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dthompson
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Hot start on second crank problem

Post by dthompson » Sun Aug 22, 2021 8:03 pm

I'm in need of some help and trouble shooting ideas. I have a rather crazy build, see signature for details. The car runs and drives fine, and even sounds pissed off when the waste gates open! After the engine is up to temp, and you shut it off for a minute, it will not crank on the first try when its warm (180-195F), just turns and turns with the starter. But it will fire almost instantly when you turn the key the second time. The car will fire up just fine when the engine is cold (ive tried a air temps ranging from 50-90F). This seems like a rather simple problem, and I would expect that it would related to the function FN348A, Cranking Fuel PW vs ECT. I have tried a ton of different PWs with almost no perceptible change (from .7ms-3ms). I am working with the assumption that this either has to be a fuel or spark issue. The fuel system is entirely aftermarket, fuel cell, 4303 pump, -10 feed, TFS fuel rails, FID 1600cc injectors, Aeromotive FPR, -8 return. I have tried increasing the fuel pump prime time "Z_FPTM" and it didn't help, so I don't think this is a vapor lock issue. I have observed the gauge on the FPR during priming and the fuel pressure is 40psi while the pump is running (it does go to zero when the pump shuts off as there is no check valve in the system). I have scaled my injector slopes, CID, and break point by 2. I used the numbers FID gave me for those values and I also used their battery offset (but I did not scale that). One thing that annoys me about BE and the QH, is that when I log spark and inj pw, it does not record either of those things until after the cranking cycle, so I cant really see what is happening with the cranking PW to verify. Overall, the MAF tuning (BA5000) is pretty spot on, Ive got the kams trending around .98-1.00 throughout most of normal driving areas. I have yet to run more than a 3psi spring in the gates.

The ISC Dutycycle During Crank FN884 is set to 99.22% for all temps. I've even tried opening the throttle blade set screw more to increase the airflow, but it didn't seem to help either. I have also tried to open the throttle with my foot using light blips to see if that would help during cranking and it doesn't seem to do anything.

As for the ignition system, I am using the EEC and harness from a 92 5.0 Tbrid. It uses a remote, black TFI module on a heat sink located on the lower side of the core support. I have tried swapping it with another new black TFI module and there was no change. The distributor and coil are from a 94 E150 5.8 van motor, that I bought for the original swap. One thought I had was whether the e150 used a gray or black remote tfi module? I'm not sure if that changes anything at the distributor or not? It doesn't look like it to me when I look at the wiring diagrams. Ive wondered if the coil pick up in the distributor needs to be replaced? Ive also wondered if the coil needs to be replaced. However, I would like to diagnose it properly instead of throwing even more money in the pit.

So with that in mind, I did verify that the base timing is correct. It is 10deg using a timing light and the spout connector unplugged. I've tried using a timing light while its cranking and it appears that it does have spark when cranking showing 10 degrees.

Ive noticed that during cranking the VBAT drops pretty as low as 8.9V on the inrush and once the starter is turning the engine at 150-160rpms, the VBAT is around 9.9V. I have also noticed that my factory tach does not display the correct rpm while cranking, it shows 1000rpm instead of 150rpm (it does read correct once the engine is running). This may just be an anomaly, as it had to be modified to work with the V8, and the datalog shows that the EEC is seeing the correct 150rpm during cranking. I'm not sure if either of these things are related to my problem or not.

Another thing I have noticed is that my EEC reads a different voltage than my multimeter on the battery (seems lower by .5V or so). I modified my SC harness so that the EEC gets power the same way the 5.0 Tbird EEC gets power. The battery has been relocated to the trunk with a 1/0 wire running through a disconnect, breaker, and then straight to the starter. I have a 4 ga wire from the starter to the fender solenoid to power the main fuse box, and a 4 gauge cable going to the 240amp mechman alternator. I have a 1/0 ground cable to the floor of the trunk and another 1/0 running up to the front frame rail. A 2gauge ground goes from that spot on the front frame rail to the starter mounting bolt. I also have another ground from the front of the block to the k-member. All the large cables are high flex welding cable. I feel pretty good that the high power cabling is adequate. Maybe the EEC power wire is a little undersized, but IDK.

So with all that said, I'm looking for some ideas and help. I've tried searching forums and the internet with no luck. Have I missed something stupid on the tuning side of things? I have limited experience troubleshooting stuff like this from the mechanical side of things, so any help is appreciated. It seems like this should be an easy problem to solve, but its kicking my butt! I have some videos I can post if needed, but I'm not sure how active this forum really is, so I will wait and see if anyone needs to see something.

