The ECM powering the FP relay is in the hardware, not the firmware. At key-on, engine-off the ECM will run the FP relay for about 2 seconds then shut it off.

Then during cranking, and during engine running, as long as the ECM is getting DRPs, it will enable the FP relay.

If during the engine running the oil pressure switch is disconnected and the engine dies due to lack of fuel pressure. Then there is something wrong with the FP relay/ECM circuitry. The oil pressure switch to run the fuel pump is a redundancy to the ECM/FP relay.

The above functionality can easily be tested.

RBob.

 

Thanks Bob, that confirms what I always was under the impression how it works but, I have to admit, these guys had me rethinking my paradigm

 

Does anyone run EBL with MSD 8366 Distributor? should be a problem to move from stock distributor the the MSD's?

 

Is the HotRST section in Scalars used to prime the injectors and eliminate vapor lock (with KOEO) by running the FP for 25 seconds and CTS above 119.75* C in this case? In essence this can be used instead of the "Hot Fuel Module" HD 5.7L and all 7.4L came with?

 

It doesn't. The fuel pump control via the ECM is in hardware, not the firmware.

The hot restart is intended to take care of the fuel vaporizing and returning to the tank at shut down. Then as new fuel hits the TBI some of it too will flash to vapor.

RBob.

 

Thanks, so what does the hot restart - key on CTS parameter do?

 

Key on temperature threshold for hot restart enable. Only valid if the shut down temperature was exceeded.

RBob.

 

I'm having a problem with shuddering on decel. The shuddering starts when rpm drops to 1600 and lasts till around 1400. The map is around 30-35. I've attached my bin and a datalog. I can't see anything that would this at such a specific rpm.

 

Can you post some time stamps within the log to look at? Note that you can also add markers to the log by tapping the space bar on the keyboard.

I did see some areas of 1600-1400, 35 KPa. The SA seems to be a little high at 36° BTDC.

RBob.

 

3.28, 3.92 and starting at 5.77, there's is a good long stretch. And does ebl only use 2 cells or the ALDroid isn't recording correctly.

 

I'm not sure what the time stamps you posted are in reference to. Use the RunTime column as it is in HR:MN:SC.

As for BLM cells, there are three used: 0 is idle, 1 is cruise, 2 is decel.

RBob.

 

00:08:35 is the long stretch. Thanks.

 

I would say that there is too much SA, in the 35 - 36° BTDC range. In that MAP & RPM area. Drop the SA by 6 - 8° and see how it is. Be sure to blend it into the adjacent areas of the SA table.

RBob.

 

Along with the timing, I also see a few areas in the tune that require some attention as well. My first question though would be regarding the complaint, are we talking actual shuddering or pulsating. Huge difference...

- Rob

 

Actual shuddering. Lowering the SA did seem to help. I want to drive around a little more. What else did you see?

 

When I hear shuddering at a specific RPM, I think of a semi-violent shudder that we would get from a bad torque converter, wheel bearings, tires, etc. But a pulsation, or worse as in a bucking or surge, is normally from a Lean condition. Your Lower VE in that exact area you pointed out (1400 to 1600-RPM and 30 to 35-kPa) has a Lean spot (see below). That's actually one area I seen that needs attention. Also, how much static compression are you running, and how big of a camshaft? I ask this because your Base/Initial SA seems kind of high at 15*...

- Rob

 

I've been letting the VE learn handle things. I've brought up those lean points and smoothed it out. It's a Blueprint engine with 10.3 comp.
Camshaft Duration (.050 in):
230° intake / 236° exhaust
Camshaft Lift (in):
.544 intake / .555 exhaust
10-16 initial timing, When we called Blueprint they said 14-16.

Thanks for looking at this.

 

If you'd like, can work with you to dial it all in in a different way (based on what I am seeing). Would just need a datalog and your wideband volt range. Will take it from there...

- Rob

 

That would be terrific.

Here are my latest bins; 21 is the bin that was used for the data run. 22 is the after bin from VE learn. The data run was over 5mb so I had to use rar.

Voltage is 7.35 to 22.39 5 volt innovate

Could you look at 00:00:35 It died after start up.

 

I already did the Bin, I made some changes following the post that I wrote. My email is below, all I need is a datalog (dat file to be used with WUD analysis) startup from Cold to Hot without touching the throttle at all. I mean you can feather it to keep it running if it doesn't start right up, but then let go as soon as you are able to and let it just idle all the way until warm. The only thing I did not touch yet was your VE and SA Main table. I left the Initial at 15* and Idle State at 24* as well, but I changed everything else so far. When I see the datalog, I will work the VE and SA, will then save those changes to the Bin, then will send it over...

