLUID INSIDE ~ A SLOW LEAK IS ESPECIALLY INCIDIOUS AND HARD TO DIAGNOSE BECAUSE THE ENGINE MIGHT RUN FINE FOR A LONG TIME (DAYS, WEEKS, MONTH) BUT THEN SLOWLY HAVE LOSS OF POWER SYMPTOMS THEN BEGIN DYING TOO...

Good Luck