89 2.0 running poorly

[koboldwrangler]

Hello--

I am posting for a friend I am trying to help, so bear with me if I get something wrong.

He has a '89 d50 with the carb'd 2.0 w/ auto. The truck does not want to idle smoothly -- bucking and shaking -- and revvs slower than molasses until the motor is warm. You could literally hold the throttle wide open while its cold and it would take a solid 5 seconds to rev up to a decently high rpm. I only let the truck get mildly warm before telling him to shut it off, but before he did, I gave it a few solid revs and it seemed to be getting better.

Basically the parts cannon has been blasted at this truck -- new dizzy, fuel filter, pump, wires, plugs, coil, and a weber 32/36 kit. I was asked to help after most the parts were installed and was there to help with the 32/36 install.

Seeing as all the emissions crap has now been disabled, the spark system is essentially new, and the fuel system has been gone through, I really dont know what else to check.

I dont know a bunch about these trucks. My next thing to check would be valve tolerances but I am unsure if his had the adjustable lifters or the HLA's. I know the 2nd gen(?) trucks had hydraulic lash adjusters, but I am unsure what gen his truck is.

My next concern is either a timing belt issue or compression. His timing was set a bit high, but that shouldnt affect how it revs based on the motor temp. It does burn oil while idling, which makes me think the motor is tired...

Could the torque converter be causing issues?

Any help would be really appreciated. Hes about to burn the truck to the ground with the issues hes having with it haha

[geezer101]

Hi and welcome to mightyram to you and your buddy. Bunch of things could be up with this - Weber isn't set up properly, or it's a knock off Weber/clone, ignition timing is off a little etc. If the valvetrain doesn't sound like an old typewriter and the adjusters haven't been over adjusted it won't affect general running/idle. The manual lash adjusters need to be done hot and by feel. You will not get a lot of luck from going 'by the book'. There is a subtle art to it. Biggest culprit to burning oil is bad valve stem seals. If the transmission is engaging properly and he's getting all gears AND the kickdown cable has been connected you can disregard the trans as being the fault (there is a specific install kit for auto) Idle RPM has to be a little higher on an auto so it doesn't lug when drive is engaged (not enough to slam the rear diff when you shift it though) Look up the Weber install threads. They will be helpful to review your install and adjustment.

[koboldwrangler]

Hi and welcome to mightyram to you and your buddy. Bunch of things could be up with this - Weber isn't set up properly, or it's a knock off Weber/clone, ignition timing is off a little etc. If the valvetrain doesn't sound like an old typewriter and the adjusters haven't been over adjusted it won't affect general running/idle. The manual lash adjusters need to be done hot and by feel. You will not get a lot of luck from going 'by the book'. There is a subtle art to it. Biggest culprit to burning oil is bad valve stem seals. If the transmission is engaging properly and he's getting all gears AND the kickdown cable has been connected you can disregard the trans as being the fault (there is a specific install kit for auto) Idle RPM has to be a little higher on an auto so it doesn't lug when drive is engaged (not enough to slam the rear diff when you shift it though) Look up the Weber install threads. They will be helpful to review your install and adjustment.

Hello--

So we have the kit set up correctly, and the trans is all connected. He bought the redline kit, so it should be a jetted correctly for his truck, and its a legitimate weber as all the webers ive messed with with my toyotas, have been clones.

I am leaning towards tight valves. The one thing I cannot find and was hoping to learn here before removing the valve cover is, does it have adjustable valves, or does it have HLA's. That would make the most sense to me as when its cold, the tolerances are too tight, holds the valves open and compromises its compression....and as it gets warmer, the tolerances loosen up, raising the compression back up.

If it does have adjustable valves, what are the tolerances? I think I read somewhere .005/.007 hot, and .004/.006 cold?

Thats kinda what I thought with the oil burning. Though, what I thought was interesting was it seemed to start burning only once the engine started to get warm. Usually the valve stems seals only allow it to burn oil on startup.

[geezer101]

Are you using a HVLP electric fuel pump? The factory mechanical pump will overpower the float needle and cause running issues, and installing a regulator will eventually kill the pump. I think it should still be using mechanical adjusters even though it's an 89 build. Pull the cover and inspect it as it's the only way to be sure. Really simple job on the G63B engine. HLA's will never cause clearance issues. The rings could be gummed up so doing something like an oil flush may help free them and reduce the oil burn.