Just send me the warmup datalog whenever you get the chance...

streetlethalgta@gmail.com

- Rob

 

I have a hard cold start issue I've been dealing with for a long time. It only happens first start of the day. Key on, I hear the pump prime, fuel pressure is 43 psi and holds. Crank starter, motor turns but no start. Stop, wait about three seconds, hit starter again and instant start and smooth running. It doesn't matter if it is 40 degrees out or 90 degrees out it just acts like i'm not getting fuel the first time I hit the starter. The tach moves so I am getting ignition pulses. So my first start procedure is bump starter, wait three seconds then bump it again and it is running. This usually works but occasionally it just cranks for a long time before starting. I tried increasing prime fuel but that didn't help. So this morning I did a datalog while starting and it came up with some strange data while cranking. ECM problem? or does the WUD just not report correctly while cranking. Suggestions please.

 

Voltage to the ECM is dropping too low and it is going through a reset.

RBob.

 

[QUOTE=RBob;6443740]Voltage to the ECM is dropping too low and it is going through a reset.

Thank you for your reply. Battery was at 12.4V with my Fluke meter directly on the battery posts. After charging the battery it was 12.65V. I disconnected power to the coil and cranked for about 10 seconds. While cranking the voltage dropped to 10.9V and returned to 12.6V after. I started the datalog and started and stopped the motor ten times. Eight out of ten times I got the same weird data as before at first crank. I even tried it with the charger connected and it did the same thing. I guess next I need to measure the voltage directly at the ECM connector. Which pin do I need to check? Is the reset caused by the battery power feed or or the ignition feed to the ECM? Thank you.

 

You can do this: fire up the WUD, main display. Go to preferences and set the display update rate to 17/second, and the playback rate as low as it goes.

Do a playback of the data log(s) while watching the IGN and PMP gauges on the far left. The IGN is the ignition switch voltage to the ECM. The PMP is actually battery voltage to the ECM {edit to correct: it is the fuel pump monitor voltage. The ECM doesn't read the battery voltage being fed to it}.

The initial hit of the starter is usually what causes the voltage to dip and the ECM to reset.

RBob.

 

[QUOTE=RBob;6443764]You can do this: fire up the WUD, main display. Go to preferences and set the display update rate to 17/second, and the playback rate as low as it goes.

Do a playback of the data log(s) while watching the IGN and PMP gauges on the far left. The IGN is the ignition switch voltage to the ECM. The PMP is actually battery voltage to the ECM.

The initial hit of the starter is usually what causes the voltage to dip and the ECM to reset.

You gotta be quick to catch this but here it is. I'm shocked. Solution? Start cleaning connections?

 

Voltage drop tests are the best way to find out where the issue is. Need either a helper or a remote starter button.

An example is to place a voltmeter between the battery positive post (not cable end), and the starter solenoid post. Engage the starter and note the voltage reading. That reading is the amount of voltage lost between those two points due to resistance in the cabling.

RBob.

 

Wanted to note a correction to my post about the battery voltage:

The PMP is the fuel pump monitor voltage. The ECM doesn't read the battery voltage being fed to it.

RBob.

 

Does the ECM reset at key on every time? I thought it only reset if the battery side was disconnected.

 

The ECM goes through a power up sequence at key-on. There is only some RAM stored with a key-off as long as the battery is connected.

But at key-on the hardware is in an unknown state, same with the non-battery backed RAM. So at key-on the hardware is set up, the RAM is cleared and set up, and a checksum is done on the PROM/Flash memory.

If during set up the ECM decides that battery power was lost, then the battery backed RAM is also cleared and set up.

RBob.

 

I have been having an issue over the last year with a "hesitation/stumble" in the ~3000 rpm +/- 300 say range when i am just on light throttle cruising speed.

I have had good luck with EBL in my other projects and generally in this project as well, but I haven't been able to get rid of this... Doesn't seem like i am in AE as this is pretty much a constant type throttle and while I have altered those tables it didn't seem to make a difference. Seems like when the problem develops it is when i am getting a leaner operation in closed loop in these areas compared to the area right before / right after

I noticed that this only happens when the engine is warmed up and today I forced it to stay in open loop and have no issues at all, although granted my VE table is a little rich all the way around

Engine is a ZZ5 with RAMJET 350 top end, shorty headers, GM TPI type distributor, etc, heated O2 narrowband, etc... My build thread is
https://www.thirdgen.org/forums/engi...t-coupe-2.html

Also interestingly I started out this project with a Holley HP EFI as I was thinking about using that platform for all my swaps, but Holley introduced an error in their software for these types of ignition setups and I got tired of waiting for them to fix it (which they still haven't) so last July 4 weekend I tore it all out and put the EBL P4 in and had it running better in 2 days than the Holley ever ran.

