4agze fuel injector feed question

[draz]

Hey guys and girls,

Ive done an engine transplant in my car and now have a problem with the setup.
Ive got a 4agze from a map sensored '92 Trueno with loom and computer. Been trying to get it tuned so I can pass roadworthy here in SA. Started out ok but the guy put it on the dyno and found it was running lean as, from idle all the way up the rev range. The regulator and fuel pumps are new, filters and fuel lines have been checked and all ok.He was going to get the injectors checked but I went there today and he tells me the injectors are only pulsing at 30%!!! The diagnosis plug isnt working either so Im not sure whats causing the problem and not real sure where to look, Id say it was the computer, but not being a mechanic its only a guess.
Anyone out there had a similar problem? Or if anyone has an idea of what to look at Id be keen to hear any helpful comments from members. Pretty frustrated as its so close to being ready.
Thanks all

[fixeruperer]

thrown a fuel pressure/flow gauge on it ?

id trace back the wiring to make sure it all works with the diagnostic (imo, if youre going to use a stock ecu, it may as well all work). if not, maybe think about getting an aftermarket ecu.

[draz]

yep, pressure and flow is all good...in fact I had to add a reg to cut back the pressure. I have to use the stock ecu for reg purposes, so Im stuck with finding this problem.

[fixeruperer]

faulty map sensor maybe ?

car runs fine, besides being lean ?

[draz]

could be a faulty map...is there a way to check them??

car runs nice and smooth but way down on power

[trdee]

Faulty map ought to come up in a diags check I would have thought. If fuel flow and pressure is ok then it can only really be an issue like that though. Did you wire up the injector ballasts? I don't think they would have that effect though, the car would probably still run the same just the ecu would get bullshit hot and maybe fry...

[draz]

unfortunately the diag plug isnt working, not sure why as the entire loom was checked before installing in the car. If I have to trace all the wires back I think it'll be an engine out job :-(...Ill try and get another map sensor from somewhere...Im not sure what injector ballasts are..

[thechuckster]

what is the fuel pressure with ECU/IGN on but motor not running? Then also measure with motor running at idle. You should get 32-28psi for test #1 and ~20psi for test #2.

As for injectors only pulsing at 30%, that's fairly meaningless information unless you know at what revs and what the manifold vacuum/boost was at.

They (4AGZE) are largish injectors and unless on boost, the duty cycle is going to quite small.

When you say "I had to add a reg to cut back the pressure" - I presume this to mean that you added a factory regulator on the rail where it normally goes? Just checking that you: A - don't have 2 regulators, B - have it at the return end of the rail where fuel is heading back to the tank.

You can access the diag port at the ECU - you just need to know what pin it's on (e.g. find correct wiring diagram for ECU) and then piggy back a wire on the identified pin/wire, also bring out an earth. Shorting your new test wire to the earth wire should put the engine into diag mode (and get any error codes from the check engine light).

[draz]

Thanks for the help and questions so far. I took this info to the mech today and....as for the 30%, that was while running on full boost. Reg was connected to fuel return end, original blanked off or removed (not sure which) but only 1 reg anyway and yes he's aware that he can access the diag wire at ecu but hasnt got to that yet.
Im looking into buying another map to check but thats a bit of a task but if anyone who reads this has one with the number 89420-12050 that you dont want please let me know.
cheers
david

[Omegaman]

Just a guess, but is the TPS adjusted correctly.
i know my car ran fine but no power, till this was adjusted..

[draz]

Hmmmm...good point. I know it was pulled apart but I wonder if the mech has checked......thanks for that Ill ring him.

Just for my info....how do you check if its adjusted correctly?

[Omegaman]

Just google Adjust toyota TPS sensor or similar and you will find heaps of info.
here's one i found earlier.
http://www.4crawler.com/4x4/CheapTri...Adjustmentinfo.

try youtube also.
cheers

[draz]

Thats a great link..phoned the mech today....TPS is set up correctly... 2nd hand ecu arrived today so thats around there for him to try. Only thing left to replace is the map but do far no luck finding one :-(

[PrettyCoolWagon]

interesting post.. got any updates ..did you find out what the problem was??

[draz]

Hi, the new ecu didnt make any difference (there goes $300) I found a map in Kentucky USA..$80.00 delivered, it should arrive this week. Ill let you know what happens there. Im really hoping thats the problem, if not its an expensive sparky job to trace all the wires to see if theres a broken one somewhere.....not to mention an engine out job...pain in the arse :-(...