Nemo_hohz

Hi I own a 85' turbo efi pickup with an aftermarket turbo , the truck starts to bog out at 8psi of boost or when I run the truck for a long period of time it bogs out when the turbo comes on, it seems like the airflow sensor isn't good cause she doesn't fully rev , all the owners before me couldn't figure out the problem , the pervious owner put an anftetmarket turbo after that previous owner tried to rebuild the motor but couldn't and didn't put the turbo back in but was running the truck without the turbo in, long story right ? Well someone must have had the same issue as me somewhere , hopefully someone on here can help 😭

nothingbetter

Sounds to me like its poorly tuned with an aftermarket turbo. I hope you like tinkering and spending time under your hood.

If it runs fine off boost, then runs like crap when on boost I'd say its a fuel issue. Either rich or lean will cause that. If your going to start playing with boost, don't risk wrecking your engine and get a wideband AFR gauge. That will tell you where you stand with fuel. And tune from there.

How you tune is up to you. I'm running an Apexi SAFC and it does the job, although a bit old school. Can likely be had for cheap used online. I'm not sure if its compatible with your engine though. Lots of other options too.

It could also be your timing not adjusting itself correctly once it hits boost.

Does it have the turbo cams in it or is it a factory 22re with the turbo parts bolted on?

It could also be a bunch of other things.

If you don't want to start pouring money into it to make it run properly with aftermarket parts, get a factory turbo to put back on, or do like the last guy and sell it.

nothingbetter

I'm assuming you have a 22ret. Unless your from somewhere else in the world and your running a diesel?

Since that engine was only an option in 86 and 87, How clean does the swap look? a hacked together wiring harness (if needed) could be causing all your problems.

Nemo_hohz

I'm not sure , it's a stupid problem that I can figure out , the wiring is All ˟˟˟˟ , it's all birdnest , but ima try swap turbo setup and maybe see if the after market turbo is ˟˟˟˟

Nemo_hohz

Its a stock 85 original turbo , but the turbo itself isn't original it's a aftermarket , but i revs to 7k and when the turbo turns on she starts to bog all, I think all the motor components are stock for the original turbo , but in running a slightly bigger turbo , would it matter if I put a stock turbo back on? Could it be the computer ?

nothingbetter

I don't know much about that engine but I know a little bit about turbochargers. If my assumption of a fuel issue is correct, then YES, it is the computer that's at fault but there's nothing wrong with the computer. Its tuned for the factory turbo assuming you have the proper computer. Its not tuning fuel properly for the aftermarket turbo and making it run like crap under boost with different lag time, timing requirements and pressure levels.

You can't just throw a bigger turbo on, double the boost and expect to see more power. Swapping the turbo is the easy part. Its tuning the engine after the turbo swap and all the other costs that get expensive and time consuming. Which is why the PO didn't do it. Expensive and time consuming. Once again get a wideband AFR gauge and go from there.

Now onto other topics. Now you say the wiring is a birdsnest which makes the think it wasn't a factory turbo. Why would someone hack a harness for the stock engine? The turbo engine was only a factory option in 86 and 87. You claim to have an 85. Maybe you have an odd ball that got pushed out of the factory late in 85. Do you have IFS or a solid front axle? Check on your fire wall. There will be a metal plate riveted on near the cowl that will tell you what engine came in it from factory. Check that to see which engine the truck had from factory. Check that you have the proper computer for the engine. I'm assuming the turbo model uses a different computer.

If the engine was swapped, is there a different fuel pump between the turbo and n/a model to supply the extra fuel needed under boost? Maybe you're running out of fuel. I'd change the fuel filter so I know its not impeding fuel flow. Consider getting an adjustable fuel pressure regulator and a high flow pump just to be sure. The engine been dug into, you need to KNOW whats inside, not just think you know. Whats the compression ratio? Factory pistons or aftermarket? Has the head or block been decked? What thickness of headgasket? Better check what injectors they put in. What kind of AFM is installed? How is the engine timing? Hows your fuel curve? Which cams are in it?

My point with that paragraph is to show the world of turning up the boost is a complicated one. So many variables to consider. Without knowing the history of the engine its going to be hard to get it dialed. All the above factors will effect the amount of boost your capable of pushing.

Once again, Get a wideband AFR gauge. Without it you can't tune at all and you'll fry your engine.

1980lwb

Was this ever figured out? I have an 85 turbo motor also. Stock motor that was swapped to a 4runner. I have a hard start all the time with smell of raw fuel. I have good power also until the boost kicks in and then it bogs out.