Other than this hesitation it runs great, and in open loop it runs completely super but there must be something i am over looking as no reason this mild engine combo can't run normal closed loop

The file attached is my bin (to force open loop all i did was raise the ECT enable to 140). The two datalogs are one in closed loop (PROM ID 00130) with some markers where i can feel the hesitation and then an open loop datalog (PROM ID 00131) today (no markers and nothing to mark in terms of any problems, but i did a lot of reference running in the 3000 rpm point)

Thanks for any advice

 

I had a similar issue with my 350 TBI. It would surge while cruising at ~2000 - 2200 RPM. While data logging, I saw an occasional jump in RPMs up to 4700 which is impossible. It turned out my ICM was bad and, when warm,was sending random pulses to the ECM which thought the RPMs were higher and thus, changed timing and fueling accordingly causing the surge. My coil was bad too, IDK if the coil caused the ICM to go out or not. They were only ~2000 miles old! I got a good AC Delco D1984A ICM (plus Arctic MX4 thermal paste) and the issue went away! HTH

BTW, I tried to watch your log but couldn't get it to run, probably something wrong on my end?

 

I had thought about other potential issues even the ICM, but i don't think it is anything like that as it seems so repeatable at a certain speed and then only under certain conditions which i began to correlate with it going into closed loop. To then test that I only changed in the .bin forcing through the ECT set point that it stays in open loop. Over the past two days I have had none of the issue in this 3000 rpm that was always there previously. I will continue to run it over the next couple days and if so i know it must be something with the closed loop interaction. I can see in the log it is more lean in this area for whatever reason. If the O2 sensor was having an issue i don't believe it would stick to just this one area, but of course maybe something with the exhaust flow etc that is also consistent

This is an EBL P4 which has a different WUD so maybe you are trying to look at it with the EBL WUD?

 

Hopefully this is in keeping with the theme of this thread... My EBL 7747 TBI has recently started either cranking a long time before starting, or cranking forever and never starting. I wonder is there a way I can use the EBL tools to make debugging this easier? I hear the pump humming, so I suspect something on the spark side of things, or at least in the electronics.

 

Sounds like you may have low fuel pressure, borrow a pressure test kit from your local auto parts store and verify that 1st, s/b 9-13 PSI according to GM but 11 - 13 is better. How long has it been since you did a regular tuneup - cap, rotor, plugs wires?

 

It may be lower fuel pressure, but when it was cranking with no start, there was absolutely no indication of spark, just continuous cranking. I would think if there was spark and any fuel at all it would at least pop/catch once in a while. Just to fill in the story, last night it cranked and cranked with no indication of even trying to start, but then it randomly started this morning. It has been requiring more cranking to start over the last few weeks.
The vehicle is seldom used, so whatever happened likely happened from age and sitting. But to answer your question, it has been many years since the distributor has been messed with. I suspect perhaps the module, which is original from 1983, but then if that was bad, would it run once it started?
I guess I'll go dust off my old EBL/WUD computer and see if I can make it go. Isn't fuel pressure one of the things it would show?

 

The TBI doesn't have fuel pressure sensor/feedback. When you have crank/no start if you sprayed some ether or poured gas down the throttle body, does it start and run? If so, it's probably your fuel pump/filter.

 

I've got a pressure gauge around somewhere I can check it. What's the logic that decides when to run the pump from the computer? I notice it will run the pump when the key is first turned on, but after a start attempt it doesn't run again. Is there a pressure switch or something that controls that?

 

When you turn the key on, engine off, the pump will run for 2 seconds (unless you have the hot fuel module), then when the ECM sees DRPs (Distributor Reference Pulses) from the ICM, it will turn on the pump, otherwise, when the Oil Pressure Switch sees ~4PSI (I think) it'll turn on the fuel pump.

 

Thanks. But why if I turn the key on and hear it run, then turn the key off and back on, it doesn't run for 2 seconds again?

 

There's a delay for ~4-6 seconds before the ECM will turn it back on.

Edit: You need to keep the key off during that delay.

 

Anyone have the 416 head spark table recommended by RBob? I have Dart heads an I'd like to try it. A .bin to use as a compare .bin would be appreciated.

 

The base TBI and port BINs are based on an LG4 with the 416 heads. The SA tables were pulled from an actual LG4 calibration.

RBob.

 

are 2 bar or 3 bar map sensors needed for a crossfire 350 build?

 

No. Only if you are running a boosted application. 1 bar is good for all N/A setups.

 

I have a bunch of old files but I don't have that .bin.

In fact, after looking for it, I think we ought to have a bank of these sorts of files, they can really help.

 

https://www.dynamicefi.com/EBL_Update.php

 

My WB is 0 v = 9:1 and 5v = 19:1. How can I define that so ebl knows the correct AFRs?

 

In the WUD open the User Devices dialog. Create a device using the above values and select that device in the Preferences ADC Channels dialog. The What's Up Display Help document has an example of creating a user device.

RBob.

 

Thank you sir. I have the CD somewhere with the help file, but these days it's hard to even find a computer that has a drive to stick it in.

One more question for now: my tach signal is erratic sometimes, I see it in the data logs and on my analog tachometer too. Why is that? I don't recall ever seeing it do that before.

 

In that case download the update file from our site. Run the .msi file within it to do the CD install. If you have done the CD install on any PC/laptop, the WUD help document is in the EBL Flash Program Group.

Usually a secondary ignition system issue (plugs/wires/cap/rotor).

RBob.