Engine Bogs while cold and when shifting from 1st to 2nd.

[JRam76]

I have the Terminator X V2 on my Ford 347 roller block. Main configuration is a Hi-Ram manifold with a 90mm TB, AFR 195 heads, Mid length headers, a VooDoo cam with Duration @ .050 (Int/Exh): 231°/239°; Gross Valve Lift (Int/Exh): .571"/.587"; LSA/ICL: 110°/106°. When running cold, I have a sizable bog when shifting from 1st to 2nd on TCI Street Fighter C4 transmission. The engine runs quite strong overall in a higher RPM and under load. This only happens when coolant temp is about 135°F or below. I can technically wait until it warms up completely to run the car, but think it shouldn't have this issue in general. During hot weather or when the car is running at temp of about 190°F, the problem goes away. This is more of an annoyance.

Based on the datalog files, I can see where the Closed Loop Compensation goes from -25% to 30% and at the same time, AFR goes way over 35 and finally settles back when the bog goes away. This is sort of a short-lived 1-2 second bog as it transitions from 1st to 2nd. I attached a screenshot. I tried uploading my datalog file, but apparently couldn't through this post. Anyone have any ideas?

[GPatrick]

You have to zip the files in order to post them here. We need to see the Config File downloaded from the ECU (use the Save As function) as well as the datalog.

What have you done with your Injector End Angle setup? I have a similar cam on a 347 and it had bad manners when cold at idle, off idle, and mild acceleration when using a straight -90° for the Injector End Angle.

[Danny Cabral]

My Injector End Angle table is -150° at idle/low RPM, and ramps down to -220° at WOT RPM.

[GPatrick]

To semi-hijack this thread. Danny, are you using the MAP versus RPM table or the Pulse Width versus RPM method? What's your max RPM scale on the table as I may need to adjust the numbers based on my currently somewhat conservative max RPM of 6500. We're going to have some warm weather tomorrow and I'd like to do an A/B comparison as I continue my engine and drivetrain break-in. I've setup the Pulse Width versus RPM table and it's much better than the straight -90° Injector End Angle, but I'm interested in trying other methods.

[Danny Cabral]

To semi-hijack this thread. Danny, are you using the MAP versus RPM table or the Pulse Width versus RPM method?

The default EFI software RPM x MAP kPa IEA table.

What's your max RPM scale on the table

One column under idle cell to the WOT RPM (7000 RPM).

[GPatrick]

Thanks on which table and the clarification. I should've been more clear on the RPM. My RPM range goes from 500 to 6500. If your X axis RPM goes from 500 to 7500 do I need adjust the WOT IEA value slightly or does it matter? As usual, I'm probably over thinking it, especially without a dyno to optimize.

[Danny Cabral]

Yeah, that RPM scale is fine. Just ensure it's the same value in the idle area, so it isn't changing IEA while idling.

[GPatrick]

Perfect, thanks again!

[JRam76]

I attached my Config File and also my datalog files from the last run. I didn't do any WOT since the problem is down in the lower RPM. Regarding the question about the Injector End Angle, I used the sort of built-in smart tool where you enter cam specs to obtain a baseline Config File. Please let me know if you find any strangeness in the files. I'm relatively new to the EFI systems, although I worked on many carburetor type setups in the past. Overall, the engine runs really well once warmed up, especially in the higher RPM. Certainly something to be said about EFI. It's just that spot on the 1-2 shifts. Any help would be appreciated. Point me in the right direction and I will do my best to solve this issue. :-) Much appreciated and Happy Thanksgiving everyone!

[GPatrick]

Based on my research through past posts and some of my own limited experience I think you need more injector end angle in the idle region. I would suggest two quick test Config Files. In the first, using the EFI software, change the injector phase offset to 70 (it's currently zero). This will change your Injector End Angle to about 150 in the idle area. Save that as test number 1 For the second, enter the values that Danny provided in post # 3. In this method, set the offset to zero. Then build a table starting at -150° and ending at -220° in the first row. If you enter those two values and then right click on either one and select "Fill Row Values" it will evenly space the values across the range. You can then copy & paste that row to each row in the table. Don't press on recalculate or it will overwrite your new table. Save this one as test # 2.

