My sensor is dead, so i thought i would just spend $40 bucks and get a new one...ha! was i wrong...so my mechanic buddy (i'm stoopid) recommended to convert to carbs.

I'm just doing a single carb set since i got a $400.00 budget.

I can't believe that sensor is $800 to $1200.....

anyway do any of you sell or know of a good deal? I found this on ebay which is just in my range..

what do you think?

http://cgi.ebay.com/progressive-weber-carb...1QQcmdZViewItem

Nooooooo! Don't do it!

You would be better off finding a rebuilt sensor Bleyseng repairs them.

IMHO that carb is the worst thing you could do to your car

i prefer carbs,but a single carb really is not the way to go.
since you allready have fi.keep it.a true carb conversion is not cheap.(cam,DUAL carbs,ect.ect)i have boxes of fi systems.(2.0/1.8/and 1.7)send me a pm of the part you need.ill sell it to ya cheap.(used of course)or talk to
Bleyseng he can fix ya up with a rebuilt one.if its the part i think you need.
james

Specifically, that SINGLE carb is the worst thing you could do. Dual Webers can work, but a complete used setup will run you $500 or so. Fuel mileage will plummet with an otherwise stock engine (18-22mpg, typical).

There are used MPS sensors out there, and some of them even work. You can also explore aftermarket EFI, which ditches the MPS for a modern sensor ($400-1200, depending on what you get and how much you can do yourself).

QUOTE (fatlando @ Jul 30 2005, 08:03 PM)

what do you think?

don't forget the dist!! and tuning them is not fot the faint of heart!!!( dual webbers) that is!!!!

Don't give up on the FI. In my experience a good running FI car is far superior to a good running dual carb car. A single carb is a big step backwards.

Get a new mechanic, and a new friend. Obviously he is offering a cheaper alternative to what I gather is an MPS?? Converting to carbs is going to cost you over half of that budget, and a pain in the ass getting it dialed in (add to that cost). You can find used parts that will work fine, if Bleyseng is rebuilding the units - do that.

You can find a good used MPS for not a lot of money (comparatively speaking) - stay away from ebay on those units - just be sure you can test the unit with a vacuum guage and return it if it is bad.

my mechanic managed to find a rebuilt FPS for less than $200...PM if you want any info..i'll check w/ my mechanic.

QUOTE (dlo914 @ Jul 30 2005, 06:10 PM)

my mechanic managed to find a rebuilt FPS for less than $200...PM if you want any info..i'll check w/ my mechanic.

correction it wasn't the MPS, it was the Fuel Pressure Regulator...sorry

FPR's are available from all the porsche parts houses for under 75$

QUOTE (echocanyons @ Jul 30 2005, 06:36 PM)

FPR's are available from all the porsche parts houses for under 75$

yea he got mines for $70

QUOTE (fatlando @ Jul 30 2005, 05:03 PM)

what do you think?

"This is a great way to add power"

QUOTE (Travis Neff @ Jul 30 2005, 06:53 PM)

Get a new mechanic, and a new friend.

wtb,wtb,wtb. the classifieds man. in addition to carbs and dist add in a GOOD linkage, and a new fuel pump. don't do the single, esp for $400. does anyone know if it matters if one is off a 1.7/2.0 djet or a l-jet? lando, did you ever recieve my message about the steam cleaner? i never heard back.

k

Fats: I'm curently doing a conversion on a 1.7 to twin Solex 40's. I have done a conversion on my 1.8 that is my daily driver. I'm completly happy with it and would recomend it to anyone needing to use thier 1.8 914....
:PERMAGRIN: Joe

if you continue to follow this thread, you WILL get varied opinions on this topic. But most carb fans will agree, the single progressive is bad.

Most carb fans will also tell you, that without a "carb friendly" cam, converting is REALLY bad....not a simple as pulling off the FI then bolting on carbs.

good luck

So i'm sitting on the fence with no real strong opinion one way or the other about carbs VS FI. I have a stock FI system that ,for now, works great. I have driven carbed cars that ran like crap for whatever reason. So I think this is a preference question. What I am questioning is why the single progressive carb is a "bad" idea for a stock engine?? It worked for VW for a lot of years. I used to have a beetle with big bore kit, ported heads, cam and a single two barrel. Seemed to run really good. So whats the technical evaluation of why lando shouldn't do the single carb conversion?

