Ok I don't get on the forum much but I have a little issue. My car is an 88 t2 with an s5 motor and trans and s4 electronics.complete emissions removal. 720 secondaries with and ecu r tek chipped. and a walbro 255. Start the car, let it idle for a few and go drive it. Drives fine And pulls hard for 10 mins or so then has no power really or acceleration. I turn the car off and right back on and runs great again no problem but just for a few. HAs good compression,clean fuel filter, good plugs, no vaccuum leaks,great oil pressure. Any ideas

 

Needs an adjustable fuel pressure regulator?

 

Not sure

 

The FSM shows a way to check the AFM. Perhaps the internal temp sensor is at fault. Also check the Water Thermosensor. W/key to on, Pin 2I measures 2 to 3 volts cold and .4 volts fully warmed.

 

Your fuel pump is dying.

 

Sounds legit.

Might as well check everything satch mentioned and go through process of elimination

 

It's got a brand new water temp sensor and a brand new walbro 255

 

We're talking about the connection to the sensors being received at the ECU and not whether the sensor is new or not. A poor connection would render the sensor useless regardless of its age. There are different temp sensors, Thermosensor is behind the water pump. The other sensor I speak of is inside the AFM. There are other temp sensors on the car as well.

 

oh, thanks for the info. a few other questions. Would the Walbro 255 be pushing too much fuel than it needs? Also, i do not have the stock electric fans connected. Would them being disconnected make any issues?

 

Electric fan would not be an issue. You can search to see what other turbos use but I think yours is okay.

 

Ok cool, this is very annoying.... its a long story but i blew my stock t2 motor which is why ive got the s5 block in it. i sold all my wiring and sensors and bad motor and trans. I ended up getting most of it back. Except the AFM which i got a used one from someone on here. Not a hundred percent sure it was for an 88 t2..

 

So if it is the wrong AFM what would the car do..

 

It'll run rich or lean. TII to NA =rich and vice versa.
You could try pull off the AFM and feel the tension on the flap door if it is smooth and there is some resistance. Check valeues from FSM on AFM. Try back probe the ECU and check values.
A bad fuel pump will cause that as well. I'd pull it out and check. You do know there's fake Walbros out there right? Just cause it's new I wouldn't bypass it. Fake or not.

I think it comes down to AFM or fuel pump. You're not blowing fuses so obviously not grounding problem. Other sensors will either cause hesitations. Something is shutting off fuel.

 

Ok guy got a junk yard afm And put it in and nothing. Car wouldn't stAy running. Went to Oreilys and got a reman afm and did the same thing. Put the old one back in a the car revs freely in neutral and drives the same still though

 

I'm hoping after I get the air fuel right and the tps Adjusted it will make some difference