Target A/F (Speed Pro)

[Jeff Rand]

For some reason my stage 2 is running rich (approx 10.75a/r at idle) I have 83# injectors, fuel pressure is at 34# with vac.line attached, vacuum is 18 inches, timing is 38 degrees (idle), voltage is 13.5 and new plugs (old plugs showed a rich condition along with burning eyes). Checked the coil resistance and the spark plug wires (all were in the 120 ohm range, coil was <11 ohms). With the engine at operating temp. and the FAST (batch unit) in closed loop with the target a/r set at 13.5, I am reading 11.7 and -25% correction. The fuel map numbers that it idles at are at 26- 27 and if I try to lower these, the engine starts "roll" and then dies and the correction still reads -25% with the a/r moving up to 12.3 (stange that the engine does not want to run when lowering these numbers). I will pull the injectors and have them tested next week. Any other suggestions? I think that I have all the enrichments set at zero but if someone has a quick review of the enrichments that I should check, that would be heplful. I had also tried to run in open loop with the same settings and the a/r was 10.78.
Thanks,
Jeff

 

[bobc455]

Does this problem exist under other conditions (mid throttle, WOT)?

What is your timing under this condition? I wonder if you are getting a surge because of too much timing, and you have to make it super-rich to smooth it out.

When you say your "fuel map numbers" are 26-27, do you mean your VE values?

-Bob Cunningham

 

[Jeff Rand]

Thanks for the reply Bob. I have been using this Speed Pro for 1.5 years and before I pulled my stage 1 last year I started seeing this problem. I just got the stage 2 running and I still have the problem. The numbers 26-27 are the VE values at idle. It seems that it is rich at various rpms (the car still needs the trans. to be operating). At 2500 rpm the timing is 40 and the a/r is 10.63 with a target of 12.4 and a corection of -25%. I got a similar result at 2000 and 2800 rpm.
Jeff

 

[norbs]

The ve value is in range, my ve is 29 at idle, 83 injectors. DO you have any exhaust leaks near the o2?

 

[Jeff Rand]

Still working on the problem. I have the injectors out to be checked and I am now looking at the M.A.P. sensor. Should have it running on Wed. Any other ideas?
Jeff

 

[fast4d]

is your alternator putting out the same voltage as before? how about adequate grounding for the alt and engine?

I had my acessories brackets powercoated while I was going turbo from S/C. Since then the car hasn't been running the same. very high VE, inconsistent performance, etc. After some testing with a multimeter I figured my alt wasn't grounding properly. Added a ground strap for it and 1 for the engine and now my voltage is steady and car is running much better. I had to lower my VE about 15% over all too.

 

[Jeff Rand]

Originally posted by fast4d
is your alternator putting out the same voltage as before? how about adequate grounding for the alt and engine?

I had my acessories brackets powercoated while I was going turbo from S/C. Since then the car hasn't been running the same. very high VE, inconsistent performance, etc. After some testing with a multimeter I figured my alt wasn't grounding properly. Added a ground strap for it and 1 for the engine and now my voltage is steady and car is running much better. I had to lower my VE about 15% over all too.

The Speed Pro is showing 13.5v and I have a 200 amp alternator. I also have Casper's volt booster. I have a ground wire to the engine in the front and another one to the coil. I will pull the volt booster out of the system and recheck the grounds and the alt. output.
Thanks,
Jeff

 

[Jeff Rand]

Update - Had the injectors flowed and checked for leakage; all are in excellent shape. Also checked the resistance and they all read between 2.6 to 2.7 ohms. Pulled the MSD out of the system, changed the 3 bar M.A.P. sensor and rechecked all the grounds. Alt. voltage that the Speed Pro sees is 13.7. At idle with the engine warmed up and in closed loop, it is still trying to pull out fuel (-25%). TPS is set at .42 v
Jeff

 

[Jeff Rand]

Update - Found some minor problems but none that seem to relate to the rich condition. Thought the diaphram in the fuel regulator had a leak but it checked out O.K. My referance angle with a BHJ balancer is 10 which seems to be more then most of the posts that I have read on the subject (usually it is 6). Pulled out the volt booster, checked if my second fuel was on at idle and dropped the fuel pressure to 30 psi with the vacuum line on. One thing that I saw last night, is when I put the car in drive the a/r goes from about 11.5 to 13.5 in open loop. The engine also has a problem when it is first started; it dies after a few seconds. also in drive it is not a smooth idle. On the bright side it is a scary ride at 15# of boost with street tires. Tonight I might try to data log a couple of blasts.
Jeff

 

[Ricky Trussell]

Do you have an IAC opening too much when you put it in gear? Maybe that is causing your idle problem too.

