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Discussion Starter #1
Hey guys, I seem to have some issues with my vettes tpi system. Just to weigh out the options, Im having some thoughts of doing a tpi to carb swap. Any of you guys who have done it, what do you do for the throttle cable, will the stock still work? What about the distributor, and finally, can I just regulate the efi fuel pump down to 6 psi or so, or is a new fuel pump gonna be in the equation. I have all but a fuel pump here in the shop to do this.

Thanx for the help in advance.
 

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Im having some thoughts of doing a tpi to carb swap.
Be prepared to have everyone tell you not to do it :smack
what do you do for the throttle cable, will the stock still work?
Stock early cable ( stud type) will work on carb

What about the distributor,
Any non computer controlled dist .Stock HEI with vac advance is easiest ( same hookup ) but can use remote coil type dist

, can I just regulate the efi fuel pump down to 6 psi or so,
Can use '84 CFI fuel pump ( direct swap ) and inline reg or a aftermarket bypass reg to drop EFI pump pressure down to suit carb.Most run new s/s braided lines up over bellhousing from the stock fuel filter and mount reg to firewall
Need to rewire pump relay to operate when key turned on
 

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As you don't state year or trans type ( essential info when asking questions)

You may also need
a temp switch in the head to control the coolant fan(s)
A corrector bracket for the carb to operate TV cable to auto trans properly and rewiring to operate the convertor lockup
 

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Discussion Starter #5
Well ya see guys, I got this car, an 87auto, 3.07, knowing it had some issues. The car was undergoing a MAF to SD swap and the PO, ran into some trouble and gave up. Now, hes done most of the work, its got a 730 ecm, a new sd harness, but said it would run but barely, seemed to miss, overfuel, etc. In looking at whats going on, I suspect it may have the wrong prom, or memcal- maybe even a v6 one thats causing this.

Im my research here, with vetteoz's help, we cant identify the prom because its missing the GM cover with the part # on it.

As Im finding out, the cost of the correct prom(memcal) new or used, is enough to cover the entire carb swap.

Thats why Im asking. Im not ready to give up on the tpi just yet, but weighing the options.

I will go work on my sig...
 

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Well ya see guys, I got this car, an 87auto, 3.07, knowing it had some issues. The car was undergoing a MAF to SD swap and the PO, ran into some trouble and gave up. Now, hes done most of the work, its got a 730 ecm, a new sd harness, but said it would run but barely, seemed to miss, overfuel, etc. In looking at whats going on, I suspect it may have the wrong prom, or memcal- maybe even a v6 one thats causing this.

Im my research here, with vetteoz's help, we cant identify the prom because its missing the GM cover with the part # on it.

As Im finding out, the cost of the correct prom(memcal) new or used, is enough to cover the entire carb swap.

Thats why Im asking. Im not ready to give up on the tpi just yet, but weighing the options.

I will go work on my sig...
Memcals are that expensive? Give hitechmotorsport a call. They might have something to help you. Ask for Brian.
 

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Well ya see guys, I got this car, an 87auto, 3.07, knowing it had some issues. The car was undergoing a MAF to SD swap and the PO, ran into some trouble and gave up. Now, hes done most of the work, its got a 730 ecm, a new sd harness, but said it would run but barely, seemed to miss, overfuel, etc. In looking at whats going on, I suspect it may have the wrong prom, or memcal- maybe even a v6 one thats causing this.

Im my research here, with vetteoz's help, we cant identify the prom because its missing the GM cover with the part # on it.

As Im finding out, the cost of the correct prom(memcal) new or used, is enough to cover the entire carb swap.

Thats why Im asking. Im not ready to give up on the tpi just yet, but weighing the options.

I will go work on my sig...
to verify what chipset you have-- it should be written on your chipset, not just the tag, acess door or on the plastic casing
Go to moates. net and set up an account. look under the downloads section and it should list out a variety of memcal numbers-- to verify what you have. You may just need to buy the ostrich option and do your own tuning.

Honestly this is going to be really hard to troubleshoot over the computer.


The 1986-1989 TPI cars used a MAF system ('165 series ECM), while the 1990-1992 TPI cars used a MAP system ('730 series ECM).
The pin outs are different and so is the internal coding. if those weren't changed properly then it won't run no matter what. or if they just pulled the memcal from the 87 and used it.. youd be stuck running in some limp mode.


if you really want to take this on here is a starting point for that hot mess you can verify your friends work.
http://www.cis.udel.edu/~davis/z28/ecm_swap_730/

or for $200 I have a haltech system you can have with all the instructions. It t has a faster computer similar to the 730 and doesn't need a memcal. Plus it's set up for MAP system. comes with it's own tuning program very simial to the holley system and I have an extra 1 bar MAP.
Pm me if interested.
 

