76FJ55

I have cleaned the grounds as well as verified the connector at the Temp II. The temp II sensor wire casing had started to deteriorate but the wires them selves where in good shape, so I added a little electrical tape to ensure they didn't bridge, and verified the resistance readings where within spec at the LH and EZF connectors.

Also in logging the the voltage between the pin 25 and chassis ground this should check the integrity of the ground in the V at the back of the engine. I did have small spikes in this reading as illustrated above but they where momentary and quickly returned to ~0V after each spike. Do these skipe indicate that I still have a ground problem or does the overall indication that the Voltage returns to 0 rapidly indicate that the ground is good? I don't know?

jcorenman

This is WAY off, and if correct would be a prime suspect.

The MAF should show about 1.7 to 1.8 volts with ignition on, engine stopped (give or take a tenth or two). With the engine idling you should see about 2.6 volts, as John said. This is critical, if the MAF voltage is more than a volt low then the mixture would be extremely lean (LH thinks there is much less airflow). But that's not consistent with your logged AFR.

You said it ran OK if you swapped the original chip and FPR back in, correct? Same MAF?

And swapping MAF's made no difference?

Which all makes me suspect that the logged MAF voltage is not correct. How are you measuring the MAF volts, exactly? Any voltage divider? Where did you pick off the MAF volts, and which ground point are you using for reference?

PorKen

I looked through the thread and couldn't find any mention of the injectors? Have they been ultrasonically cleaned, or do you have new flowchecked Fords? If they are dirty they may not handle the extra pressure properly?

The chip you have will run richer if you plug the LH 'octane loop' connectors together (don't plug the EZF connectors together). See if this shows on the logging.

76FJ55

Jim,
Earlier during testing I had swapped the original fuel chip and FPR back in to see how it would run, and in doing so it seemed to perform better,but only for a couple of days then it went back to what I believe is the lean condition I still have. Like wise with the MAF swap it seemed to help some but again didn't cure the problem. The testing at that time was all done by back probing the NB O2 with a DVOM. Since installing the new MAF I have not gone back to the original so I have no logged data with the old to compare voltages between the two. I may do so just for reference, though at the moment, I don't think I would learn much from it as i speculate they will read in the same range.

To connect to the signal I made my version of Ken's BRIDGIT, by salvage yarding a harness and computer connector out of a Saab Turbo. I soldered the connectors back to back and then soldered leads to each pin and ran to a 25 pin D-Sub connector. I then crimped the male D-Sub pinsto the leads from the LM-2, so I have a convenient place to tap into any of the LH pins. I then attached the leads from the LM-2 to pins 6 (MAF reference) and pin 7 (MAF signal). This is a direct connection with no voltage dividers, so the LM-2 should see the same voltage for the MAF signal as the LH

Ken,
The injectors are all original, nothing has been done to them. You could be right, about them being the issue, and it is something I have considered. The car sat for about five years before I acquired it, so I know fuel satin the lines for quite some time. When I changed the fuel lines when all this started I noticed the inside of the lines where a bit crusty looking, and thought that I may have knocked some of it loose during the fuel line replacement at that it may have found its way into some of the injectors causing problems. When I switched back to the original FPR and chip and it started running better I assumed the injectors had to be functioning ok, or the performance wouldn't have improved. the performance of course declined again after several days of driving of course, but it was light switch like reactive, it would run well to a point when I turned it off then on the next start up it ran poorly. I would then make some sort of change (clean 14 pin at front right, which turns out to not be even related to engine management) and it came back temporarily. With the way the power would come and go it seemed more electrical than fuel flow at the injectors, but that may have very well been a misconception. I had not considered how the change in fuel pressure may have effected the system. When changing to the higher pressure the performance dropped, then upon changing back to low perf. came back shortly then dropped off then changing back to high saw no net benefit. This kind of makes sense to me know. here is my logic let me know what you think.
when I changed fuel lines I dislodged contaminates from the inside of the lines which caused the injectors to partly clog. This coupled with the short pulse width of the remapped chip would lead to lean running. When I switched back to the original chip the pulse with was greater, and with the lower pressure the flow rate through the injector would be lower leading to less of a pressure drop through the restricted injectors. Then with more operation the injectors became clogged worse causing the decrease in performance. then upon changing back to the new chip and higher fuel pressure no gain was evident.

So as the injectors are now suspect, the question is which way to proceed. Should I send mine out for cleaning or install Ford injectors? I am inclined to install Ford injectors, so if I go that route I see that there are a couple styles of F injectors, notably EV1 and EV6. I assume I need EV1s? are EV1 and EV6 interchangeable? I know I need 24 lb/hr injectors, and the Fords are supposedly a drop-in into the 85. If I go with the Fords should I limit my search to EV1 or are EV6s an option, it seems the EV6s can be found less expensively but I don't know anything about them. guess I'll be doing a little research.

Lizard928

The EV6 uses a different style plug.
You can use them but will need to modify your engine harness.