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> Carb selection question, Bad day. MPS shot
DarrenG
post Aug 24 2008, 09:25 PM
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Bad day.

Took the teener ('74 2.0) for a test drive last night. first trip since the rebuild. Made it almost 3 miles. struggled to keep it from stalling, managed to get it up to 60, then total loss of power. Couldn't even get up a hill - towed home. She had all the signs of a blown MPS: extremely rich, hard to start.

This is getting old.

Options: Try to find a reasonable, decent MPS.
Switch to carbs - which I am seriously considering because I've had to fix broken wires on the harness 4 times already. When it has run (400 miles in a year) I had to constantly feather the pedal to keep it from losing power (another problem?). Just wondering how much this old FI system has left. I don't want to go too high end, because I'm upside down in this car already.

I am not trying to restart the carb vs. EFI debate. So, I'll stick with one specific question:

Are dual Weber 34 ICT's sufficient for a 2056?

This is a daily driver (hopefully), but I also don't want to get passed by some old lady in a miata.

Thanks for the advice.

D
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Todd Enlund
post Aug 24 2008, 09:31 PM
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I think they would be, but I think you'd be happier with a pair of 40 IDFs. A few extra $$, though.
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DarrenG
post Aug 24 2008, 09:48 PM
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$300 happier?

I know. tough question. I found the the 34 ICT's (NEW) for $350. About double for the 40's. better stated: would I notice much difference on a daily commute?

also: it does have the stock cam (new, but stock). I bought the car and cam before I found this or Jake's website.
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sww914
post Aug 24 2008, 09:52 PM
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For daily driving, you'll always be happier carbs that are with too small than you will with carbs that are too large. You'll get a few more HP out of 40's and with a 2056 they should run great, not too big, and it will run great with 34's also but you'll always know that you left a few HP on the table.
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SGB
post Aug 24 2008, 10:18 PM
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Oh the frustration!
I think it wold work fine, especially with the stock cm. It may seem kinda mild, but I bet it will rev up to the power zone pretty easily.
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SirAndy
post Aug 25 2008, 12:26 AM
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QUOTE(DarrenG @ Aug 24 2008, 07:25 PM) *

extremely rich, hard to start


CHT came lose or the wire is broken ...
(IMG:style_emoticons/default/shades.gif) Andy
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Dave_Darling
post Aug 25 2008, 01:36 AM
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Definitely a possibility. Check the MPS before you decide it's bad...

Sorry that I can't be of any help on the carb question.

--DD
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type47
post Aug 25 2008, 08:06 AM
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i would think it'd be cheaper/more cost effective/less work to fix the FI system than switch to carbs.
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DarrenG
post Aug 25 2008, 08:45 AM
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New CHT.

If it were just the mps, I'd bite the bullet. Cold start valve doesn't work and I have already repaired a bunch of wires - they are all brittle. I'm just not sure I could ever get this old FI system to be reliable.

Still not sure what I'll do.

Thanks to all.
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Joe Bob
post Aug 25 2008, 09:00 AM
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Doesn't Bowlsby have rebuilt MPS modules?
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rhodyguy
post Aug 25 2008, 09:10 AM
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greg robbins has a set of pro-rebuilt italian 40 webers for sale right now in the classiffieds. if you're going to switch, that's as good a price you're going to find and they will work nicely with your 2056. they will out perform the 34 icts. if they have the 28mm venturis the high top end will prob suffer a bit but you'll get good port velocity down low and in the mid-range. look for a set of NEW cbperformance tall manifolds and maybe mallory dist.

k
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Joe Ricard
post Aug 25 2008, 09:30 AM
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If I didn't already have carbs I would choose EFI.

Way more streetable

better economy

if you ever lived through a session of plugged idle jets you will kick yourself for EVER going carbs

Just cut the harness open and replace the entire wire.
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Bleyseng
post Aug 25 2008, 09:40 AM
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Send the FI harness to Jeff Bowlsby to fix or rebuild. Its easy for him to fix and worth every penny for a DD to have good electrical flow. MPS's are around and FI is nice for a DD.

I get over 30 mpg on the highway with mine...city mpg is less cuz I have a lead foot.
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BarberDave
post Aug 25 2008, 10:57 AM
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(IMG:style_emoticons/default/smilie_pokal.gif)

PLEASE,- PLEASE don,t go with the single barrel 34 ict webers. I have had on

my 73, 1.7 , Single Carb, often refered as a Boat Archor, 34 ict Webers, and

40IDF Webers. First 2 ran like SHIT. Had all kinds of problems with driveabilty.

34 ITC's remember I had a 1.7 yours is a 2056.

What is wrong with them ?????

Well lets start a low speed, ( these were fresh rebuild) Up to 35 mph it ran so

bad , in order to cross a intersection you better have 2 blocks clearence, or really

over rev. the engine and slip the clutch, ( that is good for a long life).

High speed:

Above 60 MPH it wouldn't get out of it's own way. Above that NO

excelleration, if you were on a limited access highway you stay in your own lane.

Just don't try to pass that one car we all run into that drives 55 in a 70 mph zone

it will take you 2 to 3 miles to do it.
I think they are dangerous, on a 1.7 Let alone a 2056!!!!!!! My 2 Cents

Now for the good, mileage the highest highway i got was 39 mpg

Please you would be in danger with the 34's.!!!!!!!!

40idf's run great , mileage in the low 30's IMO difference

is not worth the risk. If you race then 44 IDF'S may be the right choice.

Dave (IMG:style_emoticons/default/slap.gif)

EDIT, Or Rebuild the F.I.
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JeffBowlsby
post Aug 25 2008, 02:17 PM
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QUOTE(type47 @ Aug 25 2008, 07:06 AM) *

i would think it'd be cheaper/more cost effective/less work to fix the FI system than switch to carbs.


(IMG:style_emoticons/default/agree.gif)

Its much simpler and less expensive to just fix the problem rather than replace systems, and create new problems. D-Jet is not hard to diagnose and fix, rebuilt MPSs are available for ~200 last I checked. See Performance Products.
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Gene
post Aug 26 2008, 12:04 AM
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I'm going the route of just building my own megasquirt 2 system. No more vacuum issues and then I'll time it with the Ford Edis system. Under a grand total and I can fix every bit of it quickly. I prefer circuits to mechanical things like vacuum and points. For the money you'd spend on carbs you could buy the premade megasquirt 2 system and throw on an electronic distributor (crane optical/pertronix 2, etc) and have pretty much the same fuel injection attributes you get with the stock system when it's working and much less wear/possible failures.
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DBCooper
post Aug 26 2008, 07:29 AM
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Unless you're already well versed in tuning and syncing multiple carburetors the best advice is to fix your stock FI. Both cheaper and better. Test the MPS, get a rebuilt one if you need it (you may not). Get a new harness made and you're done for another 30 years.
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DarrenG
post Aug 26 2008, 07:50 AM
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ok, I'm convinced. I'll get another mps and have the wiring harness fixed over the winter.

thanks to all.

D
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