They don't, based on my findings.
Afm, iat, boost sensor, cas are the only ones really needed. Then outputs to injectors and coils. That's it.
Coolant temp sensor, tps, all emissions stuff are not needed.
Tps is a modifier that kinda affects when you are off throttle or partial throttle. Many people have rum without them. When bad, it can eff things up, but unplugged the edu just goes off afm, iat, and boost sensor (map sensor).
All of those sensors above have been rewired with individual wires outside of the normal harness straight to the ecu. The ecu passes each test of what the inputs and outputs should be.
If there is a vacuum leak, I can't find it. Every piece of the manifold has been removed, inspected, and put back on with good gaskets....
At this point, I am worried that the cam has slipped a couple of teeth or the head gasket is going bad...
get 2 cans of starter fluid and go to town. I find often that its the LIM to UIM gasket, or flange to block or any injector bleed because those o-rings rot out and get solid as a rock.
I also have found that when I machined my gasket surfaces for the intake manifold that it would leak no matter what new gasket I put on it, so I used some gasket sealer from permatex to help and that has done the trick.
Yep, checked all gaskets and removed the upper and lower intake manifolds. All new seals on the injectors too.
goop it
FYI, the Miata TPS for the early cars (1990-93) is basically just two switches. One is closed throttle, one is WOT. THe latter turns off the AC, that's it. The former is obviously used for idle calculations, and the car will act differently if it thinks it's at idle or not.
In reply to Keith Tanner :
TPS on an '84-88 RX-7 (may have changed for '89) is a potentiometer, with two weird things about it.
It is a plunger that compresses on closed throttle.
It only functions up to about 1/3-1/2 throttle, after that the TPS is wide open.
Works just fine (don't need acceleration enrichment past tip-in) but the way they always fail is they stick. Then extend well after the throttle is open.
What is the resistance of the resistor block?
I know it's not really that helpful but I am surprised coolant temp isn't a larger factor. Most EFI systems im familiar with drive a lot from coolant temp.
+1 on its probably cam timing.
Although, I just had a thought. I know many ECUs have a calculation table that looks at system voltage and adjusts injector open time based on the voltage, since injectors open more quickly and more slowly with higher and lower voltage. Does the 12V in to the ECU equal the battery voltage? Does it equal the voltage you see at the injectors?
In reply to Robbie :
no camshafts only a crank angle sensor since it is mechanically timed.
Knurled. said:In reply to Keith Tanner :
TPS on an '84-88 RX-7 (may have changed for '89) is a potentiometer, with two weird things about it.
It is a plunger that compresses on closed throttle.
It only functions up to about 1/3-1/2 throttle, after that the TPS is wide open.
Works just fine (don't need acceleration enrichment past tip-in) but the way they always fail is they stick. Then extend well after the throttle is open.
the S5 has the same S4 TPS its just mounted upside down and is on the narrow band only. It also has a wideband TPS that is specific to the s5, the 89-91 use both whereas the s4 only uses the narrow one.
Sorry for bringing this post back from the dead, but I have this same problem and I've been trying to figure it out for years.
Any chance anyone knows what happened? if OP was able to resolve his issue?
everything described is almost exactly my problem. fuel pump rewired, car won't idle unless AFM held open, will start for a bit seem to lean out and die. rebuilt injectors, verified voltages on everything. new AFM new ECU, new vacuum hoses, new gaskets with RTV. Car was running and ideling fine, then it stopped holding idle unless my foot was on the gas just a little, then I parked it and got the injectors rebuilt and it never wanted to run again.
anyways sorry again for bringing up an old post, don't know if I'll get ripped apart for it as you do on some other places, but this seems to be the EXACT problem I have with my car and its been years without any luck on this.
Necrodead said:Sorry for bringing this post back from the dead, but I have this same problem and I've been trying to figure it out for years.
Any chance anyone knows what happened? if OP was able to resolve his issue?
everything described is almost exactly my problem. fuel pump rewired, car won't idle unless AFM held open, will start for a bit seem to lean out and die. rebuilt injectors, verified voltages on everything. new AFM new ECU, new vacuum hoses, new gaskets with RTV. Car was running and ideling fine, then it stopped holding idle unless my foot was on the gas just a little, then I parked it and got the injectors rebuilt and it never wanted to run again.
anyways sorry again for bringing up an old post, don't know if I'll get ripped apart for it as you do on some other places, but this seems to be the EXACT problem I have with my car and its been years without any luck on this.
Unfortunately, no. I believe the engine and car are sitting right were they were 5 years ago...
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