ZachCRF450

I have a 1991 Toyota Pickup 3.0 that I did a 3.4 swap on about 2 years ago with a 2003 tacoma. The truck ran fine untill a couple of days ago. It would stall out intermittantly then come back on. The Tach would drop to zero than work when the truck would come alive again. It ran fine besides it stalling out but then it wouldnt start later that day. It would just crank and not start up. But then it decided to start? I pulled the codes and it said Cam position Sensor which I changed out today but that did not help, still wont start at all now, Just cranks over.

I dont know much about how the computer works just the mechanical part of the engine. Now when I try to pull a code the OBDii scanner gives me an ERROR code like as if the brain is not sending a signal to the scanner. I have checked all visible grounds and connections. Not sure whare to go from here.

I used the ORS harness conversion so I dont know about the wiring or ECU. How do I check for ECU power or ground problems? Could this be an ignition problem? I posted this on the 3.4 swap forum but no help there. Any suggestions???

stockwell45

iTrader: (1)

to me it sounds like a fuel problem, like sometimes its getting fuel and sometimes its not. maybe fuel pump is going bad

ZachCRF450

Well I found that when I would jiggle the ECU wires that ORS made for the swap I can sometimes get the OBDii to start to scan then the truck will start but then short out and die. If anyone is familar with the ORS ECU harness could they tell me what the blue wire does that is In the middle of two grey wires on a ECM connector that plugs into the ECM. Kinda vague but it is the only Blue wire on that ORS plug. I think it may be frayed and I cant get the prong to come out of the connector that the Blue wire is crimped to. I believe its E5-8

ZachCRF450

Which wire gives the moter a go ahead to start and run and a signal to the OBDii? I found that when the scanner gives an ERROR code the moter wont run but after I wiggle around the ORS harness @ the ECU , the scanner will read then I can start the truck and it runs fine. No codes pulled from the ECU tho. Is this an intermittant ECU that is going bad or a harness short or gound problem? Right now it is running and I cant get it to stall??????? I would hate to buy an ECU then have it stall out again. Whitch wires should I trace to track down this issue?

Beto

Not sure about E5-8 - which model/year is the ECU from? The '03 Tacoma? That wire might have something to do with it, but it sounds like a bad ground to me. Maybe that wire is a ground wire to the ECU. If you can get the wiring diagram from the FSM for that ECU, post the pin number and the description or tag that they give in the manual.

Also, an easy thing to do would be to check the engine ground (on driver's side on/near the intake manifold, at the underhood diagnostics plug). My truck did the same sort of thing when I forgot to tighten that ground securely after putting on a supercharger.

ZachCRF450

IS that the ground on the plentum? Its good n tight. The blue E5-8 is actuallly a wire that ORS had me put directly to the battery adn I got it back in the connector. Now the truck is running fine but I dont think it was that wire? I need to know what grounds the ECU and what powers it up?

Beto

Yes I was thinking the ground on the plenum. I looked at my FSM for 2002 4runner and they don't even have an E5 connector on those ECU's. I'm out of ideas to help you except for suggesting that you get the factory manual for the model/year of the ECU that you are running. It will have the ground points and different power points indicated.

If you can't make it stall out now, it's going to be pretty hard to figure out when/if you've found the problem.

The blue wire that you are describing doesn't sound very good - it's kind of pushed into the connector? You think you've got it back in? Kind of frayed? Is there another wire with that one in the same hole? Could you just splice to that? Before considering a new ECU I'd definitely do whatever it took to be absolutely confident in that connection - including finding out what it supplies power to.

ZachCRF450

Well fitting the ECU in the Truck was pretty hard to find a spot for it to mount. I think I had the wires to tight to the firewall and they could have been putting stress on the ECU pins? I have remounted the ECU where the wires are not stressed at all and I suppose I will try that. It is running good but who knows if I have fixed the intermittant problem. Has anyone had a problem with the pins not getting a very good contact with the wires?