I found the clearances online for the 2.6 so there shouldn't be much difference (source was 4x4wire on the Pajero/Montero 2.6)

Recommended hot clearance for intake is 0.15mm/exhaust 0.25mm (0.006/0.009...ish) How I set them is turn the cam so the rocker being adjusted is off lobe, back the adjuster off so it's free and then adjust it til you feel minute play in movement, lock the adjuster up, check then re-adjust if it has closed the clearance during locking the adjuster and recheck. Rocker arms and rails wear and feeler gauges become a grey area due to small variations in wear etc. Procedure has to be done hot.

[SubGothius]

2nd-gen trucks are '87 on, so yours is a Gen 2.

US-market '85-on 2.0L engines should have hydraulic lifters, so only the jet valves would need manual adjustment: 0.010" clearance on a hot engine.

That said, jet valves are nonfunctional with a Weber swap, so you may as well just remove the jet valve adjuster screws entirely -- or even replace the jet valves with a "jet valve eliminator" kit, as damaged/stuck jet valves could also explain the poor-running problems you've described.

[koboldwrangler]

2nd-gen trucks are '87 on, so yours is a Gen 2.

US-market '85-on 2.0L engines should have hydraulic lifters, so only the jet valves would need manual adjustment: 0.010" clearance on a hot engine.

That said, jet valves are nonfunctional with a Weber swap, so you may as well just remove the jet valve adjuster screws entirely -- or even replace the jet valves with a "jet valve eliminator" kit, as damaged/stuck jet valves could also explain the poor-running problems you've described.

Hmm, I will look into this. How would I be able to tell if it has a bad jet valve without buying the kit? I think he's at the point of not wanting to buy parts unless we know it will fix his issue.


Are you using a HVLP electric fuel pump? The factory mechanical pump will overpower the float needle and cause running issues, and installing a regulator will eventually kill the pump. I think it should still be using mechanical adjusters even though it's an 89 build. Pull the cover and inspect it as it's the only way to be sure. Really simple job on the G63B engine. HLA's will never cause clearance issues. The rings could be gummed up so doing something like an oil flush may help free them and reduce the oil burn.


He's using a basic clicker pump with a holley fuel pump regulator. Fuel isnt the issue here as he was having the same exact issue with the mikuni carb.

[koboldwrangler]

Are you using a HVLP electric fuel pump? The factory mechanical pump will overpower the float needle and cause running issues, and installing a regulator will eventually kill the pump. I think it should still be using mechanical adjusters even though it's an 89 build. Pull the cover and inspect it as it's the only way to be sure. Really simple job on the G63B engine. HLA's will never cause clearance issues. The rings could be gummed up so doing something like an oil flush may help free them and reduce the oil burn.


He's using a clicker fuel pump with a holley fuel pressure regulator, so fuel isnt the issue here. It's been having this issue even with the mikuni carb.


2nd-gen trucks are '87 on, so yours is a Gen 2.

US-market '85-on 2.0L engines should have hydraulic lifters, so only the jet valves would need manual adjustment: 0.010" clearance on a hot engine.

That said, jet valves are nonfunctional with a Weber swap, so you may as well just remove the jet valve adjuster screws entirely -- or even replace the jet valves with a "jet valve eliminator" kit, as damaged/stuck jet valves could also explain the poor-running problems you've described.

I know a compression test is in order, but how would I tell the difference between a bad jet valve, cracked head, and a blown head gasket? All seem possible at this point, and I dont want to pull the head unless we know that is the issue.

[geezer101]

You can visually check the jet valves and see if any of them aren't returning to full extended height by removing the rocker cover. These things work, but when they don't they really mess the engine up. As SubG has stated, the jet valve system doesn't work on a Weber swap as the auxiliary intake galleries are blocked off by the base of the Weber carb. The jet valves can be removed and the eliminators can be installed without taking the head off. The other issue with jet valve heads are cracking around the jet valve in the combustion chamber roof. An iron/steel insert in the middle of the weakest part of an alloy combustion chamber that expands at different rates. Great idea...