 

[S2V6RACER]

The engine starting problems are related to your cranking fuel, after start revs and then the cts enrichment. If you lowered your fuel pressure it may have affected all of these. I know my setup with the 96lb injectors are VERY sensitive to cranking fuel, that has to be right, then the revs are set at around 23 to 20 depending on temperature of the engine. My base pressure is 48psi without the vacuum line. I am at a loss on your problem though. Have you tried anybody elses GCT file? What size motor are you running?

 

[Jeff Rand]

Originally posted by Ricky Trussell
Do you have an IAC opening too much when you put it in gear? Maybe that is causing your idle problem too.

I think you are right on the money with the IAC. I did adjust the TB blade last week. I will check it tonight.
Jeff

 

[Jeff Rand]

Originally posted by Ted A.
The engine starting problems are related to your cranking fuel, after start revs and then the cts enrichment. If you lowered your fuel pressure it may have affected all of these. I know my setup with the 96lb injectors are VERY sensitive to cranking fuel, that has to be right, then the revs are set at around 23 to 20 depending on temperature of the engine. My base pressure is 48psi without the vacuum line. I am at a loss on your problem though. Have you tried anybody elses GCT file? What size motor are you running?

Have not tried any other GCT file yet. I might call the vendor I bought the unit from for another file. The engine size is 270 cu ".
Jeff

 

[Ricky Trussell]

Originally posted by Jeff Rand
I think you are right on the money with the IAC. I did adjust the TB blade last week. I will check it tonight.
Jeff

I went through quite a bit of time with too much throttle follower and tb not adjusted correctly with idle problems. I don't know if you have an auto but if you do I have mine set at 10 at my idle tps setting. It never gets above 13 across the chart. I set my idle speed then with the tb.

I would like to look at your .gct if you could send me one.

 

[QuickWrench]

I hate to ask the obvious question, but...

You mentioned that you've migrated from your Stage 1 engine to the current Stage 2. Any chance that the Fuel Calc Param's are input improperly in CCOM [MAP Bar/Injector Rate]? (I did this once) Also, is the coolant temp sensor/wiring correct, allowing FAST to see the proper temps? This could F--- everything up.

Good luck.

 

[Jeff Rand]

Originally posted by QuickWrench
I hate to ask the obvious question, but...

You mentioned that you've migrated from your Stage 1 engine to the current Stage 2. Any chance that the Fuel Calc Param's are input improperly in CCOM [MAP Bar/Injector Rate]? (I did this once) Also, is the coolant temp sensor/wiring correct, allowing FAST to see the proper temps? This could F--- everything up.

Good luck.

I did change the cubic inches on the fuel calculation and the coolant temp. is connected. The injector size stayed the same (83#).
Thanks,
Jeff

 

[bruce]

Originally posted by Jeff Rand
For some reason my stage 2 is running rich (approx 10.75a/r at idle)

Sounds like you've looked at all the mechanical answers. Can you find another WB, and verify your's is actually reading right?.

WBs when they start to fail read a false rich, and silicone poisoning can cause the problem. Just an aerosol that has silicone in it 30' away from the O2, can in fact kill it.

 

[Jeff Rand]

"Sounds like you've looked at all the mechanical answers. Can you find another WB, and verify your's is actually reading right?.

WBs when they start to fail read a false rich, and silicone poisoning can cause the problem. Just an aerosol that has silicone in it 30' away from the O2, can in fact kill it."

Bruce, I wonder if Speed Pro can check out the WB O2? I will give them a call or I could take the car over to the chasis dyno and use their stand alone unit. Interesting point regarding the silicone. I am not sure if the silicone that I used during assembly was sensor safe.
Thanks,
Jeff