Hmm, down to 10.5:1.....

 

Just open LH box and it seems to have original EPROM in it. No monkey business from PO seen there.

John instructed me how to detach WOT activation signal from LH. Signal is first coming to LH and passed from LH connector to EFZ, in theory it is possible that LH would see WOT and give engine more fuel but signal to EFZ is missing (loose connector, problems in harness etc). Could this create situation where WOT is not significantly giving more power but only way too rich mixture (and some power due increased fuelling)?

Meaning that spark advance of EFZ WOT is not activated, only fuel map WOT.

 

This seems like an unlikely scenario.... which you can quickly verify with a multimeter.

 

What are the last three digits on the EPROM? Should be x527 for 16V. (x590, x631, x721 for 32V)


There are two FPRs on 16Vs. Have the return hoses been changed? It is easy to kink them, which would drive up the pressure. 2.0 bar would show at idle. The spec is 2.5 bar, engine off, fuel pump relay jumpered.

 

They are 515. This is an '84 Euro, 928 618123 00. Different to the 85/86.

 

To be sure, did you measure the Temp II from each pin to the block? Try measuring at each ECU connector. (16V LH/EZF pinouts)



John - Is the 515 soldered on? IIRC, you said the '84 board also has different timing?

 

Tested it allready, there is a continuity between 12 and 17 pins on LH and EZF connectors with marginal resistance.

I'm just shooting into dark, if signal between connectors is intermittent for some reason, could it explain power and mixture problems? In theory?

Ken - precisely same reading @ full running temperature from both tempII pins. I forget to check them again from connectors when drove back to garage. I'll check them to make sure that anyone has not put resistor between sensor and connector...

IIRC 2.5 bar +/- 0.2 bar

Mine is showing 2.3 which is within specs and at least do not explain overfuelling at WOT. If it wuold be 2.8 bar problem could be FPR.

 

The ± of spec is temperature dependent. Cold, the pressure goes up (+0.2 bar/3 psi). Very hot, the pressure goes down (-0.2/3).

 

Ken, you have play a lot on dyno with timing&fuelling. If ignition would not use WOT advance on full throttle, but LH would - what would happen?

 

With a stock chip, if the EZF WOT input were disconnected, then it might make more power. You may feel that the 'flat' feeling when you push the pedal down at lower rpms is lessened.


Before I made chips, I disconnected the EZF WOT. The EZF WOT map is flat, using RPM only. Disconnecting the WOT lets the EZF use the cruise map which is RPM x load (vacuum).


It is a sure sign of winter that I started going through the x527 16V chip last night. (It is similar to the 32V code, just rearranged somewhat, but I think it is much different than the x515, and AFAIK, the '84 LH is different than the '85-'86, unfortunately.) On my S3/32V chips, I make the WOT mixture adjustable by putting a variable resistor on the WOT input to the LH, and new programming to interpret it. (On the 928, the LH WOT input is just a switch, but the LH can accept a variable TPS.)

 

Hi ken, the temp 2 has been carefully measured and is in spec. If anything slightly on the "weak" size of tolerance.

The 515 is in a socket, only the early EZ-F has soldered in EPROMs.

The 00 LH has a clock xtal at half the freq of the 85/86 units. The software structure is quite different to the 85/86 which is why we didn't develop a Sharktuner for the 84.