Rusty has a FUEL INJECTION HICKUP

First she starts and runs at 623 rpm GREAT! But when I tried to rev the engine things fell apart. Initially it would rev but then, about 1000 rpm, it cut out ~ like the FI turned off ~ and just as it was going to stall, it'd turn back on (like someone was playing with the ignition switch) ~ then idle perfectly again. Tried again, it'd do that a couple times and then stall on a compression stroke ~ this caused the engine to turn about 1/4-1/2 turn backwards pushing a fair amount of air/fuel backwards out of the throttle body. A geyser effect.

I cranked again, it fired right back up, tried to rev it, and the same thing. I checked the timing and it looks like it's set 5-10 degrees PAST TDC :confused: ~ Here's the thing. The timing marks are messing with me. From passenger-to-driver side there is a 20, 10, 0, and 5 mark on the cast peice. The scout runs at about 5-10 degrees PAST the 5 mark ~ isn't that the ATDC area? I have a fancy timing gun and the more I advance the light, the farther it goes AWAY from the marks! :confused:

Assuming I'm crazy, I adjusted the timing back, the best I could get was about 0-5 degrees on 20-0 side of the marks. It seemed to run better the more it was aproaching 10. Then before the fuel system would again choke and then the engine would do its 'geyser' impression immediately. I tried to fire it up and nothing ~ it'd try to start but instantly blew air/gas out the TB. So now I"m really confused.

The biggest thing is the FI literally turning off until just before it stalls ~ then firing and keeping it running. Really annoying. Anyone got any suggestions?

Oh, I will say that there is some vacume leaks, I need to reseal the TBI to the manifold (when it 'geysers' you can see a little shoot out from under the throttle body) ~ not sure how that got a leak, but I'll take care of that. Also, there is NO O2 sensor yet, that get's put in with the exhaust. the sensor is not even plugged in yet.

Could the lack of an O2 sensor really cause that spuddering? I have 'Coop coming by on Tuesday (he's my master mechanic) and he's going to spend some time with me testing things, but if I can get this thing running before I drop it at the exhaust appointment (tomorrow) it'll be easier to pull it on and off the trailer!

When I first had mine running I did not have an 02 sensor or a throttle position sensor. Because of no tps I could not really rev it like I wanted too, I had to sorta lean into it. (No mashing the gas)

I don't have my v8 scout nearby so I can't check my timing marks, but I can ask that you are timing from the number 8 cylinder, right?

Since you have the fancy light with the advance-o-meter knob, set it to whatever you want your timing to be at and then line up the 0* marks.

I should have asked, does your ecm control spark? If it does I *think* it has to be disconnected and set to 0*. Someone else will have to verify that though.

Yes, the tan wire needs to be disconnected to set the base timing. I would start at 0*. Isnt that an AFI set up? maybe you should call them.

Sounds like the same symptoms I had on a rig I worked on last week. Brand new DUI distributor had a bad ignition module. Not sure if you are running computer controlled ignition or not.
________
How to roll a joint (http://howtorollajoint.net/)

Well you didn't say what system configuration you have but based on your description it sounds like a timing issue.

The FI only works when it recieves a signal from the EST. The computer looks for the DRP-distr ref pulse to ensure there is spark before it fires the injectors.

So if the ignition breaks down or overheats it will become intermittent.

The other problem is your timing.
If you are computer controlled then the timing is set to 0° with the bypass disconnected. But if it's hooked up most are set right around 15°BTDC.


If you can not achieve these timing settings without problems then either the ECM/EST are sending the signal at the wrong time or you are timing on the wrong wire.
What about a knock sensor?
Are you running one?
Is the retard table zero'd out if your not.
Is the map sensor reading right?
Did you do the voltage checks listed on sheet 1 of the wiring diagrams?

The third less likely would be a cam gear.
But given the other indications I would say no.

I assume since you sell and install these systems now that you have a laptop to log and diagnose data.

If you have some logged then post it up.

As for the other issues.
Vacuum leak needs to be fixed but shouldn't cause you immediate problems.


O2- This should only come into play if the initial fuel tables aren't even close.
The system will operate in open loop with out it.
If your system is tuned properly you could run with out the O2 just like a carb.
But it will run like a carb...no real time AFR adjustments.