Report your results. There's an alternate method using a Excel spreadsheet and a 2D Advanced ICF Table that has worked for me, but it may not be necessary if either of the two methods above work. The biggest impact on my engine with better Injector End Angles around idle, was off-idle and light acceleration. It also significantly reduced the raw gas smell I had when I first got it running.

[JRam76]

I tried both tests.
Test 1: Simple table with -150° to -220° from idle to 7000 RPM split evenly throughout the range. Table was not recalculated to preserve configuration.
Test 2: Injector Offset of 70 which put the idle area to around -150° after a recalculation.

Test 1 was worse than my original setup where the engine almost shutoff between shifting from first to second.
Test 2 behaved like my original setup. I'm going to try another test and will report my results.

One thing is certain in that this setting has a sizeable effect on idle to transition. Another bit of information is that going through the idle adjustment is quite sensitive in that I try to accomplish the results as mentioned in some of the instructions Danny posted in the past. The adjustments get as close as possible to ideal where the IAC does the bulk of the work at idle as appropriate. Do you think the idle adjustment is very sensitive perhaps due to size of injectors, size of throttle body, or due to hi rise manifold. The injectors size is 48 lb/hr. My engine puts out roughly 500 HP at the crank. I limit the RPM to 6450 as it will certainly go over that easily and I don't want break anything. :) I believe the mid to top end is very strong, but the idle and transitioning is just not where it needs to be in my opinion. Thoughts? Much appreciated.

[GPatrick]

There has been a fair amount of tuning on the config file and I don't know the history of your tuning changes. There are a few things that you might try to see if it reacts better or worse:

1) The ignition shows a Reference Angle of 50 and an Inductive Delay of 100. On both of my Fords, the Inductive Delay was too low. On the 347 with a dual sync I have my Inductive Delay set at 150. Using the handheld set the Static Timing to 20°. Verify the timing at idle just to confirm. Gradually increase RPM while watching the timing. If the timing dips below 20°, your Inductive Delay is too low. Try 150. If the timing increases this time, the delay is too high so drop it down in steps of 10 at a time. If the timing still dips then the delay must be increased. Not that you'll encounter this in your case, but the delay on my FE dual sync is 325. You can easily have a timing error of five degrees when the delay is set too low. The LED setup alone can have 10 or more degrees of error even if following the procedure to the letter.

2) Not knowing your engine and your experience, I think that you may want to experiment with your idle settings a bit more. I would, for a test at least, set the RPM To Start Ramp up to 800 from the current zero and the RPM Above Idle To Re-enable Idle Control to 50. This may influence your first/second shift and may be worth a try. You may also want to experiment with your IAC Hold Position a little more. You can confirm with a datalog, pay attention to what the AFR shows when you give it some throttle. Once you hit 2% the IAC Hold Position will kick in and for your engine 20% may be a little high. You could try 15 or even 10 percent to see if it gets better, worse, or stays the same. Also, you have the Advanced Idle Control set to Slow and you may find that will affect how the engine reacts just as you are leaving idle with the TPS below 2%. Just throwing it out there, but a faster reaction from the IAC may help.

3) With just slightly less cam (about 2° I & E) my engine will idle pretty well at 900. You have yours set at 1185. Again, without hand-on experience, this seems a little high to me. But, based on your heads and intake that may be where it has to be. But, for a test, change the target idle speed to 500 and disable Idle Spark control. Using only the idle screw decrease the idle speed while watching the MAP/kPa reading on the handheld. Alternatively you could use a vacuum gauge out at the engine. Observe where the you lose significant vacuum. You may find that creasing the idle speed to 950 or 1000 you have a little more control with the IAC. You may have done this already. But if you have had to adjust your timing after checking the distributor sync, it may behave a little differently with different timing. If the vacuum falls off a cliff at 1150 then your current idle may be where it is supposed to be. Re-enable idle timing control and change your target idle speed as appropriate after this exercise.

