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AFR's way too rich, 10.0:1 and richer. Need help!


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So a few days ago I installed an Autometer electric fuel pressure gauge to check to make sure I had adequate fuel pressure cause I was running lean up top and had a random stalling where the Wideband showed I was dead lean, no fuel. Pressure wasnt the issue.

 

The day after I installed the gauge the car started idling at 12:1 AFR or richer. Normal was 14.7 +/- .2 or so. This started suddenly not gradually.

It just got worse from there, part throttle and cruise AFR were 10.2:1 or lower and the wideband I have only reads richest 10.0:1 so I could be even richer than displayed. Decel it would run a little leaner, boosting down low was still in the 10's and up higher I would run in the 12's or leaner so Id have to back off. Once this starts, which isnt long after I start driving, it even idles at 10.x:1 AFR. Ive gotten into boost and its cut out on me from being so rich I get a quick cloud of fuel smoke I can see in the car behind me's headlamps. Other times it doesnt do that but say 3rd gear for sure it will.

 

Ive done the TPS/Idle adjustment 2 times, once a month ago and another time this morning 10am.

3pm today the filters, flushing and new injectors were done.

 

As suggested by others on here I have replaced my fuel filters, all of them, flushed the lines, checked for leaks at the throttle body, intake manifold, and vacuum sources. I even ordered a new set of Delphi injectors. None of which has cured this problem or my running lean up top above 4500. Fuel pressure is 36-37psi idle and cruise, under boost I get the correct rise with boost, after I let off it returns to 36-37psi quickly. Stock injectors didnt leak, these dont either, and the fuel pressure takes many hours to lower below 30psi after shut down. Im currently getting around 7-12 MPG. New OEM oxygen sensor installed last month. New plugs, wires, cap and rotor, timing is dead on and the vac advance is working fine. FPR is also working and tested fine.

 

Tonight I had an idea to baby the car home and NOT hit any boost at all. Car never ran rich, on accel it was 12.x:1 or leaner and cruising it ran near the target 14.7:1 AFR. 15 miles later I decided to get on it and as soon as I let off it ran at 10.0:1 non stop unless I went back into boost or full decel. Now I thought maybe my BOV was leaking or had a bad diaphragm, and by not going into boost I thought I had nailed it. I could go into boost and quickly let off a few times and it would stop running rich. SO.....I took the BOV off, checked for a leaking diaphragm and it held vac. I then decided to take it apart and it was confirmed A OK.

 

Im not sure where else to go on this, 1st gen MAF bad? I unplug it and the car automatically runs like s*** and rich at idle. Plug it back in and it runs like it does initially before hitting any boost. Bad ECM? Dunno there, but I can try another one tomorrow.

 

Im running a boost controller, so no solenoid, and all the connection at the WGA are correct according to the page I read on here. Dont know if I should be getting a code or not. I also dont know if by running a 1st Gen DSM MAF if I would get a code just from the mod if a code exists. Ill have to look into the codes section. I cant find info on how to check a Gen 1 MAF to see if its good cause its a Karman freq unit and everywhere I see they say just swap with another MAF cause diag one is near impossible without the proper instruments.

 

So to wrap it up, Pig rich everywhere but above 4500 RPM's where I run excessively lean on a 16G.

 

Any info I left out feel free to ask, Im about to burn this car. In 400 miles Ive gone through 40 gallons of fuel and probably need an oil change now from contamination. Plugs are oddly still not fouled. I will probably try and video whats going on since that may give a better idea on how the car behaves.

 

Thanks,

Chris.

Edited by Dodge2004srt4
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First things first is put the car back to stock when diagnosing problems likes this, so stock maf, stock piping, no bov etc. Go to the link below and on the emissions section is the vacuum line diagram, make sure they are right. Next would be to do a boost leak test. Report back when you do these things, there is not going to be any magic trick to getting the car running right and throwing parts it is not going to do nothing but cost you money.

 

http://www.starquestgarage.com/manuals/service/conquest/1988/88_conquest_service_nav.html

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Another thing to check would be the coolant temp sensor (look up how to test it dont just buy a new one) Also did you cut the stock maf plug off when you swapped to the 1g maf, if so you could have swapped the two similar green/red wires around and that makes the car run weird as well.
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Another thing to check would be the coolant temp sensor (look up how to test it dont just buy a new one) Also did you cut the stock maf plug off when you swapped to the 1g maf, if so you could have swapped the two similar green/red wires around and that makes the car run weird as well.

The MAF mod was done before I got the car, and this happened suddenly last week. Ive double checked the wiring on that last month via the how to pin by pin. I could swap those two wires around since they are the only ones I cant tell that were done right or wrong. I cant put the car back to stock since I never modded anything on it, so I dont have all the countless parts it would take to start over. The car ran fine before now and now it doesnt. Something on there now must be bad. Ill check the coolant temp sensor, I assume you mean the one that the ECM reads, not the AC or gauge ones? Also any idea if those MAF wires were wired wrong why it suddenly affects the car months later?....Just putting logic to the question asked.