Well you didn't say what system configuration you have but based on your description it sounds like a timing issue.
DUI dissy, was working perfectly when I took rusty down for the 'big' change, AFI Stage II, basically your standard TBI conversion kit with all the sensors. NOT COMPUTER CONTROLLED TIMING.


If you can not achieve these timing settings without problems then either the ECM/EST are sending the signal at the wrong time or you are timing on the wrong wire.
Timing on #8, passenger side, rear most cylinder

What about a knock sensor?
Are you running one?
No.

Is the retard table zero'd out if your not.
Not sure what a retard table is, if youre talking about the timing light, I'm not using the advance feature....just straight timing as it is.

Is the map sensor reading right?
I have to assume so.

Did you do the voltage checks listed on sheet 1 of the wiring diagrams?
No, didn't even think of it. I checked for good ground and still does it.

The third less likely would be a cam gear.
But given the other indications I would say no.
Ya, I doubt that.

I assume since you sell and install these systems now that you have a laptop to log and diagnose data.
Mark (aka Coop) is coming over Tuesday to hook up the little thingy ;)


As for the other issues.
Vacuum leak needs to be fixed but shouldn't cause you immediate problems.
They are small, very small vacuum problems, I didn't think they'd give me any super big problems

O2- This should only come into play if the initial fuel tables aren't even close.
The system will operate in open loop with out it.
If your system is tuned properly you could run with out the O2 just like a carb.
But it will run like a carb...no real time AFR adjustments.
that's what I figured, but wanted to make sure.

Great idea on the voltage. I'm going to check the power hitting the DUI and AFI at all available RPM, perhaps the feed wire is not getting the voltage needed and when I blip the throttle ~ or try to rev it ~ it fails and then picks up when it can.

Thanks Bill, wasn't sure if you monitored this board..

No computer controled spark.

IHOJeff, The dissy had served me VERY well until I parked and torn into Rusty. Given that's 2 years ago, but I have to assume it's still ok....for now.

Sell the DUI and use the $$ to get the computer controlled spark part of the system. You will be glad you did. I like the MSD Blaster SS coils since the small cap hybrid distributers do not have coil on top setup.Curious what a AFI stage 2 is???:confused: I have installed the AFI full system 12 or so times now and they have never mentioned the stage 2:confused:

Oh and if ya read the instructions AFI provides they tell you to smear a thin coat of sealer on both sides of the TBI to adapter bracket to eliminate the possibilty of vaccume leaks;) That should solve the leaks.

I would put a voltmeter on pin B5 of the ECM.
According to Sheet 1 of the ECM pin out diagrams it should have 0V with key on and 1.6 volts with engine running.

Now if you can monitor this voltage while you are experiencing the cut out...I think you may find it is dropping this signal.

If it is then you need to look back towards the tach filter and the dist ign module.
If it's not dropping this signal then you may be looking at an ECM.

Can you use your timing light to watch the fuel shooting from the inj's when the problem occurs?

It would help to know if you are just losing fuel or spark or both.

Sell the DUI and use the $$ to get the computer controlled spark part of the system. You will be glad you did.
I thought about it but don't have the money. Its time to get Rusty running with what I have.

Curious what a AFI stage 2 is???:confused: I have installed the AFI full system 12 or so times now and they have never mentioned the stage 2:confused:
Instead of making customers remember part numbers, I gave them new names. Stage 1 (IH1100) is the DIY kit. Stage 2 (IH1200) is the one I have that comes with everyting you need (not computer controled timing), and stage 3 is the IH1300 or complete system. Basically I took the 1,2 and 3 from the part numbers.:D

Oh and if ya read the instructions AFI provides they tell you to smear a thin coat of sealer on both sides of the TBI to adapter bracket to eliminate the possibilty of vaccume leaks;) That should solve the leaks.
Did that, also kept the gasket in place. Appearantly I didn't do enough.

I would put a voltmeter on pin B5 of the ECM.
According to Sheet 1 of the ECM pin out diagrams it should have 0V with key on and 1.6 volts with engine running.

