Evoz17 Posted September 30, 2014 Report Share Posted September 30, 2014 (edited) Ok I have tried all I know and now its time to ask for some help. My 86 did not have a maf sensor when I picked it up. So I said why not go with the 1g maf. I installed it and it idles full rich.Came across a 1g MAFT, could not get the idle tune, it would either be full lean or full rich.I now have installed a 85 maf and it idles full rich. I picked up a 86 maf but its gutted no honey combs. If I unplug either injector the car dies. This is what I have done, injector clips, cap, rotor, ngk plugs an wires, trilogy fuel pressure regulator, Set mechanical timing and base timing, set tps and reset ics. TB rebuild. Will a bad vacuum advance cause a rich condition? My next thought is bad ecu. I have a SAFC I can try with the stock maf. Some other things ive done are in my restore thread. What else should I check? Edited September 30, 2014 by Evoz17 Link to comment Share on other sites More sharing options...
techboy Posted September 30, 2014 Report Share Posted September 30, 2014 My car was running rich when I first got it as well. Turned out to be the CTS. The ecu uses that and the MAF signal together. Have you replaced the CTS? If not, it's a simple fix and it's cheap. You can grab one on Rock Auto for like 10 bucks. Link to comment Share on other sites More sharing options...
Evoz17 Posted September 30, 2014 Author Report Share Posted September 30, 2014 Wow, I should have thought of that. I will try that next. Link to comment Share on other sites More sharing options...
scott87star Posted September 30, 2014 Report Share Posted September 30, 2014 It's unlikely a bad ECU, more likely dirty injectors that aren't spraying correctly. Link to comment Share on other sites More sharing options...
Evoz17 Posted September 30, 2014 Author Report Share Posted September 30, 2014 I also have a set of trilogy injectors but i could not get them to seal. I ordered a CTS from napa as it will be here tomorrow. Link to comment Share on other sites More sharing options...
ucw458 Posted September 30, 2014 Report Share Posted September 30, 2014 The mass without the honeycomb is junk. Most mitsu mass air sensors are karmen vortex sensors. They read air flow by measuring the vortexes in the incoming air. The honeycomb straightens the airflow and helps produce those vortexes. Without it the mass readings will be off. Link to comment Share on other sites More sharing options...
Tim_C. Posted September 30, 2014 Report Share Posted September 30, 2014 What is the FP at the TB? It can't be much over 45 without it going very rich at idle. Should be 37 - 39PSI or so. The new regulator may be allowing too much FP. Link to comment Share on other sites More sharing options...
Evoz17 Posted September 30, 2014 Author Report Share Posted September 30, 2014 It was pre set to 42psi, I then started to lower it to see if the wideband would read lean. Still read rich at 34 psi. As of now its set at 38 +/- psi. Acoording to my temporary mechanical pressure gauge. Link to comment Share on other sites More sharing options...
Tim_C. Posted October 1, 2014 Report Share Posted October 1, 2014 What you can do is block one of the non-metered port holes in the MAF. Use a stock air filter too. See if that helps it or makes it worse. If it helps (leans it out some), then the MAF signal is not being interpreted correctly somehow. Directly related to MAF signal, but not a bad MAF. You can just run it like that with the port blocked. If it leans it too much, then you can drill a hole in the plug to open it back up some. I have one car that I run like that. Plugging the port smoothed it out and made a huge world of difference to run very smoothly with plenty of power. Any and all MAFs were running rich on it without the port plugged. If it makes it worse and richer, then most likely the real problem is elsewhere, with something telling the computer to spray more injector. You can try putting a stock O2 sensor, or a standard 3-wire one in it too. Just to see what that does. These cars idle rich normally too, so a little rich is okay. Unplugging an injector shouldn't kill it, especially if it idles rich. You'd think the one injector would still keep it up. Link to comment Share on other sites More sharing options...
