1991 Surf (2lte) really slow

[Jemjem787]

Hey guys, just as a forewarning this is my first rig/mechanical project so I'm pretty inexperienced with most things.

I bought a surf about 4 months ago, and when i drive it on the highway i can only get between 100 and 105 km/hr (60mph) on flat ground while driving. I thought this was normal for a vehicle like this as i have a buddy who has some really slow landcruisers. However i've been driving and talking with other surf owners (Same year same engine) and they can get upwards of 140km/hr. So I'm thinking there is something wrong with mine.

Mine is a 5spd, has a 2.5" lift with 31" tires. The EGR and Throttleplate have been deleted (Was told the deletion was kind of hacked though), everything else is stock.

I don't have a lot of history with it, so my first plan of attack was to change out the fuel filter and see if that did anything, however i want to see if anyone else has some advice first. Anyone have input on my problem? Thanks!

 

[brownbear]

a few things are needed for guys to help.

At 100 or so, what is your RPM, you are in 5th gear?

Does it accelerate up there normally? Sluggish all around?

At that speed what's it feel like? Like it's rev'ing like mad or bogged right out?

Also is it smoky out of the tail pipe?

 

[Jemjem787]

a few things are needed for guys to help.

At 100 or so, what is your RPM, you are in 5th gear?

Does it accelerate up there normally? Sluggish all around?

At that speed what's it feel like? Like it's rev'ing like mad or bogged right out?

Also is it smoky out of the tail pipe?

I'm in 5th gear around 3000 RPM

The Surf is generally slow to accelerate vs something like my toyota matrix.

The revs cap out at 3k RPM

It's smokey at startup but it dies down after a while. The surf is currently in the shop for unrelated reasons and i'm getting the glow plugs swapped as the mechanic noticed they were about due (And 1 was completely dead). But AFAIK glow plugs are only for starting?

 

[RufusTheDufus]

I've got an 84 Hilux with the 2LT (not LTE). A dragging rear brake caused similar performance issues for me.

 

[GTSSportCoupe]

What year is your surf? Wondering if it's the 2LT-II or 2LTE (mechanical or electronic injection). 1989 and very early 1990 were mechanical. This would help direct a troubleshooting approach. If you're not sure, just post a picture of your engine.

Also, you should get yourself some gauges. Definitely a boost gauge and pyrometer to start. This will tell you if your turbo is on it's way out (low boost), or if your air/fuel ratio is out (lean - no power). It'll also help you tune your engine for best power/efficiency.

A temperature gauge is also a good move with these trucks, as the factory one has a deliberate dead zone. You could also just fix the dead zone by following these instructions: Temp Gauge Mod

These old vehicles are projects and will likely need lots of care and maintenance to keep reliable and running well. Unless you're rich, you might have to learn how to do some of your own wrenching.

 

[Jemjem787]

I currently have a turbo gauge installed. It was a cheaper gauge, but I recall getting boost around 1400 rpm (4psi) and maxing out at 9psi at 3k rpm.

It's a 1991 LN130 2lTE for sure, I have electronic fuel injection.

I have plans for installing an egt gauge and a water temperature gauge as well and I've already completed that temp gauge mod.

As for the rear brakes dragging, what's the best way to check this?

Also yea I understand that these older vehicles require wrenching of my own. I do most of the work myself (it's only in the shop for some specialty s***)

Thanks for the help.

 

[brownbear]

If it's on a lift and in neutral you can try spinning the rear tires by hand. If the brakes are on even a little you will hear it rubbing, and it will be hard to turn. You can also do this with jack stands on the ground. Be safe, chalk the front tires when lifting the rear.

 

[Jemjem787]

If it's on a lift and in neutral you can try spinning the rear tires by hand. If the brakes are on even a little you will hear it rubbing, and it will be hard to turn. You can also do this with jack stands on the ground. Be safe, chalk the front tires when lifting the rear.