Now if you can monitor this voltage while you are experiencing the cut out...I think you may find it is dropping this signal.
My first plan is to monitor the ignition voltage to the dissy when it happens ~ so make sure the dissy isn't hickuping ~ I doubt it since it has always worked, but you never know. Then I'll check the supply voltage to the TBI system ~ to make sure its getting voltage as it should. Then I'll check this voltage and the tack filter. I'll be honest, I hope its a bad ground or something easy like that.

If it's not dropping this signal then you may be looking at an ECM.
This would be another best-case-senario ~ as the ECM would be easy to replace.

Can you use your timing light to watch the fuel shooting from the inj's when the problem occurs?

It would help to know if you are just losing fuel or spark or both.
Fuel stops when it happens ~ already confirmed that.

What makes me scratch my head is that I can get it to cut out by adjusting the timing. :confused: I need to watch the tach and see if the tack goes dead at the same time. Like i said, if this is a simple 'power starv' problem I can run a clean power.

I would put a voltmeter on pin B5 of the ECM.
According to Sheet 1 of the ECM pin out diagrams it should have 0V with key on and 1.6 volts with engine running.

Now if you can monitor this voltage while you are experiencing the cut out...I think you may find it is dropping this signal.
My first plan is to monitor the ignition voltage to the dissy when it happens ~ so make sure the dissy isn't hickuping ~ I doubt it since it has always worked, but you never know. Then I'll check the supply voltage to the TBI system ~ to make sure its getting voltage as it should. Then I'll check this voltage and the tack filter. I'll be honest, I hope its a bad ground or something easy like that.

If it's not dropping this signal then you may be looking at an ECM.
This would be another best-case-senario ~ as the ECM would be easy to replace.

Can you use your timing light to watch the fuel shooting from the inj's when the problem occurs?

It would help to know if you are just losing fuel or spark or both.
Fuel stops when it happens ~ already confirmed that.

What makes me scratch my head is that I can get it to cut out by adjusting the timing. :confused: I need to watch the tach and see if the tack goes dead at the same time. Like i said, if this is a simple 'power starv' problem I can run a clean power.

what kind of fuel pump are you running? it may not pump out enough pressure to fuel the engine at a high rpm... just wonderin, i dont know much bout efi's so just one thing it may or may not be..

I don't think so, its the pump that came with the kit.

I don't think so, its the pump that came with the kit.

see if thats leakin though... i mean you said you took it out of rusty a couple years back... so gas may have cracked some seals.. or somethin in the pump...

This is a new install on the TBI, the TBI hasn't been sitting long.

What is the condition of your fuel filter?

Well I think you said it happened when you adjust timing? when the distributor is loose so is it's ground. Tighten the distributor and see...

Check the fuel presure and see if it drops off when you accelerate.

How much welding have you done on this truck with the ECM still connected?

I returned your call and left a message friday...

How much welding have you done on this truck with the ECM still connected?


That's a good one!!:eek:

Filter is new, but I think Mark may have hit it...
Well I think you said it happened when you adjust timing? when the distributor is loose so is it's ground. Tighten the distributor and see...
Tried that.

Check the fuel presure and see if it drops off when you accelerate.
Will do as soon as it gets back from exhaust.

How much welding have you done on this truck with the ECM still connected?
I have a battery cut-off that disconnects the ground when switched, I've not really turned it on at all, but I wouldn't be surprised if there was a little welding done whe....

.....Uh oh. :shaking:...

I ran a special ground so that the computer never looses power ~ Norm or you said I should do that to make sure that the computer doesn't have to start fresh after every run. The way it was explained is that the computer keeps a history and when you cut ALL power it needs to re-learn or something so the recommendation was to run its own ground that will allow it to retain whatever it keeps. That power is off the starter terminal (always hot) and the ground I ran ONLY goes to the computer, nothing else.

Do you think that could have fried it? Crap~ I think I know what your answer is going to be.:mad3:

I returned your call and left a message friday...
Thanks. I'll call ya.

While it is possible to fry it by welding, I have welded on mine with it hooked up.
I installed a complete new exhaust all welded.
Ran an extra bead around the front spring mounts, and I also run an OBW that I have used on my own truck.

So keep in mind it is only one possibility.

And it would help more to keep the discussion on the front channel.

The front channel?

online...here..

