88 GT hatchback Runs Super Rich.

[Wrenchbender63]

Hi Guys newbee here. I'm going nuts trying to fix my wife's car and was hoping to get some help. I stopped at the store came out and it cranked with no start. I brought it back to the shop , checked the spark and injector pulse. No injector pulse but has spark. injectors had power. I replaced the ECM with a rebuilt Cardone brand and it started right up but runs rich as hell. I will try to not make a long winded story, over 9 months time of working on it when time allowed I have replaced the ignition module, distributor rebuilt, throttle position sensor ,fuel pressure regulator ,ignition coil , dist. cap, ignition wires ,spark plugs ,8 new fuel injectors, map sensor , new oxygen sensors, all new vacuum lines, reman computer, new fuel pump, blew through all fuel lines pressure and return , checked firing order checked TDC and conformed the rotor is phased properly. The timing is set to 10 deg. with spout disconnected. fuel pressure is 35 psi. What am I missing. I have tried 3 different maps 2 different pressure regulators 3 different ignition modules. today I ordered a new ACT sensor and the coolant temp sensor on the heater core pipe. I will install them as soon as I get them. and will post the results. One odd thing is the fuel pump starts as soon as the key is on no short pulse of fuel and then off. runs constantly. There is no check engine light in this car. I picked up a cheap code reader today and will try to pull codes tomorrow. With the exception of the harness there are no more parts that can be defective. I'm suspecting a bad calibration on the computer I bought. If this was OBD2 I could hook it up to the Snap on scanner and get some info. Any help would be great .

 

[broncojunkie]

I see you posted this over a week ago. Sorry I'm late to the party! It does sound to me like a bad ecm. Where do you live? I think I still have the one from my 88. I did the maf conversion on it, so the speed density ecm is still sitting on the shelf. But I would think they would be easy to find and pretty cheap if you want to grab a used one just to check it.

A couple things I would also check would be the throttle body. Make sure there's not something weird going on there, such as a blockage (mice?). After doing that much work, you've probably been through it already. Also, same situation... the air filter and housing.

And one more thing. The thermostat. Is it running cool? Mid? Hot? In my experience, speed density cars will run rich if they're too cool. For example, if you had a failsafe t-stat that is in the "stuck open" position and never reaching full operating temp, it's probably running rich all the time.

Just a few ideas. Check back in and let us one what you come up with!

 

[Wrenchbender63]

Hi Guys newbee here. I'm going nuts trying to fix my wife's car and was hoping to get some help. I stopped at the store came out and it cranked with no start. I brought it back to the shop , checked the spark and injector pulse. No injector pulse but has spark. injectors had power. I replaced the ECM with a rebuilt Cardone brand and it started right up but runs rich as hell. I will try to not make a long winded story, over 9 months time of working on it when time allowed I have replaced the ignition module, distributor rebuilt, throttle position sensor ,fuel pressure regulator ,ignition coil , dist. cap, ignition wires ,spark plugs ,8 new fuel injectors, map sensor , new oxygen sensors, all new vacuum lines, reman computer, new fuel pump, blew through all fuel lines pressure and return , checked firing order checked TDC and conformed the rotor is phased properly. The timing is set to 10 deg. with spout disconnected. fuel pressure is 35 psi. What am I missing. I have tried 3 different maps 2 different pressure regulators 3 different ignition modules. today I ordered a new ACT sensor and the coolant temp sensor on the heater core pipe. I will install them as soon as I get them. and will post the results. One odd thing is the fuel pump starts as soon as the key is on no short pulse of fuel and then off. runs constantly. There is no check engine light in this car. I picked up a cheap code reader today and will try to pull codes tomorrow. With the exception of the harness there are no more parts that can be defective. I'm suspecting a bad calibration on the computer I bought. If this was OBD2 I could hook it up to the Snap on scanner and get some info. Any help would be great .

well I since replaced the air intake temp sensor and temp sensor in the heater core line no change. I then called the company I bought the computer from and talked to the tech dept. they said it was probably the ECM and sent a new one with a different part number and it worked perfect. now I'm reversing all the adjustments I made and giving it a new set of plugs and an oil change today.

 

[broncojunkie]

Glad to hear! Don't you hate going through all that time and money and headache only to find out it was something you already addressed? Seems like it happens way more than it should. I went through it on a tfi module and, believe it or not, an air filter (brand new). I'm fighting a random misfire right now. Air/fuel ratio is spot on. Plugs look perfect. Timing perfect. Plugs, wires, coil all passed ohm tests. It's carbed (holley). Transition slot perfect. No vacuum leaks. Runs like a r@ped ape when you feed it the beans. I'm sure it's something goofy lol

 

[Wrenchbender63]

Glad to hear! Don't you hate going through all that time and money and headache only to find out it was something you already addressed? Seems like it happens way more than it should. I went through it on a tfi module and, believe it or not, an air filter (brand new). I'm fighting a random misfire right now. Air/fuel ratio is spot on. Plugs look perfect. Timing perfect. Plugs, wires, coil all passed ohm tests. It's carbed (holley). Transition slot perfect. No vacuum leaks. Runs like a r@ped ape when you feed it the beans. I'm sure it's something goofy lol

Thanks for the input. I'm trying to get it to behave now . I changed so much that now i set the idle speed upon starting it revs to upper teens for a minute before it settles down to base idle. I'm hoping that driving it for a few days will get things to relearn. For some reason when this happened the a/c compressor started running all the time regardless of the settings in the dash. So today I will try to chase that down.