She's Running but AFR climbs to 16:1
#1
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She's Running but AFR climbs to 16:1
I just got her running again (new setup, 87 cam instead of a supercharger cam profile). All is well but the AFRs climb to a steady 16:1. No "check engine" light comes on. Is this normal for '85s? This was happening with my previous setup. Everything is new...injectors, MAF, ECM, O2 sensor. There appear to be NO leaks. Exhaust is TIGHT between cylinder head and O2 sensor. Help!
#2
Melting Slicks
im sure its the tune , my brothers car had the same problem but it turned out to be bad wiring harness , we had to rewire the whole car . check the volts on each injectors and the mass air. if everything checks ok then you just need a tune . it could also be fuel filter
#3
Melting Slicks
GRX,
I agree with Red...
Mine at idle after first starting will go to about 12 as it warms up with the A.I.R. pump running will go to about 15.6 then back to 14.7 ish...
I would adjust up your power enrichment... at cruise with your supercharger you should be around 14.4 "ish"...
I'd check your fuel pressure... what are your injector pulse widths at , at idle... ? you should be around 1.8 ms ~ maybe a little less~
What are your gm/sec on the maf at idle?
If you have a adjustable fuel regulator I'd push your fuel up a touch... What injector size are you running?
Feel free to email or pm me if you want to take this offline...
Mo
I agree with Red...
Mine at idle after first starting will go to about 12 as it warms up with the A.I.R. pump running will go to about 15.6 then back to 14.7 ish...
I would adjust up your power enrichment... at cruise with your supercharger you should be around 14.4 "ish"...
I'd check your fuel pressure... what are your injector pulse widths at , at idle... ? you should be around 1.8 ms ~ maybe a little less~
What are your gm/sec on the maf at idle?
If you have a adjustable fuel regulator I'd push your fuel up a touch... What injector size are you running?
Feel free to email or pm me if you want to take this offline...
Mo
#5
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Originally Posted by red L98
im sure its the tune , my brothers car had the same problem but it turned out to be bad wiring harness , we had to rewire the whole car . check the volts on each injectors and the mass air. if everything checks ok then you just need a tune . it could also be fuel filter
#6
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Originally Posted by Mo_Bandy
GRX,
I agree with Red...
Mine at idle after first starting will go to about 12 as it warms up with the A.I.R. pump running will go to about 15.6 then back to 14.7 ish...
I would adjust up your power enrichment... at cruise with your supercharger you should be around 14.4 "ish"...
I'd check your fuel pressure... what are your injector pulse widths at , at idle... ? you should be around 1.8 ms ~ maybe a little less~
What are your gm/sec on the maf at idle?
If you have a adjustable fuel regulator I'd push your fuel up a touch... What injector size are you running?
Feel free to email or pm me if you want to take this offline...
Mo
I agree with Red...
Mine at idle after first starting will go to about 12 as it warms up with the A.I.R. pump running will go to about 15.6 then back to 14.7 ish...
I would adjust up your power enrichment... at cruise with your supercharger you should be around 14.4 "ish"...
I'd check your fuel pressure... what are your injector pulse widths at , at idle... ? you should be around 1.8 ms ~ maybe a little less~
What are your gm/sec on the maf at idle?
If you have a adjustable fuel regulator I'd push your fuel up a touch... What injector size are you running?
Feel free to email or pm me if you want to take this offline...
Mo
#7
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Originally Posted by STL94LT1
16:1 in open or closed loop? My car reads really lean in open loop, as long as the air pump is running. The air pump will dillute the a/f ratio.
#10
Melting Slicks
Mine, runs for a few minutes at first cold start , it depends on ambient temp. It will as posted above cause your AFR to go to 16's mine is around 15.8 at idle only with the supercharger.... you need tocheck it at cruise, as also posted above 16 cruising around is too lean in my opinion.... I would say it should be at least in the 14's...
Mo
Mo
#11
Melting Slicks
Originally Posted by GRX
red98 - Shouldn't be an issue. All is stock compatible. Cam is an '87 roller; heads are AFR180; CR is 9.2:1. The MAF should compensate for the minute extra breathing.
if i got this right you had a blower cam and the car was tuned for this cam and all you did was take the blower cam out and go back with a stock cam . right??
if thats what you did what was the spec of the old cam and the new cam ?? it could be the LSA diffrence whats making the car run lean
#13
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Originally Posted by red L98
if i got this right you had a blower cam and the car was tuned for this cam and all you did was take the blower cam out and go back with a stock cam . right??
if thats what you did what was the spec of the old cam and the new cam ?? it could be the LSA diffrence whats making the car run lean
if thats what you did what was the spec of the old cam and the new cam ?? it could be the LSA diffrence whats making the car run lean
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One question, where do you have your wide band o2 sensor placed? If its just stuck in the tail pipe at the rear of the car you maybe getting dilution. The best place for the sensor is in the exhaust pipe just down stream from the collectors. On most of the cars I have tested in this manner with GM controllers and in closed loop, the PCM or ECM will control to 14.7 plus or minus a tenth or two. The AIR pump usually fires up on cold start ups to get the catalyst going once its in closed loop it shouldn't come on.
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Originally Posted by GRX
tjwong - WBO2 sensor is about 4 inches downstream of O2 sensor.
#17
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Ok, I tightened the oil pan bolts. Then cleaned with acetone the bulhead connector contacts (by the battery), and my AFRs bettered to about 15.4:1 !!!!!!!! Any ideas why? All input appreciated.