Not back channel on the phone or email.:)

He started it! :D

I agree with the welding, don't know why some fry and some don't. Could be position of weld, ground and power used. I always ground to engine block, that's where the negative cable is. Maybe it has to do with trucks that have better ground straps to engine from frame since it's basically isolated with motormounts... all theory though... Have to look at it with all the welding he has done.

I've done extensive welding on my rig with the ECM hooked up. Welded in the seat base/cage tie-ins, cage to frame tie-ins, slideres, and various mounts here and there..... not so much as a hic up out of the ECM.

Hmmm, I have done a fair amount of welding on mine as well. That might explain my intermitant issues. So does it ruin the just ECM or ECM and chip?

Here's a video I have of it idling with the new exhaust. You can hear the hickups.

www.dandcextreme.com/upload/rustystall1.MOV

PROBLEM SOLVED! IT WASN'T THE TBI!

DynaModule in the DUI went out, I guess the electronics don't like welding/plasma cutting. I knew it had to be something stupid and easy. While Mark was here we started looking over things, found a few things that I didn't notice before, but nothing cured the hickup.

While staring at the dash I noticed that the tach would go dead for a split second right when the TBI cut out. I checked the signal and power to the dissy and everything was 100%. Even gave it direct power to make sure it could pull the amps. Still nothing helped. So while at the parts store to get brake parts I picked up a cheapo stock module to see if that did anything. Guess what, IT FIXED IT!

Note to self, protect the dissy when welding/plasma'n the scout. ;)

Thanks goes to Bill and Mark for helping so readily. I learned a ton about what to look for and will keep this thread open to help give others ideas on troubleshooting.

Frankly, I'm not surprised it was something so small. I probably popped the module back when cutting the body off Rusty ~ I saw that because there was no battery in it after that point. I'm VERY pleased that the AFI system is such a trooper. It was super easy to install and from the word "go" it has run flaulessly. Thanks to Norm and Mark for such a plug-n-play system ~ I'm so stoked. I can't express how excited I am to get Rusty going and do some donuts.:evil: :D

Almost done!~

...I can't express how excited I am to get Rusty going and do some donuts.:evil: :D

Almost done!~
'bout time to sell it and start over again.:flipoff2:

Do you understand why the voltage check on B5 would have been the place to check?
If you lose the signal at B5 the injectors stop firing.

But you probably learned more by going the long way around.

Long way is right. I called a bad iginition module right off the bat. Should have listened to me instead:flipoff2:

Glad you got it running right.:smokin:
________
IntenseMature (http://camslivesexy.com/cam/IntenseMature)

'bout time to sell it and start over again.:flipoff2:
:evil:

Long way is right. I called a bad iginition module right off the bat. Should have listened to me instead:flipoff2:

Glad you got it running right.:smokin:
You're right, you called it right off the bat. I didn't listen because I knew the DUI worked great before ~ My bad.

Definately the long way. :shaking: Definately learn a bit.

I really appericiate your input Bill, you're half a world away and still just as much of this community as anyone.

My biggest point is the systems, even though they are different from points and a carb will try to tell you what is wrong.
It is just a different learning curve when working with electronics.

I really hate to see guys just poke and pray troubleshoot.

It cost a lot of time and money to just swap parts till you hit on the right one!!

In the middle of the trail.....maybe!!:D

Carbs and points have been around since cars began so it's what most guys learn.
The new Tuner generation really has it going on!!!!
Look at the power they are producing in a 4 cyl!!!

But sometimes technology can bite you!!!:evil:

Glad it's going.
I'll look forward to the upgrade to timing control!!!:grinpimp:

I have been around this engine deal for.....ahhh to many years

Here is a real good way to ballpark the timing, and it's easy. Get a vacuum gauge and plug into a port with FULL INTAKE VACUUM...none there? Tap into the brake booster if applicable.

Start er' up with the gauge installed and turn the distributer until the highest vacuun reading is reached, maintain RPM at or below 1,000.

Then back off the distributer 1" of vacuum lock it and your in the ballpark. Naturally, DRIVE IT and keep an ear out for the rattle of death.

I still have no logical explanation, but I had a 73 Ford F250 that ran like a sack with a timing light but came to life using this method. I had checked the damper/& pointer with a piston stop/degree wheel and the marks were dead on. After I set the timing using this way old method my initial was around 38 degrees, I still don't know!