Thanks in advance,
Derek
89 Thunderbird SC
427 SBF Twin PTE 6266s, T56 Magnum XL
9.5:1, AFR 205cc, 222/227cam, TFS R intake, FID 1600cc, 93 Pump Gas
EEC=L1C (92 5.0 Tbird), BE/QH, GSALC

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cgrey8
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Re: Hot start on second crank problem

Post by cgrey8 » Mon Aug 23, 2021 6:44 am

I would try to eliminate whether this is spark or fuel. To do that, I'd get it warmed up to the point you know it's not going to start on the 1st try. Then spray some starter fluid into the inlet. If it cranks with starter fluid, then you know spark's working.

My other thought is it's possible 0.7ms is still too large for 1600cc (152lb) injectors. Those are quite large. Even with a relatively mild 331 build and cast iron heads, I've had hot-start problems if I got the starting pulse too large...to the point that the engine wouldn't start even on the second or third try.

It's true that a cranking engine does want a rich mix, but when an engine is hot, they are far less tolerant of overly rich mixes like they are when cold. I did the same as you, and assumed enrichment was what was needed. After it became obvious that was not getting me anywhere, I went the other direction and found the engine liked that FAR better. I think my hot-pulses are somewhere in the sub 1ms range. So with injectors as large as yours, you may want to try getting down into the 0.3ms area and see how well that works...if nothing else more reasonable comes out of this post.
...Always Somethin'

89 Ranger Supercab, 331 w/GT40p heads, ported Explorer lower, Crane Powermax 2020 cam, 1.6RRs, FMS Explorer (GT40p) headers, Slot Style MAF, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, Innovate LC-1, GUFB, Moates QuarterHorse tuned using BE&EA

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jsa
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Joined: Sat Nov 23, 2013 7:28 pm
Location: 'straya

Re: Hot start on second crank problem

Post by jsa » Mon Aug 23, 2021 8:57 am

Hold the throttle flat while cranking, that will trigger de-flood mode. It'll help if it's rich while cranking.

Turn ignition on, start logging, crank engine. BE and QH will log through a start.
Cheers

John

95 Escort RS Cosworth - CARD QUIK COSY ANTI / GHAJ0
Moates QH & BE
ForDiag

dthompson
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Joined: Tue Jan 21, 2014 9:02 pm

Re: Hot start on second crank problem

Post by dthompson » Mon Aug 23, 2021 7:45 pm

jsa wrote: Mon Aug 23, 2021 8:57 am Turn ignition on, start logging, crank engine. BE and QH will log through a start.
I have done this, but it doesn't start recording any values for spark or PW until the engine fires. Stuff like RPM, VMAF, VBAT, TP... those scalers are all registering in the log. Its as if the EEC handles the cranking spark and cranking PW different and its not showing up in the logs until after it fires. See example image below.

SECOND CRANK.jpg
SECOND CRANK.jpg (55.85 KiB) Viewed 777 times

I don't know what to make of the dip shown in the ECT right at the beginning of the cranking. It doesn't always do this when the hot start problem happens, but I do see it a good bit in the logs. It appears something is happening at that point in time as the ECT, ACT, TP all drop at that point. Its at that same point where the VMAF starts to increase. Its just odd, because the rpm doesn't start moving for another few data points. I zoomed in on the dip in case what I'm describing is weird, see detail of example image below

SECOND CRANK DETAIL.jpg
SECOND CRANK DETAIL.jpg (62.79 KiB) Viewed 777 times
That makes me wonder if there is some sort of electrical gremlin hiding somewhere.

I'll try some of these other ideas mentioned above. I like the starting fluid idea, I can pull the fuel pump fuse and just spray some starting fluid into the TB and see what happens. I'm all out so I will pick some up tomorrow.
89 Thunderbird SC
427 SBF Twin PTE 6266s, T56 Magnum XL
9.5:1, AFR 205cc, 222/227cam, TFS R intake, FID 1600cc, 93 Pump Gas
EEC=L1C (92 5.0 Tbird), BE/QH, GSALC

jsa
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Joined: Sat Nov 23, 2013 7:28 pm
Location: 'straya

Re: Hot start on second crank problem

Post by jsa » Mon Aug 23, 2021 8:33 pm

Ok, lack of spark and Inj PW until running is a definition file issue. Payloads need to be identified and added to the definition.

Spikes and dips...two things.
1. Capacitors filter that sought of thing out. Check out the caps in the EEC, they may not be keeping the sensor 5v feed stable.
2. Cranking goes from 0 amps to hundreds of amps in an instant. That creates a big rapidly expanding magnetic field. That will induce all sorts of interference into nearby wiring. Keep sensor wiring away from the starter cable as much as possible.