As I'm not in possession of the vehicle right now I can't check, but I've done that before and I've never heard any squeaking or rubbing

 

[brownbear]

Another sign to see if they are rubbing is heat. You can use infrared thermometer. See what the temps on the drums are side to side. Also maybe the parking brake isn't releasing fully. If you went for a drive for ten minutes (like a highway) and then coasted to a stop or with minimal braking I would not think there would be any heat on the drums. It would be very low, not burning to the touch. but if the brakes are dragging they would be extremely hot.

Also when you're driving and you go into neutral to coast, does the vehicle decelerate quicker than you would think it should? If it feels like it slows down quicker than a 4500 lb vehicle should, it may be dragging.

Okay brakes aside.

5th gear and 3k rpm at 100 km hr seems like high rpm for that speed. Maybe others can chime in who own this engine. I would think in 5th you would be around 2000-2250 rpm. So that makes me think it's geared higher in the diffs...? But it would accelerate well if that was also the case.

What is the engine redline? My 3b is like 4k rpm. I can free rev it to this, or hit it in first and second very easily. I typically don't go over 3000-3500 rpm.

Can you free rev (neutral) to your red line?

 

[GTSSportCoupe]

OK, a common thing that kills power on these is the vacuum hose to the boost sensor comes apart. This means no extra fuel as the boost comes on (boost compensation). There are two separate systems on a 2LTE. There are vacuum lines connected to the vacuum pump on the alternator (to control emissions and the T-case), and there are boost lines connected at the intake manifold that run through a little filter and to the boost sensor. Don't confuse the two systems or connect them together.

Basically make sure the boost hose from the intake manifold (just above where the EGR enters the intake manifold) is connected via the little filter to the boost sensor. Make sure it has not popped off anywhere.

Also, check the little cap on the injection pump on top of the spill control valve. If it's off it means someone has messed with the injection pump fueling.

 

[Jemjem787]

Thanks for the help GTS, Brown, and Rufus. I will try everything you guys have talked about reply back if it fixed it or not. Thanks!

 

[AirheadNut]

Not sure what gears the Surf came with, but I’ve got an LN106 Hilux and it has 4.30’s. My manual Prado with 4.88’s did a touch over 3k at 100, and around 3300 at 110 with stock 225/75R16 tires. Your gearing sounds about right, maybe slightly under geared.

 

[Jemjem787]

Not sure what gears the Surf came with, but I’ve got an LN106 Hilux and it has 4.30’s. My manual Prado with 4.88’s did a touch over 3k at 100, and around 3300 at 110 with stock 225/75R16 tires. Your gearing sounds about right, maybe slightly under geared.

I had that suspicion but I am hoping it's just an issue with the vehicle that i can fix rather then it being under geared. I haven't checked my gearing yet but is there any sort of formula to calculate top speed/acceleration with knowing the gear ratio/torque/hp?

 

[John in Utah]

Find your axle and transmission codes, then you can calculate what your engine rpm at speed should be and see if it’s close to what you actually experience. If not you know someone has messed with your gearing. For example my axle code is G285 = 4.30:1 and my trans code is G52 = 0.851:1 5th gear. With ~30” tires that’s 110 kph at 2800 rpm.

Granted I have the slower 3L, but these are not fast trucks in stock form. I usually don’t go much past 110 kph on the highway. Is it possible your buddies are running loads of boost and fuel over stock?

 

[roscoFJ73]

Too make sure your injection pump has the correct output, you can flatten it in neutral and it should reach 4000-4200rpm. Check the manual for the exact rpm. I think its in the injection part.

 

[Jemjem787]

Too make sure your injection pump has the correct output, you can flatten it in neutral and it should reach 4000-4200rpm. Check the manual for the exact rpm. I think its in the injection part.

I no longer have the manual,

To everyone else, thanks for the help. I will do everything listed and get back to you once i am done with my results.

 

[4Ruster]

Old thread I know I know, but did you ever figure it out?