Another brainstorming session here fella's. Forum member Brian(briza) has a TT AT that he's just put a good 2nd hand motor into. The motor was bought from a wrecker and he saw it running in the halfcut before purchase. It cranks over and keeps kicking but just wont run, Its got spark, that has been confirmed, fuel pressure is at 55psi during cranking , injectors are clicking but the catch is that is is extremely rich and so wont run. Conzult shows CTS at 24deg, seemed about right. throttle pos. 4.48 timing 16 deg rpm signal seemed ok. Injector pulse was jumping around between 5 and 8ms We tried unplugging the AFM, CTS,all other non essentiall sensors and makes no difference removed throttle body pipes to eliminate air restriction. Any suggestions of very rich running would be appreciated!
Mine did something similar, it was caused by the CTS reasing minus 42 degrees so that was my first idea but you have eliminated that one. Is 55psi high for fuel pressure? I thought it was meant to be as 42psi? Other than that, bad injector O rings or the injectors themselves leaking?
ECU? Did the old engine have larger injectors hence the ECU was modded to suit and engine from the wrecker has stock injectors hence too much fuel is getting into the chamber? Are the injectors seated correctly in the fuel rails and are the fuel rails seated properly in the upper plenum?
the only reason im eliminating the injectors and o rings is that it was running fine in the half cut. All the sensors are the same that it ran with, teh only thing different is loom and ecu. fuel fressure did seem a bit high but 55 is not going to make it that rich i wouldnt think
Is the EFI loom plug firmly seated in the ECU socket at both ends? Injector plugs on the correct cyls?
i can rock round if u need to use a tt auto ecu to test it. got nothing on tomorrow. providing it's not a major job to pull it and replace it.
Read this in the Conzult manual once. Do you have Conzult? The Start Signal goes to pin 43 on the ECU, and it is the full +12V. It would be reasonably simple to use a multimeter on pin 43 to check to see that the pin goes high when you turn the ingnition switch to the Start position. Then you will need to make sure the pin is properly seated.
Richness described would indicate ECU is providing choke via start signal. Hence my suggestion that cyls 1 & 2 are not getting spark (ECU plug) or other cyls getting injector firing signal out of sequence through loom connectors being arse-about. Z32 will produce symptoms as described if only firing on 3 or 4 cyls.
yeah thats the most likely thing, i didnt look into it since the motor was running fine just a few weeks ago. i guess its possible it fell over since then