Edit...
Maybe the ignition sw is dodgy. Breaking supply to the EEC as the key rotates from on to start.
Cheers

John

95 Escort RS Cosworth - CARD QUIK COSY ANTI / GHAJ0
Moates QH & BE
ForDiag

dthompson
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Posts: 16
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Re: Hot start on second crank problem

Post by dthompson » Thu Aug 26, 2021 10:06 pm

I just wanted to share some thoughts even though I have not solved the issue yet. I really appreciate the suggestions as they have spurred other ideas to try.

I got in touch with Sailorbob and he helped me out by updating the strategy to add the cranking pw payload. Hats off to him, he had it back to me in less than a day. So that is logging now, and things seem to be working. That's a big help so I can look back at all the different PWs I've been trying.

I was using a USB hub to connect the QH and my wideband to my laptop and the hub took a poop on me. I found some a to c adapters and was able to do some testing tonight. In the process of trying to figure out if it was the hub or a cable, I pulled the EEC out to replace the cable. While it was out, opened the case up and inspected the caps front and back with a magnifying glass, but I didn't see anything wrong with the EEC.

I purchased an inline ignition tester, the little deal that you can plug inline between the coil and the distributor and it lights up/blinks red to show you that the ignition is firing. The tool lights up/blinks red when the no start condition happened. And it lit up red when the car cranked and ran. So there is spark the best I can tell.

So it seems like a fuel thing...maybe or maybe not? Once the car was up to about 180 degrees, I shut it off and started trying different PWs (again) and I started low at .38ms. It wouldn't start after a few cranks. Then I tried, 1.3ms and it didn't start on the second try, then 2.5ms and it didn't start on the second try, then I tried 3ms and it finally fired up (it wasnt pretty, it made 900 rpm, then back to 400rpm, then up to 1200 and settled out). After looking at the log there is a spike like at the very first injector PW recorded, That spike was a 2.9ms and the very next data point was 0.9ms. Unless that 2.9 is somehow carried over from the cranking pw to the inject pw in the transition... I did see the spike happen like that in another log at a higher cranking PW and it was very close to the cranking PW value too. I went on to try larger PWs, and I saw the same symptoms of cranking instantly on the second start. I went on to try 3.5ms, 3.75ms, 4ms, 4.5ms, and 5.0ms. same result every time, nothing at first... fires instantly on the second try. And it really didn't struggle other than that first time it fired.

So I moved onto the ignition switch suggestion. I decided that I would bypass the ignition switch by leaving the key in the on position and crank the car by jumping the starter solenoid on the fender. I thought that fixed the dips mentioned in the previous post, but I later saw the same dips. But this really made me think. I've been using BE and QH for several years on a few different engines and I've never seen this type of dip before. On this twin turbo build relocated battery to the trunk. And somewhere along the way struggling with this cranking issue, I rerouted the main 1/0 cable straight to the starter from the main disconnect. Then there is another cable from the starter to the fender solenoid to power the main fuse box. The alternator also is wired to the fender solenoid. But as I thought about this compared to how things were before I relocated the battery. The fender solenoid was connected straight to the battery. which means the main fuse box and everything else, including the EEC power (relay), was essentially connected directly to the battery. Now, everything is connected to the starter, so the EEC is on a really dirty bus.

I'm going to try to come up with a way to power the EEC directly from the battery to test this theory out this weekend.

Not sure if you guys have any other suggestions, but I really do appreciate the help so far.

Thanks,
Derek
89 Thunderbird SC
427 SBF Twin PTE 6266s, T56 Magnum XL
9.5:1, AFR 205cc, 222/227cam, TFS R intake, FID 1600cc, 93 Pump Gas
EEC=L1C (92 5.0 Tbird), BE/QH, GSALC

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cgrey8
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Re: Hot start on second crank problem

Post by cgrey8 » Fri Aug 27, 2021 6:42 am

This discussion is bringing up memories I had about a similar problem I eventually made peace with in my early days of tuning. When my truck was a 2.9L V6 (batch fire and no MAF), the engine would fire up with a quick blip of the ignition. It was impressive how easily the engine would catch and turn over.

And then I got to realizing for all these years, I've probably been dealing with the same exact issue you are trying to understand and solve. Neither of the V8s I've had in the engine bay have started this easily. While I can get the engine to start with a single-crank, it takes a LOT longer on the starter for the engine to actually pick up and start vs if I give it a typical 1-second or so start...no run. Then try it again, and it fires right up. I even added time to the fuel pump prime-time to see if just giving the fuel pump a few more seconds to build pressure and clear the line might help. While I was running an adjustable FPR, that did help since the aftermarket FPR I had would bleed fuel down quite quickly. But stock 96-97 Explorer FPRs seem to hold pressure in the line for hours.