4) Your Base Timing Table may need some tweaking in the future. The idle area timing is pretty consistent, but it appears that you may want some more timing in the cruise area and the engine may respond better with WOT timing coming in at 2800 to 3000 RPM. Right now you don't hit your WOT timing until 4250 RPM. If you combine this with an incorrect Inductive Delay you may be leaving some performance on the table.

Andrew70B on this forum may be able to assist with a remote tune. He has vastly more experience with these systems. I know that your initial question was related to some cold operation, but it does appear that the overall performance may improve with some refinement.

[JRam76]

I really appreciate your input. I'll certainly give your option 1 an attempt. I checked it previously and it was rather stable throughout the RPM range without going overly high on RPM. I believe you may be on the right track with option 2 and will give that an attempt for sure and report results. I recall that when I first started with a base file with little to no major adjustments, the problem was not as pronounced. I'll look at some old files. I believe a combination of old file configurations at the low RPM transition area and newer file configurations at the higher RPM may be the ideal settings. I'm now curious if the older file resembles the adjustments you listed in option 2.

Regarding option 3 with the idle, the combination is what I believe requires the higher RPM. As soon as I put the engine in drive, the engine wants to bog down. I don't think the IAC kicks in fast enough to hold the idle high enough to stay on. I believe the lowest I can go without too much trouble is about 1000 RPM.

Regarding option 4, I'll adjust the timing to see how it reacts.

I'll try the adjustments separately to avoid adding too many variables at once. I set the Injector End Angle to the original state to remove that variable.

By the way, I set the Phase Angle to something completely different as my 3rd attempt, as I mentioned earlier, made the engine quite a bit more responsive on the transition, but the bog was still present and may have slightly improved overall. The Offset setting was -150°, which put the idle area at +70 roughly. However, I believe I'm throwing a Band-Aid to the root cause. I will try the other options you mentioned. Thanks again.

[GPatrick]

Slow IAC control could potentially cause the system to not react quickly enough when you put it in gear. Along with all the other tests/trials, capture a warm datalog of the engine at idle for 10 seconds and then drop it in gear. It will be helpful to see what the system is doing to try to recover your idle speed.

What are you running for a PCV valve currently? Check all vacuum connections to make sure the only air entering the system is from the throttle body/IAC other than a controlled leak from the PCV.

[JRam76]

You were on the right track. Some things may tend to resolve themselves by pure luck and from people like you. :-) I took my car for a cruise this morning and felt like pushing the pedal to the metal a bit. This time, however, the engine decided to rev a bit strangely after that event and kept running at 1800 RPM at idle and in gear. I knew something went wrong suddenly. I drove it home like this, but luckily only about 1/2 a mile. I looked at the file datalog for strangeness and everything seemed normal in terms of recent datalogs, with the exception of the lean spot between 1st and second which I knew I had. I went back to inspect the engine, specifically for vacuum leaks based on the over revving. I was really surprised to see that the throttle body came loose and wondered how long that's been that way. The bolts are rather long and 3 out of 4 came out. The last bolt was about 1/4" out already. See pictures! Not sure how the screws would have backed out that much, but recall that I had to drop the engine down by about 1/2 inch to clear the hood when revving since I noticed the air intake assembly would hit the hood when revving. Over time, vibration and jarring would cause the bolts to slip loose.
There's a great amount of air leaking through the gap now which explains the high revs. I can imagine that if a slight opening on the throttle body was present, it would be more pronounced when shifting since the air filter taps the hood between first and second while cold. A small amount of air going through will certainly cause the bog. If the rubber intake tube is cold then it's stiffer and not as flexible. When the rubber intake tube is hotter, then it should flex easily, but not allow the throttle body open as much, hence the improved idling and transition while the area is warm. I'll put Lock-Tite on new bolts, recalibrate, and retest to see if this was indeed the culprit the entire time and got worse over time. I never would have though bolts came that loose. Now that I think about it, I heard sometime fall off the car that sounded metallic as it hit the under body recently which I'm pretty sure it was the throttle body bolts.