danglerb

Have the injectors ever been cleaned? Cleaning and replacing the seals remove a lot of variables.

Injector flow depends on the pressure differential between fuel and manifold pressure, sounds like both are not close to stock on your car.

As long as any fuel is being returned to the tank the pump and filter are working "well enough" not to cause problems, and then the problems would start strictly with high load situations.

Maybe check some basic's, throttle position sensor working correctly, vacuum lines routed correctly with no leaks.

John Speake

If you check the circuits, you'll see that 12v to MAF and injectors is via the LH relay. The LH relay is activated by the LH ECU when ignition is switched on.

Did the car have problems before you swapped MAF and ECUs ?

Euro's have a reputation for running weak, but 99% of the time that is because they have out of spec MAFs, or the injectors need cleaning. The 16v Euros are more sensitive to MAF ageing than S4 and later, this makes them less tolerant of deterioration of MAF calibration or injector flow than the later cars. I correct this over sensitivity with my 16v performance EPR|OM sets.

I very much doubt the ECUs have failed, they are very reliable.

85euro928

Dan,
I cleaned the injectors and replaced the seals about two years ago. Granted I cleaned them using a home-made rig as I was just trying to get the car put back together after my cracked camshaft incident but the car ran well before so I'm not sure if the injectors would cause the problem I'm seeing? Also vacuum lines are new as are the majority of hoses on the car. Fuel pressure is about 2psi more than what's called for so that's within spec, the problem seems to be that the vacuum is low.

85euro928

John,
- I jumped 30 and 87 on relay XVI (which I believe controls the ECU) but did not turn the key on but from what I read that's not required? I will go back and do it again turning the key on.
- No the car ran fine with the old MAF and ECU's, and when I changed out to the new ECU's to run your EPROMs the car also ran fine, in fact it ran great (very smooth!). The only reason I had the MAF rebuilt was that I had to se the MAF pot to around 900 ohms to keep the idle AFR below 15.

85euro928

So I ran two separate smoke tests on the intake, one last night and one this morning. I ran them both for about 30 minutes each time, nothing
What else would cause low vacuum? I'm going to borrow a better vacuum gauge today, maybe it's my cheap gauge and not the intake.

85euro928

John,
I just checked the voltage at the MAF connector again and I am get battery voltage across pins 2 and 4 (my mistake I forgot to take in to account that the plug and pins are mirror images). However, I am not getting any voltage at pin 7 of the LH connector. From what I read this indicates a MAF failure? I'm going to borrow a MAF later today from a friend and see where that gets me.

85euro928

Here's a link to the car running. I think the AFR is high because the car was cold. Notice what happens when I rev the engine to 2k RPMs. Is this the unit going into limp-home mode? Do the '85's even have limp home mode?

928wolf

Not to highjack this thread but, how do you check if your MAF is out of spec, and how do you get it back in spec?

Again, sorry for the tangent - I think I'm trying to solve a different problem (poor performance and power).

John, I eventually plan on getting one of your EPROM sets but one the stipulations on your website said you must have a properly running engine first, which I don't think I do right now.

PorKen

Have you 'sanity checked' the position of the cam gear notches?

Are you sure you have a (black label) 16V LH, not a 32V one?


'84-'86 LH2.2 has a limp home mode if the MAF voltage is way out of spec, only.

16Vs only, pin 19 of the LH plug will go to ground for an unimplemented Check Engine Light in this mode.

85euro928

Wolf,
Have you set the MAF pot using a CO tester or Innovate type system? If you have and the MAF pot is over something like 700 ohms then you know the MAF is on it's way out. Other than bench testing I think this is all you can do regarding whether it's in spec or not. There are several other resistance and voltage test you can do with a VOM if your inclined. Check out Johns website, the link is in his sig.

85euro928

I haven't had the car running long enough to sit in the drivers seat and check to see if the CEL has come on. I will go check that now. BTW, those pin out have been invaluable, thank you!

PorKen

You may have difficulty seeing the CEL.
(There isn't one in the pod [until '89] - the LH doesn't know that, though.)


If you have a 32V LH, then you won't have that output. The 32V LH 'octane loop' uses pin 19.
(On the LH it's actually a coding input to use a slightly different O2 sensor map.)

85euro928

Missed the "unimplemented" part...

PorKen

You may have a broken wire at the MAF plug (inside the rubber boot)?



I might be a little more help, soon - going to look at a '85 ROW 5-speed.

85euro928

I pulled the boot off and the wires "look" brand new. I know 2 and 4 are OK because I read 12V at the connector. I need to look through the wiring diagrams to see if I can trace down the other 4.