The other thing I recall is that as a 302, I remember being able to push-start the engine and get the engine started much faster than if I used the starter (manual trans). But for whatever reason, the 331 doesn't start this easily. Even push-starting the engine, I have to roll a bit down a hill with the trans in 3rd before the engine will start that way OR I can dump the clutch twice, and it'll crank on the 2nd dump. It's almost as though it just needs "time" to start. The difference between my scenario and yours is, this behavior exists for me cold as well as hot.

If you could, see what happens when you hold the starter on longer for the "first" crank...5-6 seconds. Will it eventually start? And if you have a fuel pressure gauge, it might be interesting to confirm that you have full fuel pressure during the cranks (I suspect you do, but it eliminates a problem getting that confirmation). And if you have a spare FPR, it might be interesting to see if you get different results with a different/stock one.
...Always Somethin'

89 Ranger Supercab, 331 w/GT40p heads, ported Explorer lower, Crane Powermax 2020 cam, 1.6RRs, FMS Explorer (GT40p) headers, Slot Style MAF, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, Innovate LC-1, GUFB, Moates QuarterHorse tuned using BE&EA

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dthompson
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Posts: 16
Joined: Tue Jan 21, 2014 9:02 pm

Re: Hot start on second crank problem

Post by dthompson » Sat Aug 28, 2021 12:29 pm

WOOT WOOT! I think the dirty power was the issue. I had the EEC grounded to the same place as several other things on the front core support (where the battery use to be). I disconnected the ground from the chassis and I disconnected the EEC power relay output from inside the power distribution box. Then I used jumper cables and connected the EEC power and ground directly to the battery. I set all the cranking PWs to 3ms, just cause 3ms seemed to like that previously. The car fired up in 1 second, not bad. Then once the car was warmed up to about 180deg or so I shut it off. Waited a minute or less, then cranked again. fired up in less than 1/2 second. Repeated this 5 times and it fired up within a 1 second every time. I varied the PWs a little just to see since things seemed to be working and when I reduced the PWs below 3ms, it seemed to take longer to crank. After reviewing the 6 logs, there was not a single dip in the data during cranking like there was before. Im also noticing that the VBAT is now around 10V at its lowest spot while cranking. Before, it was not uncommon to see the VBAT drop below 9V during cranking, but now the EEC is now getting 1V better than it was before. Plus the fact that it starts so much faster now, its not using so much of the battery.

I really want to thank you guys for the help and ideas. Sometimes just writing it out and discussing it makes you think about things more critically than you would otherwise. Now I just got to figure out how to redo my wiring and put some miles on this beast. It will be nice to trust the car again!
89 Thunderbird SC
427 SBF Twin PTE 6266s, T56 Magnum XL
9.5:1, AFR 205cc, 222/227cam, TFS R intake, FID 1600cc, 93 Pump Gas
EEC=L1C (92 5.0 Tbird), BE/QH, GSALC

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cgrey8
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Re: Hot start on second crank problem

Post by cgrey8 » Mon Aug 30, 2021 6:14 am

I'm amazed that grounding was the fix for this. I don't think I would've guessed that. But good to know.

Ground issues cause all kinds of odd and unpredictable behavior, so I shouldn't be surprised. I just wouldn't have thought this would be one of those cases where ground was the culprit.
...Always Somethin'

89 Ranger Supercab, 331 w/GT40p heads, ported Explorer lower, Crane Powermax 2020 cam, 1.6RRs, FMS Explorer (GT40p) headers, Slot Style MAF, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, Innovate LC-1, GUFB, Moates QuarterHorse tuned using BE&EA

Member V8-Ranger.com

dthompson
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Posts: 16
Joined: Tue Jan 21, 2014 9:02 pm

Re: Hot start on second crank problem

Post by dthompson » Mon Sep 20, 2021 9:09 pm

just a little follow up... I happened to find that my intake manifold bolts were loose as well. That's why the cranking pws were so high. I'm glad I went through all these exercises though. I'm pretty sure that the EEC power wiring was a problem as well. An interesting combination for sure. Headed in the right direction now!
89 Thunderbird SC
427 SBF Twin PTE 6266s, T56 Magnum XL
9.5:1, AFR 205cc, 222/227cam, TFS R intake, FID 1600cc, 93 Pump Gas
EEC=L1C (92 5.0 Tbird), BE/QH, GSALC

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