MLS Install

MLS

MLS

Member
I got my TBI running the other weekend and have been fixing all the bugs since. Today I took it for a spin around the block and it won't rev over about 1500 rpm while in drive. Revs just fine up to 4000 while in park. I have an aldl cable, just waiting for the computer download. Any suggestions?

Sorry I missed the last wheeling trip, just couldn't get it done in time.
 
Re: TBI wont build pressure.

Have you done the voltage checks?
What are the inlet and return pressures?
When you rev it up?

What's your timing set at with the bypass open and connected?
 
Re: TBI wont build pressure.

I am not getting voltage from e7 (esc signal) everything else has power. Next, I did have my fuel pump wired the wrong way and when running through all this stuff I wired it right, but now there's no power out from b2 (fuel pump signal) and the pump doesn't come on. Suggestions? I have another esc I'm going to try right now. Thanks, and sorry for high jacking the thread so far dboy.
 
Re: TBI wont build pressure.

Follow the attached when doing voltage checks. B2 is only powered for 2 sec when the key is turned on then when running.
 

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  • voltagechecks.xls
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Re: TBI wont build pressure.

I keep that voltage test sheet and this wiring diagram in the glove box just in case. You need to go to kinkos and have them print it on the 11x17 paper in color to read the fine print.
Or blow it up to 200% on you p.c. The other thing I keep in there is the inital system setup doc bill created too.
 

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  • Colored wiring diagram.pdf
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Re: TBI wont build pressure.

I haven't done the initial set-up procedures before I started screwing around with getting it running. So before I make any more fubar's I'm gonna do them and log some data. But I'm still having trouble with getting my fuel pump relay to work. I followed the diagram for the stock relay circuit and nothing. When I turn the key on (b2) does not send any volts, not even the 2 seconds. Also, no volts during "key on" for b7 the esc signal? Thanks
 
Re: TBI wont build pressure.

I recommend you check each wire from end to end and if the voltage checks still aren't good then you need to start thinking about what you burned up by having it wired wrong to begin with.
 
Re: TBI wont build pressure.

Voltage checks are done and all good now after replacing ECM and icm. Fuel pressure is a steady 12 psi at idle and at full throttle. I still have to hook up the aldl to my computer but have been having issues with the usb to serial port cable I got. Thanks for the help, for some reason even when I'm logged in to the forum it won't allow me to open up some links you guys post up??
 
Re: TBI wont build pressure.

Making progress!

Keep in mind that I have most things duplicated on the main IH sites.
The binderplanet has the most data layed out with FAQ's.
From step by step to the data logging and basic tuning.
No reason I know of that the links don't work here.
 
Re: TBI wont build pressure.

Just for shits and giggles I logged this today. Still have a lot to learn so be nice!
 

Attachments

  • 20100512_182809_LOG.zip
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Re: TBI wont build pressure.

The log doesn't look that bad but where is the blm log?

I'm also confused, what system is this supposed to be and what engine is it on?

Bcc code on chip/ECM?
 

Attachments

  • 20100512_182809_LOG.xls
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Re: TBI wont build pressure.

ECM is a 7747, wiring is from a 92 Chevy 1500, sensors are all from donor or jy, currently on a 345. Went to log the blm data and start a aldl bin file to post but now can't get the Scout to start! Has fuel, spark, and my volt checks are still good. I'm a little stumped, have to do some more searching. I'll post up again when I figure this out. Thanks
 
Re: TBI wont build pressure.

What's the 4 letter code on the chip? And the box.

Something like aksf.

From what I'm seeing it looks like a 4.3 chip in that thing.
 
Re: TBI wont build pressure.

Ok one post said awhc which is not a 7747 but a 5.0 6299 ECM.
The post now says aksf which is a 7747 but for a 4.3.
So either way the parts don't match the install.
 
Re: TBI wont build pressure.

The ECM I originally got with the harness was a 6299, I switched out to the 7747 when I could not get the fuel pump or est to work. What now? Also, I still can't get the truck to start. Volts are all good, I have fuel and spark?? Double checked my timing and reluctor phasing. Weirdest part is the truck ran great the night I posted that last data, then the next night won't start at all???
 
Re: TBI wont build pressure.

Did you verify the pinouts between the 2 ecms to make sure they were the same? If voltage checks are good I assume they are. Both are c3 ecms but they did change wiring on occasion.

With a v6 chip the fueling is not going to be right. I would pour a little gas in the top and then hold the pedal down (clear flood mode) and see if it starts. If not then pull a plug and see what they look like.

But you need to swap out both chips in the ECM or swap to a v8 ECM.
 
Re: TBI wont build pressure.

Bill, can I swap chips from the 6299 into the 7747? I'm getting frustrated with it deciding when it wants to run. Went out this morning after I posted and it fired up just fine. I took it for a quick drive. Then settled in to adjust the idle and some other things, I had to shut it off to deal with new puppy issues. Now it won't start again. Aargh!
 
Re: TBI wont build pressure.

I tried pouring a little gas in the tb, nothing. Pulled #8 plug, black and covered in gas. Thinking my coil is bad, I just swapped in a new icm. What else could it be?
 
Re: TBI wont build pressure.

mls said:
I tried pouring a little gas in the tb, nothing. Pulled #8 plug, black and covered in gas. Thinking my coil is bad, I just swapped in a new icm. What else could it be?
Click to expand...

It's what I posted above. You are trying to run a v8 with a v6 ECM.
You can not try to adjust and tweak to make it ok. It needs to be set up right. The chips do not swap.

The ECM see 1 rpm as 6 cylinders. You are firing 8 in each rpm. So the fuel delivery and timing will not be right. Yes you May be able to get it to start and run and May even drive it, but it will never be right or really even close.
 
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