 

The car ran a 13.6 @ 100 by the previous owner, I have the slips.....so it is definitely something gone wrong now, not when the car was modded.

 

Thanks

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it sounds like a vaccum/ air leak to me, but it might also be a leaky injector

No vacuum leaks, checked that....if it were a leaky injector then the stock one I had and the brand new Delphi are both bad/leaking. I dont think lower shores would like me to send it back just to say it doesnt leak. Not much chance in a brand new one that was tested before he shipped it leaking. I am however going to do a leak down test on the plumbing. Just to ease my mind on un-metered air causing the issue.

 

Chris.

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Think about the one thing I tried tonight.....If I dont go into boost the car runs normally, when I run boost the AFR stay rich. I think that is probably the most important diag done thus far to narrow something down. No boost=lots or little vacuum.....no problems, no vacuum leak. Boost is throwing something amiss.
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No vacuum leaks, checked that....if it were a leaky injector then the stock one I had and the brand new Delphi are both bad/leaking. I dont think lower shores would like me to send it back just to say it doesnt leak. Not much chance in a brand new one that was tested before he shipped it leaking. I am however going to do a leak down test on the plumbing. Just to ease my mind on un-metered air causing the issue.

 

Chris.

would sound more like a boost leak since it does it while boosting. or your secondary isn't acting right. Have you tried the sweep test on the TPS to make sure the voltage reads right through the sweep?

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Think about the one thing I tried tonight.....If I dont go into boost the car runs normally, when I run boost the AFR stay rich. I think that is probably the most important diag done thus far to narrow something down. No boost=lots or little vacuum.....no problems, no vacuum leak. Boost is throwing something amiss.

I was thinking about that, would be odd, but does the boost pressure sensor do anything with fuel?

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I was thinking about that, would be odd, but does the boost pressure sensor do anything with fuel?

Yes I swept the TPS last month. I can do it again for s**** and giggles tomorrow. There are no throttle related issues like a bad TPS generally has though. Its smooth as silk, no bucking or stuttering.

Dont have the boost solenoid since it was removed for the manual boost controller.

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Yes I swept the TPS last month. I can do it again for s**** and giggles tomorrow. There are no throttle related issues like a bad TPS generally has though. Its smooth as silk, no bucking or stuttering.

Dont have the boost solenoid since it was removed for the manual boost controller.

not the wastegate one, the one in the corner by the ABS. it sends a signal showing your in boost so the vacuum pump can kick on.

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How about a bad secondary injector. It starts firing then it sticks open or fires very slowly so it seems to stick open so it would be rich until higher rpms when the mix was so poor from slowly firing and having gaps of no fuel. Do you have one injector that's different to put in place of the secondary you have now to test? Idle, cruise and steady throttle without boost doesn't use the secondary. This seems as much secondary injector related as it does boost related. Or you have a torn intercooler coupler or one that appears tight but at pressure it blows out. Tug on all of them. One time there was a tight clamp and connector but it was only pushed up against the end of the mating tube so at first it all looked fine but as the motor pulled up, this was a DSM, it separated and blew the boost out but it idled fine and would rev up fine not moving.

 

Next thing is I'd unwrap the wiring where someone messed with that MAF connector and look at every connection or if one inside has poked through and it shorting to another.

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Next, take the air filter off the MAF. Did bugs build a nest in the bypass tubes? Does the end of the filter block or come close at all to touching the end of the MAF? You aren't using a cone filter and a stock lid and 1G MAF are you? Some, the K&N with the solid end, filters if you didn't use the raised 1G air can lid, the end of the filter is about 1/4" from the inlet of the MAF and if it gets pushed on a little under boost its warm and gets sucked into the end and blocks the air flow. The boost is gone so the end flexes back and lets air in again. I had that happening on a car that came here but he also had wrong sized injectors that were generics and were sticking too. Messed up ebay car from up north east that later blew up last summer.

 

 

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My first guess is a boost leak in the intercooler pipes or couplers. My second guess is that you switched the injector clips by accident. My third guess is that if you take the fuel pressure gauge out and return it to stock, it will run better, and if you want to moniter fuel pressure, you should find a different place to do that.
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not the wastegate one, the one in the corner by the ABS. it sends a signal showing your in boost so the vacuum pump can kick on.

Passenger side? I dont have ABS, and have never seen it. I am thinking of disabling the line going to cruise, if it works Ill explain why.

 

 

How about a bad secondary injector. It starts firing then it sticks open or fires very slowly so it seems to stick open so it would be rich until higher rpms when the mix was so poor from slowly firing and having gaps of no fuel. Do you have one injector that's different to put in place of the secondary you have now to test? Idle, cruise and steady throttle without boost doesn't use the secondary. This seems as much secondary injector related as it does boost related. Or you have a torn intercooler coupler or one that appears tight but at pressure it blows out. Tug on all of them. One time there was a tight clamp and connector but it was only pushed up against the end of the mating tube so at first it all looked fine but as the motor pulled up, this was a DSM, it separated and blew the boost out but it idled fine and would rev up fine not moving.