Evoz17 Posted October 1, 2014 Author Report Share Posted October 1, 2014 (edited) I still have a new one wire O2 sensor in the stock location. Wideband is farther down. The stock air filter is on there but not inside the factory bucket/case. I looked in my 86 manual and theres voltage readings for the CTS and the readings seem are on par. Cold engine is at 3 volts and warm around 160 *f voltage reads at .6 volts. Im going to pick up my new CTS from napa later today. But after trouble shooting last night and noticed my WB started to read full lean i checked the ohms on the injectors and the primary read open no ohms reading. The secondary was at 3 ohms. I threw in the Trilogys but car will only start if i give it gas and keep it alive by reving it. Let go of the gas pedal and it dies. Good thing i found a set of stock injectors last week and they got here a few days back. Ohm's reading on them are 2.8 and 2.9 on them. Both are stamped J. Going to try them later after work. Im assuming the bad injector was just purring fuel and finaly gave out causing the WB to go lean. Update The CTS is not the problem, Both the old and new sensor test good. I put in my spare J injectors with good ohm's reading, car idles full lean now.Im thinking my next step is to send the injectors out for service. Boost leak test. And trying another wideband sensor. Edited October 2, 2014 by Evoz17 Link to comment Share on other sites More sharing options...
techboy Posted October 2, 2014 Report Share Posted October 2, 2014 (edited) Good, you ruled out the CTS. Your info on the injectors doesn't seem right ... somethings fishy. You shouldn't have 2 "J" stamped injectors in there. They are probably the same injector. What color(s) is the top plastic part? I forget what the stampings are on the stock injectors, but I think it's like M and L or something like that. If nobody else posts up w/ the correct stampings I'll check my car. Right now it's outside and it's dark. EDIT: If you take the OVCP off and look in the TB after the car has been off for a while can you see fuel dripping, or sign of fuel leak? Common thing w/ the old injectors on these cars. Edited October 2, 2014 by techboy Link to comment Share on other sites More sharing options...
pcristquester Posted October 2, 2014 Report Share Posted October 2, 2014 Good, you ruled out the CTS. Your info on the injectors doesn't seem right ... somethings fishy. You shouldn't have 2 "J" stamped injectors in there. They are probably the same injector. What color(s) is the top plastic part? I forget what the stampings are on the stock injectors, but I think it's like M and L or something like that. If nobody else posts up w/ the correct stampings I'll check my car. Right now it's outside and it's dark. EDIT: If you take the OVCP off and look in the TB after the car has been off for a while can you see fuel dripping, or sign of fuel leak? Common thing w/ the old injectors on these cars.He's good with injectors. The 86 has two J's, unlike the 87-89's that have an L and an M Link to comment Share on other sites More sharing options...
Evoz17 Posted October 2, 2014 Author Report Share Posted October 2, 2014 I could take off the charge pipe but on my pressure gauge it stays at 38 psi and will stay there for over 15 min for sure. I ran into town for the new CTS, 30 + min round trip and pressure was just below 38 psi. Link to comment Share on other sites More sharing options...
Evoz17 Posted October 3, 2014 Author Report Share Posted October 3, 2014 Ok I went and got a new wideband sensor and placed it in the stock O2 location (for testing purposes). With the new sensor during idle the gauge will sweep from max rich to max lean. After a rev of the engine it will stay on full lean. I will be sending out my stock injectors for service, just cant decide to send them to witchhunters (4 days backed up) Or drive out of town to the nearest injector shop. Link to comment Share on other sites More sharing options...
Evoz17 Posted October 25, 2014 Author Report Share Posted October 25, 2014 Got back my oem injectors from witch hunters. My wideband still sweeps as its a narrow band. Full rich to full lean. After its warmed up it stays on full lean. Now my last thought is that since the engine got rebuilt .20 over, the larger displacement is causing the out of wack air/fuel ratio. Any of you guys with rebuilt engines come across different afr with the oversized pistons? Link to comment Share on other sites More sharing options...
Recommended Posts