For those who say they don't go to the other board....
A little more amplification on the system components.
Since I don't run a fuel only system Mark can confirm the placement of the tach filter on the AFI system.

But I may make a homemade one just using the AC-DC circuit in the 7 or 8 pin modules I have laying here!!
.....................................

Pictures are better than words....You will have to highlite the first one to see the connections on this dark board.

This is basically the ignition system you are using.
Pretty much the same as using the 4 pin module with the duraspark conversion.

Now on the neg side of the coil you also have the tach lead. You should have a wire that goes to the tach filter on your fuel only system.
The out put of that filter is fed to the B5 pin on the ECM to tell it the distr is producing a spark (actually a DRP-distr ref pulse) and this signal allows the ECM to start funtioning like fireing the injectors.

Now with your ignition breaking down...this signal would have been lost or would have decreased to an unuseable level....You would have seen this by taking the reading.

That would have left you with a 50/50 option of either a bad ign module or the tach filter.
which is more likely?
A simple check of the signal on the neg side of the coil (or your tach) would have comfirmed which it was.

Clear as mud now?

http://www.binderbulletin.org/photopost/data/532/1534hei_4_pin_wiring.gif

This is the pin out for the connections from the stock module to the ECM

http://www.binderbulletin.org/photopost/data/531/1534EST1.jpg

This is how the stock module works with the ECM and the distr and coil....

http://www.binderbulletin.org/photopost/data/532/15347_pin-gm-ign-module-schm-med.jpg

Since I don't run a fuel only system Mark can confirm the placement of the tach filter on the AFI system.]I've never run one always had the distributor. But they hook from the AFI harness to negative side of coil.

Glad your up and running Damian! By the way the same type module in EFI distributors seems to bring issues everywhere, ask Bill how many intermittent problems have been chased to it.

Bill your troubleshooting procedures are a huge help. Someday people will check B5 with a test light like the old school guys check negative side of coil for on, off, by the points with a test light.

Soryy to hi-jack this thread buttt.. I found it through searching and I need help from everyone involoved. I have a 69' 351w with AFI and DUI computer controlled. When I ran this as a fule only setup it ran great. When I switched to the DUI full comp controlled it back fired all the time at any timing level at any rpm over 1500. I have tried everything. Fuel pressure, new module, everything. Any hints on where to start? The only thing I have found that I did not check is the ground wire in the AFI harness that was labeled engine ground was not long enough to reach the computer when I got the harness and so I attached it to the block.I have done no welding on the rig at all when the ecm was hooked up. Norm and I are both stumped.Any thought?

I'll assume you locked the mechanical advance? If you've been dealing with Norm and he's stumpwd then thats bad. I would try yet another ignition module as I've gotten them bad right out of the box. Also, check the resistance of the pick-up in the distributor. I believe it should be @ 800 ohms resistance I could be wrong on this figure. Have you tried calling Performance Distributors who make the DUI distributor?
________
Live sex (http://livesexwebshows.com/)

If your distr looks like this, then it needs to have the 7 pin ignition module internal to work. The original fuel only filter would have to be removed from your original system and you would have probably had to add several wires for computer control. Not sure if Norm would have left all the wires in there if not being used...

http://www.performancedistributors.com/32820.jpg


Now if it looks like this one then you should have 2 leads coming out of the distr.
a purple/blk wire and an org/blk.

Make sure the purple goes to the P terminal of the EST(assuming that's what you are using)

http://www.performancedistributors.com/durasparks.jpg

More specifics on your system are needed.

If your distr looks like this, then it needs to have the 7 pin ignition module internal to work. The original fuel only filter would have to be removed from your original system and you would have probably had to add several wires for computer control. Not sure if Norm would have left all the wires in there if not being used...

http://www.performancedistributors.com/32820.jpg


Now if it looks like this one then you should have 2 leads coming out of the distr.
a purple/blk wire and an org/blk.

Make sure the purple goes to the P terminal of the EST(assuming that's what you are using)

http://www.performancedistributors.com/durasparks.jpg

More specifics on your system are needed.
I have the top distributor with the vacuum canister removed and a seven pin conversion. Norm made a four wire harness to wire the distributor to the computor.