2.9L Reality Check: Highway capable?

[eightynine4x4]

I mean, isn’t there a chance that my serious loss of power up hill has nothing to do with air flow or exhaust? Couldn’t it be just that multiple things are out of spec and slacking in the engine and it needs some degree of rebuild? Or maybe something(s) is just plain bent? Maybe I should do a compression check or a leak down test. Or maybe I should pop the covers this weekend and evaluate.

 

[Uncle Gump]

Separate the convertor from the exhaust... take if for a rip and see what happens.

I will admit I'm a bit rusty with some of these things... I just don't use it everyday like I use to. But while driving and holding a steady throttle... you should have vacuum... just like you did while sitting in park.

 

[ericbphoto]

Have you checked for fault codes? The ecu might give you some clues.

 

[eightynine4x4]

Have you checked for fault codes? The ecu might give you some clues.

Not since last summer and I think my codes were only sensor issues which I believe are resolved. I’ll give it another shot though.

 

[ericbphoto]

Not since last summer and I think my codes were only sensor issues which I believe are resolved. I’ll give it another shot though.

Might be a good idea. And, just because it says "sensor XYZ reports blah-blah condition" doesn't mean the sensor is bad. The sensor is most likely good and telling you that something else is wrong which causes that condition.

 

[RonD]

+1 ^^^

ALL CODES are sensor codes, lol

Computer can't know if a spark plug is bad or an exhaust valve is leaking or a fuel injector is clogged
It can set a misfire code or a Lean code, that's all

These Codes would come from distributor sensor or O2 sensor, doesn't mean sensor is bad, in fact it usually means sensor is working because computer can use it to detect a problem
So "don't shoot the messenger"
90% of all sensors replaced by DIY were working fine

Sad thing is 50% of replaced sensors by Professional Mechanics were working fine
But that's usually done to pad the bill, but can be from laziness and ignorance

 

[eightynine4x4]

+1 ^^^

ALL CODES are sensor codes, lol

Computer can't know if a spark plug is bad or an exhaust valve is leaking or a fuel injector is clogged
It can set a misfire code or a Lean code, that's all

These Codes would come from distributor sensor or O2 sensor, doesn't mean sensor is bad, in fact it usually means sensor is working because computer can use it to detect a problem
So "don't shoot the messenger"
90% of all sensors replaced by DIY were working fine

Sad thing is 50% of replaced sensors by Professional Mechanics were working fine
But that's usually done to pad the bill, but can be from laziness and ignorance

Haha, right. Yeah I meant that the codes were saying some things were way out of range and then after some research and evaluation of the sensors, all logic pointed to a couple sensors being actually bad. Like for example my O2 was a rust barnacle. I’m pretty sure I did multiple code pulls after and that there were no issues anymore but I could be wrong and maybe one was lingering. I really need to start keeping a repair log. I’ve had so many other more urgent matters to address for actual life safety, like stalling while sitting in an uphill stop and major suspension issues, and to be honest the fact that I’m now really able to dive into engine performance means I’ve come a long way with this truck!

Will report later with code readouts…

 

[RonD]

O2 sensors use a chemical to detect oxygen in the exhaust, they run out of that chemical after 100k miles or 12 years which ever comes first
These are the only sensors that have a limited lifetime, like batteries and tires they have a limited lifespan

 

[eightynine4x4]

New codes! How exciting! Never got these particular numbers before.
This is just the KOEO set of codes for now. I’m still sorting through the secondary step of testing computer control of ignition timing and then can do the KOER test.

KOEO:

86 O: Adaptive fuel limit reached or 3-4 shift solenoid circuit failure
— code 10 buffer —
96 C: Fuel pump secondary circuit fault / high speed fuel pump relay open

ummmmmmm. Am I just lacking fuel in high speeds and bogging???
I didn’t even know a secondary fuel pump existed.

 

[fastpakr]

I thought an '89 only had a single in tank high pressure pump, but could definitely be mistaken. Easy enough to rent a fuel pressure gauge and do some testing.

 

[eightynine4x4]

I thought an '89 only had a single in tank high pressure pump, but could definitely be mistaken. Easy enough to rent a fuel pressure gauge and do some testing.

I’ve already installed a new fuel pump and fuel regulator and have tested the daylights out of fuel pressure while doing so. Tons of pressure at pump output and good regulated pressure where it should be. This is how I got the truck to stop stalling while at uphill standstills. Been great ever since.
Is there some higher speed switched on device for sending more fuel or something?

 

[fastpakr]

Sorry, I haven't kept up completely with the thread and missed that you'd done all that.

If you can lay your hands on a Mitchell manual for the '89, it will have a clear sequence of tests to run to chase down any code. Definitely takes a lot of the guesswork out of it.

 

[eightynine4x4]

Sorry, I haven't kept up completely with the thread and missed that you'd done all that.

If you can lay your hands on a Mitchell manual for the '89, it will have a clear sequence of tests to run to chase down any code. Definitely takes a lot of the guesswork out of it.

Thanks! I’ll try to find that. Did some quick searching but their site is no longer there and anything else that pops up is the Haynes which I have and it doesn’t have code stuff.

Will post some KOER codes soon..

 

[fastpakr]

Thanks! I’ll try to find that. Did some quick searching but their site is no longer there and anything else that pops up is the Haynes which I have and it doesn’t have code stuff.

Will post some KOER codes soon..

MITCHELL 1989 DOMESTIC LIGHT TRUCKS & VANS SERVICE & REPAIR MANUAL 20JS-1268-M12 | eBay

Find many great new & used options and get the best deals for MITCHELL 1989 DOMESTIC LIGHT TRUCKS & VANS SERVICE & REPAIR MANUAL 20JS-1268-M12 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

That's what you need.

 

[eightynine4x4]

From poking around what others have figured out from the secondary fuel pump code, since it’s a C code from the trucks memory, it could just be that it detected recently that at some point the fuel pump was disconnected. A couple rides ago I did in fact depressurize the fuel by way of removing fuse and running truck. I was changing the fuel filter. So this code could disappear soon.

I haven’t figured anything out about Adaptive Fuel Limit Reached yet though (or if it’s shift 3-4 solenoid)