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Discussion Starter #8
Ok, I may be interested in the haltech system. Secondly, the conversion appears to be done properly, its got the right ecm, a brand new SD harness(all labeled), the map sensor and all. Now, like Im trying to explain- Im not trying to troubleshoot the tpi here. Im just asking a few questions, about the carb swap( last resort) since I have everything to do that right here and for info on the memcals themselves.
As some of you may, or may not know, the blue cover has the gm part # on it, and Im missing that part. Ive seen all the links here and at 3rd gen, and still cant identify what I have. I have been to the site you suggested already. The moates one, I will check out. If, and thats a big IF, I could find one on ebay, they go around 2-300 bucks. Brand new from the general they are over 300.

Im just trying to do a little research, my guess is by the way the car "ran" theres a good chance the memcal is the problem- since everything else seems in order under the hood. That would explain the overfueling, missing, etc. Limp mode, I think you said.

Believe me, Id rather run the tpi and keep it near stock.

Thanks for the suggestions, I' ll have a look and be back !
 

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Discussion Starter #9
Ive had a look in the download area of the moates site and cannot find anything on any of the #s I have on this coverless memcal.

These are all the #s I have on it.

The base(brown part that plugs in) 68767 31101-1
The black chipset AT29C256
12PC
9523
The "jumper" looking piece on top next to the black chipset
1R1136

Thats all I have to go on...
 

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As some of you may, or may not know, the blue cover has the gm part # on it, and Im missing that part.
ID is printed on a silver label that is on the chip itself ; not the cover.Is visible through a hole in the cover.





Your is missing obviously; the numbers you quote are the chip part #'s which would / could be identical across a whole range of memcals because the individual tune is programmed on to those chips
Worst case you go to a aftermarket tuner like PCMforless and get a custom chip ( or stock tune ) burnt for $150
http://www.pcmforless.com/index.php?option=content&task=view&id=2&Itemid=43

They will even do you a factory stock tune of your choice with just the VATS removed for $100
http://www.pcmforless.com/index.php?option=com_content&task=view&id=128&Itemid=341

For $175 you could buy the Ostrich
http://www.moates.net/ostrich-20-the-new-breed-p-169.html?cPath=31

which allows you to load any stock or modified tune into your computer.Plus you can make any tuning adjustments yourself without paying for a custom tune
 

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Discussion Starter #11
Thanks VetteOz, thats what Im dealing with. Part #s for the chips are all I could come up with too. Now, I will look up the ostrich, what exactly does this do, and Id like to know more about this Haltech thing.
 

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Id liketo know more about this Haltech thing.
Still have to program it.
If you are sure your problem is the memcal then replacing that with a known working one should solve your problems.
Have you pulled the codes to see what is showing?
There may be other problems you don't know about that are putting ECM in limp home mode
 

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Hey guys, I seem to have some issues with my vettes tpi system. Just to weigh out the options, Im having some thoughts of doing a tpi to carb swap. Any of you guys who have done it, what do you do for the throttle cable, will the stock still work? What about the distributor, and finally, can I just regulate the efi fuel pump down to 6 psi or so, or is a new fuel pump gonna be in the equation. I have all but a fuel pump here in the shop to do this.

Thanx for the help in advance.

didnt you ask the same question under a "diffrent" corvette forum, Under the same "user name".

I find that weird, Polo

its seems like you started both threads the same day.

i belive those boys told you not to do that swap? It will make your car worthless, and you will be the laughing stock of your local vette meet.

don't do it

even if your car isn't running now, it will be worthless
 

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. Now, I will look up the ostrich, what exactly does this do,
Best tuning tool going.:thumbsup:

Using software you use a laptop to load a tune into the Ostrich which is connected to the ECM with a cable and adapter which take the place of the stock memcal.
The ECM reads the tune off the Ostrich unit and because you have access from a laptop you can change anything
you like in the tune; even while driving.
In the good ole days ; you had to remove memcal from ECM , erase it ( 15 min ) then burn a modified tune on it before reinstalling
Some guys did over 200 burns ( modifications to their tune ) to get their tune right; with the Ostrich you could make 200 changes in a day
 

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didnt you ask the same question under a "diffrent" corvette forum, the same "user name"
started both threads the same day. I find that weird,
Sort of the pot calling the kettle black
http://forums.corvetteforum.com/1576524132-post44.html

Many like to get opinions from different Forums

i belive those boys told you not to do that swap? It will make your car worthless,
Depends what is worth now not running

don't do it
Refer post #2

PS
You spelt Sidney wrong in your details
 

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Jeff didnt you ask the same question under a "diffrent" corvette forum, Under the same "user name". Started the same day?

I hope you get some anwsers

do you have the same password for both forums:smack
 

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Discussion Starter #17
Yes as a matter of fact I did wreckedvette.
I didnt think that was a problem...
 

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I don't see the problem of posting questions on other forums. Different opinions can help. Now stop with the thread jack.

As an FYI I made my Don't do it comment as a joke in reference to Vetteoz's statement in his post. This guy paid for the car and he can do what he damn well pleases with it.
 

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Discussion Starter #19
Thank you sir.

If I wanna drop a Big block chevy in it thats what I'll do. Im just fishing for all the info I can get. I got the car because of the TPI issues and in reality Id like to make it work- but, if I cant sort it out without spending alot of dough, I will carb it. At least then, I can drive it while sort out what needs attention.
 
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