[88_acro]

so i decide to do the EACV test in the haynse manual again and when the ingnition switch is on there should be no voltage between the black/yellow and blue/red wire BUT i have voltage the book say if you do you have a possibility of a faulty ecu. What should i do replace the ecu or take it to the stealer either way it is gunna cost me lots of money but im might be able to get a deal on an ecu at the junkyard this car is pissing me off im gunna sell it!

 

[KAHruzer]

My OEM manual says there's to be 8-15 Ohms resistance between the 2P connector terminals. If not, replace EACV. If so, check for continuity to body ground on each of the two connectors on the EACV side. If exists, replace EACV. If not, turn ignition ON. Measure voltage between YEL/BLK(+) and BLU/RED(-) terminals. If battery voltage DOES NOT exist, measure voltage between YEL/BLK(+) and body ground. If NO BATTERY VOLTAGE, repair open in YEL/BLK wire between EACV and Main Relay.

The rest of the test centers on the ECU, so see if you get this far.

Disconnect harness from the ECU. then jumper A11 connector to the A18 connector on the harness side (not ECU). Do you hear a click in the EACV? If not, replace EACV.

There should also be battery voltage between A11 and A18 on the connector side of the ECU harness, NOT THROUGH THE ECU. If not, repair open in BLU/RED between ECU (A11) and EACV.

 

[KAHruzer]

IF you have battery voltage between YEL/BLK(+) and BLU/RED(-), it says to disconnect "A" connector from the ECU. Is there still battery voltage? If YES, repair short in BLU/RED wire between the ECU(A11) and EACV. If not, then replace with good ECU and retest.

 

[88_acro]

which service manual do you have all my says if you have voltage to take it to the shop then i goes on to somthing else

 

[KAHruzer]

I have both the '87 and '88 Coupe OEM manuals.

 

[88_acro]

oh sorry oem never mind

 

[88_acro]

i have no clue as to what the a11 and a18 harnesses are i quess ill go to junkyard and get a new ecu

 

[KAHruzer]

The harness connector to the ECU has three sections seperated by the plug. They should be labelled "A", "B" and "C".

The connector (female) and the ECU (male) match pin for pin. The pin layout for the "A"-part of the connector is numbered sequentially as A1 through A18 ( B1-B20 and C1-C16) with odd numbers along the top row and even along the bottom row. (iow, vertical pairs of two pins, odd up, even down).

Your manual surely has a diagram of this connector somewhere.

 

[88_acro]

ok ill check

 

[VegasBud]

is your current mpg working on dash computer?

i had code 14 problem. my speed sensor was not working, i re-solder guage assembly. now dash computer works and idle is fine. the problem before being fixed was, idle would be high(1000-1100rpm). now the correct 600-800rpm. i have '87 coupe ls.

 

[88_acro]

were is the speed sensor? my gauges work fine the speedo needs to be lubed but when not throwing the code and warm it idles at abot 700rpm



anyway i bought another ecu and it show a red led constantly and wont start anyone know what up and the two ecu look diff ill take a pic

 

[KAHruzer]

Apparently, you did not get a matching ECU. They must match your tranny and not be a 1990 version, which is very different. Not sure, but years 1987-89 should work. Not a 1986 version since that preceeds the Coupe.

A constant ON red LED on the ECU means dead ECU. But, in your case, I'd guess it to only be the wrong version. If not a 1990, then it's probably for an automatic transmission version.

 

[KAHruzer]

Which car you're dealing with here. Not sure your '88 Sedan's ECU would work or not in your '87 Coupe, or vice-versa. I think the ECU has also to match the vehicle model, too. And, they locate differently from Coupe to Sedan.

 

[88_acro]

Which car you're dealing with here. Not sure your '88 Sedan's ECU would work or not in your '87 Coupe, or vice-versa. I think the ECU has also to match the vehicle model, too. And, they locate differently from Coupe to Sedan.

well the same day i got the new ecu it didnt work so i decided to take it back but before i did i took the ecu out of my sedan to see if it would work and it did no codes and it felt more responcive (less lag) the only prob is if i got another ecu if it was a sedans it wouldnt mount correctly and its hard to see codes

so today i called the place i got the ecu from and i got them searching the whole bay area for a 87 coupe 5 speed ecu its gunna cost me $100 plus tax but its not as bad as the dealer they want $900

 

[KAHruzer]

$100 ain't bad. But, you could do better if you look around here for folks parting out their cars.

 

[ND1980LS]

Check Ebay also !

 

[88_acro]

i did ebay and craigslist all i could find were autos or sedans or 90's and i feel as though i cant trust people on the net any more (ebay srewed me over as it does to everbody) also i have a guarentee were im buying mine so incase anything goes wrong then i can take it back