 

Next thing is I'd unwrap the wiring where someone messed with that MAF connector and look at every connection or if one inside has poked through and it shorting to another.

The MAF harness is heat shrinked and wrapped well, I have the brand new Delphi's in there from Lower shores performance. Has the same issue with the stockers in place. I do need to check for boost leaks, but Im not to that point where I can yet, need the parts for the tester first.

 

 

Next, take the air filter off the MAF. Did bugs build a nest in the bypass tubes? Does the end of the filter block or come close at all to touching the end of the MAF? You aren't using a cone filter and a stock lid and 1G MAF are you? Some, the K&N with the solid end, filters if you didn't use the raised 1G air can lid, the end of the filter is about 1/4" from the inlet of the MAF and if it gets pushed on a little under boost its warm and gets sucked into the end and blocks the air flow. The boost is gone so the end flexes back and lets air in again. I had that happening on a car that came here but he also had wrong sized injectors that were generics and were sticking too. Messed up ebay car from up north east that later blew up last summer.

Just replaced the K&N with a new one for the 1st Gen Eclipse, no can lid, the old filter was concaved from being sucked on, and now this one isnt. It was just a new filter of the same one. MAF was cleaned myself, no change, and wasnt clogged with anything other than some light carbon. I can double check the clearance today, cause that would sound like a winner in my mind too. I can build a spacer to allow more clearance. Since the old one was getting pulled in on the cap of the cone, it is safe to say the MAF was being restricted up top, and now it could be getting suctioned on.....

 

 

My first guess is a boost leak in the intercooler pipes or couplers. My second guess is that you switched the injector clips by accident. My third guess is that if you take the fuel pressure gauge out and return it to stock, it will run better, and if you want to moniter fuel pressure, you should find a different place to do that.

Clips are on the correct injector, I know I can pull off the primary clip at idle and it dies. Car wont run more than slight throttle with the secondary unplugged without cutting out. Soon as the car has 10 gerbil/power in it, it knows that injector isnt active.

 

Ill update soon, have a few things to try.

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DSM Lid extended way up

http://i5.photobucket.com/albums/y178/thetexan88/Powdercoated%20Mitsu%20Parts/P1010029.jpg

 

 

 

Starion lid is just flat on top

 

http://www.b2600turbo.com/images/154.jpg

Edited by Indiana
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1G MAF in a stock Starion air can lid and the cone K&N there's no room for the air to suck into the MAF end.

 

 

Thats probably it then. Im going outside to check and see if the filter is sucked in at all. Then take it off and do one hard pull so I dont chance sucking in foreign matter.

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plus the 1G MAF is a little longer

There is an inch of clearance. I adjusted the BOV harder and ran it, seemed ok, then I took the filter off and the car ran richer on WOT boost and still didnt go rich at idle, maybe its the BOV being set too soft. I think an inch would be enough clearance for the MAF. I installed some bolts in the 2 holes up top to push the top of the filter away from the MAF and keep it from possibly getting sucked in.

 

I also cleaned all the terminals on all the coolant temp sensors, OHM'd them, and cleaned the connector terminals. All sensors OHM tested fine within manual specs.

 

Gotta go drive somewhere, Ill update if anything has changed.

 

Chris.

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I just thought of something on my drive home, are you running a big secondary with your s16g in a 12a housing with the factory wastegate?

 

This problem sounds too much like Dejavu..

I was running the stock primary and secondary before, now Im running the 650/950cc Delphi combo. Seems a little lean at idle and high end. The wastegate is the 3 port factory with one plugged off, one to my boost controller and the other to atmosphere. I think I need the 750cc primary for the AFR to be correct at idle. Its hovering between 17-19AFR now.

 

Chris.

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I was running the stock primary and secondary before, now Im running the 650/950cc Delphi combo. Seems a little lean at idle and high end. The wastegate is the 3 port factory with one plugged off, one to my boost controller and the other to atmosphere. I think I need the 750cc primary for the AFR to be correct at idle. Its hovering between 17-19AFR now.

 

Chris.

not the wastegate actuator.. the wastegate. ARE YOU using the 12A HOUSING? Someone had a problem with boost creep on a s16g not too long ago. the s16g pushes too much air at top end for the stock wastegate to handle.

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not the wastegate actuator.. the wastegate. ARE YOU using the 12A HOUSING? Someone had a problem with boost creep on a s16g not too long ago. the s16g pushes too much air at top end for the stock wastegate to handle.

Dont know, I see it has a 2-3 bolt area that is blocked off on it on the back next to the 3in downpipe. The DP is 3 bolt.

The 12A part is ground off and someone wel known on the forums did the conversion, though I cant remember the name of the shop or vendor. Im not sure what the exhaust housing is from but the manifold is stress relieved and maybe ported??? Beyond that it was done before me getting it. I can look and tell you if I know how to tell the difference between what stock is and what I should have.

 

Chris.

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