wes200x Posted July 20, 2005 Share Posted July 20, 2005 I have an 1985 gl wagon that I put a 1987 gl-10 turbo motor in. I swapped everything out of the 87 dash cluster wiring harnesses everything. The only difference is that the 87 was an automatic and my car is a stick. I got the thing running pretty good but it runs super rich at idle and has a unsteady idle after beeing revved up. It blows raw fuel out when you fire it up in the morning. I have checked all the sensors on the motor CTS MAF coil Idle switch TPS Auxilary idle control valve Egr both purge control valves. It has a new PCV valve cap rotor wires plugs fuel filter and I installed a fuel pressure gauge and it seems to be fine two. So I started going through the wireing since the doner had power windos door locks and the automatic trans their are some plugs that I could not hook up. After going through this I found the F3 plug which says it goes to the knock control unit was not attached. It says it is suposed to be under the right hand dash. My car looks to have the trip computer control unit where the knock control should be. But I can not find this in the engine wireing diagram. It shows that the knock sensor goes straight to the ecm and it does not show the knock control at all. Did the 1987 mpfi turbo use the control unit. If so does anyone have a pic of what one looks like. Maybe I have it in parts box somewhere. Also is the auto ecm different that the manual. I just want to figure out why it dumps so much fuel out at idle thanks for any help wes Link to comment Share on other sites More sharing options...
Ross Posted July 21, 2005 Share Posted July 21, 2005 The '87 probably does not have a knock control unit, it uses a different sensor (single wire) connected directly to the ecu. i say probably, because i think some 87s still had the flapper air flow sensor, in which case it will have a knock control unit. More likely, it has a hot wire air flow sensor, so it wont have a knock control unit. Link to comment Share on other sites More sharing options...
Ozsubie Posted July 21, 2005 Share Posted July 21, 2005 The knock control unit (as found on the flapper type EFI systems) probably wouldn't cause the rich air/fuel mix even if it wasn't installed. It's only function is to retard the timing if it detects detonation, it doesn't have any control over the air/fuel ratio. I had rich running on my EA82T (flapper type AFM) caused by a half dead oxy sensor in the exhaust. Note that I said half dead because it wasn't dead enough to throw a fault code, but it was dead enough to be giving a low voltage output which the ECU interprets as lean and then throws more fuel in to try and correct the apparently lean mix. Other than that I'd be checking things like the engine temperature sensor is within specification. Link to comment Share on other sites More sharing options...
Ross Posted July 21, 2005 Share Posted July 21, 2005 Im not sure if the later ecu will enrichen the mixture when knocking either? I doubt it would be that much if it did. You sure the "Raw fuel" isnt water? Link to comment Share on other sites More sharing options...
wes200x Posted July 21, 2005 Author Share Posted July 21, 2005 Thanks for the answers. I have the hot wire maf so it looks like I don't enen have the knock control unit. Here is the deal with the rich condition. It is only at idle and when it is cold. It seems to run siper rich when the thermo sensor would not even be up to temp for the computer to read it. However I pulled it out and put it in a pot of water over the stove. I took the proper measurements at the proper temp and it reads perfect. It has a brand new o2 sensor also. Is there any way to lean out the whole system. Because doen't the computer run of a pre determined map when it is cold. Link to comment Share on other sites More sharing options...
NorthWet Posted July 21, 2005 Share Posted July 21, 2005 Do the MAF, ECU, engine harness, and chassis harness between ECU and engine harness all come from the same source??? As I understand it, the coolant thermosensor is always "up to temperature" for the ECU's purposes. Also, the problem with the CTS is not usually a bad CTS but bad/unreliable connections to it. Oh, and from what I have read/heard, the knock control module/system does not due anything other than retard the ignition timing. Link to comment Share on other sites More sharing options...
wes200x Posted July 22, 2005 Author Share Posted July 22, 2005 Thanks for the feedback everything engine and electrical is all from the 87. My car was carbureted before putting the turbo motor in. As for the cts when I put it back in the car after checking it , I took a reading at the sensor and then looked at the wireing diagram and it is #9 wire goin into the computer so I unpluged it and it had the same reading at the ecm. Maybe the computers bad. Link to comment Share on other sites More sharing options...
Ross Posted July 22, 2005 Share Posted July 22, 2005 Are you using a completely stock wiring loom? Link to comment Share on other sites More sharing options...
wes200x Posted July 22, 2005 Author Share Posted July 22, 2005 yes it is a completely stock wireing loom. The only difference is that the car it came out of was an automatic and mine is a stick. So there was some stuff from the automatic trans that I could not hook up Link to comment Share on other sites More sharing options...
Ross Posted July 23, 2005 Share Posted July 23, 2005 Have you checked for error codes? How do you know its running rich? The auto ecu with a manual isnt a problem. Link to comment Share on other sites More sharing options...
Cougar Posted July 23, 2005 Share Posted July 23, 2005 I would check the continuity of the wire from the ECU to the CTS sensor. It sounds like the wire is either broken or not going to the correct pin on the ECU. Be sure disconnect the connector from the ECU, with the engine off, before taking the measurement. The fuel problem may also be due to a leaky injector. Link to comment Share on other sites More sharing options...
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