Do a Subby or Cheby V8 and be done with it.

i'm still confused as to which fi component is bad. shane (red914) dumped the progressive and went to the dual single barrel set up (pretty cheaply iirc). seemed to help with the running of the beast.

k

QUOTE (Michael J @ Jul 31 2005, 12:15 PM)

So i'm sitting on the fence with no real strong opinion one way or the other about carbs VS FI. It worked for VW for a lot of years. I used to have a beetle ...

i installed a pair of SMALL dellortos on a 1,7 with SMALL venturiis. IMO it had no more or less power than the FI, it started and ran every day (unlike the FI) and had no better or worse mileage than the FI (except when the FI delivered 4 weeks per tank because the car was PARKED.)

but that was in 1980. no Internet resources, no online parts vendors. i PROBABLY wouldn't make the same choice today.

carbs are DEFINITELY a place where bigger is NOT better.

the single carb worked OK on a beetle because it was DESIGNED to. even so - no performace cars used it. the carb was a SINGLE barrel, and thus had pretty constant airflow through the venturi. it had (IMPORTANT!) a manifold heat riser that kept the mixture atomised on its way to the intake ports. it was HIGH which helped minimise the amount the air/fuel charge had to change direction.

low, no manifold heat, big plenum runners, progressive multi-barrel just can't work right on a little engine.

if you could find a set of 40mm Dells and run little venturiis you'd probably have a good solid system once you got it jetted right and synchronised. no amount of glowing ad copy will ever make a single progressive run right on the street. (you can imagine a scenario where they might run with ok power numbers at WOT on a dyno. but i need my car to perform on the street.)

Hey all this is Landos' Mechanic friend who by the way someone recommended "find a new mechanic friend"

I have done the research and have come up with this...

- FI is better at producing power/gas mileage and supposedly engine longevity due to carb setups not heating up the heads properly.

- Conversion to a carbed setup is a big no-no among 914 owners.

- If converting to carbs duals are better at producing power but not as good as a FI setup.

The reason a carb conversion was suggested was this...

- while trouble shooting an idle seeking problem...once started car idle goes up and down very consistently...MPS sensor was found to be bad (will not hold vacuum at all, doesnt slowly leak down, completely leaks by) initial research showed them to be quite pricey.

Based upon the price of a new sensor a single carb setup was suggested as it would have the car up and running for significantly less $$

I would love to keep the FI setup for him so let me give you guys some info on what i have found.


- Engine has been desmogged.
- 1 Air injector port is missing and there is just a hole there (what would you recommend plugging the hole with) could that cause the idle issue.
- Crankcase was overfilled with oil along with various vacuum lines mis routed resulting in oil getting sucked into other vacuum lines.
- MPS sensor is bad (would that cause the idle seeking) where can they had cheap?


If someone has a picture/diagram of a Desmogged 75 2.0 I could verify all his vaccum lines and make sure they are all correct.

Thanks guys, I aint trying to randomly trash a FI system but I am trying to help a friend get his pride and joy running again with a limited budget.

QUOTE (bing101 @ Jul 31 2005, 10:06 AM)

Thanks guys, I aint trying to randomly trash a FI system but I am trying to help a friend get his pride and joy running again with a limited budget.

This can be fixed for much less than going to carbs. Somebody here has a really nice diagram, I'm sure they'll post it soon. The MPS can be had used and tested for under $100. Just to get it running it'd probably run on a bus MPS.

Also, somebody recently bought a bunch of odd sized bolts or something for plugging smog ports from mcmaster carr, I think they still have a bunch left.

Ok, so we're talking PNW guys here. Kevin, Al, Geoff, help these guys out and get the car running right. I bet Geoff knows all there is to know about a '75 engine.

[QUOTE]it had (IMPORTANT!) a manifold heat riser that kept the mixture atomised on its way to the intake ports.

Thanks Rich, after a few cups of coffee this made all kinds of sense.

That was me who dissed you. I said after that, I also said that obviously you are trying to find him a cost effective alternative to a brand spankin new MPS.

A single carb is a helluva compromise. Dual carbs, and toss in a carb cam it can be great. All I am saying is that for not a lot of money that MPS can be replaced with a good used one.

The cost of the carb, manifold, fuel pump, pressure regulator, distributor (if you are swapping) plus the time to install and tune - that can add up to a lot of money. Plus I haven't heard very many people with a single progressive carb say that they are satisfied with the all over performance, most of them say it sucks.

If there is a ton of stuff wrong with the FI, I can see the justification, but all that was said was that there was a bad MPS, time for a carb. To me that sounds like a bad descision.

hi, i've sent lando a pm this am. his engine is a 1.7 correct? my take on carbs (40's). a used set will run 300 to 400. may or may not need to be rebuilt. may or may not include intake manifolds, add 35 to 50, used. linkage, prob not included, 85 to 240 new, (you get what you pay for). an 009 for an inexspensive dist. i have a good one that can be had for next to nothing (lando can mow my lawn ). fuel pump, buy a new self regulated, low pressure rotary from cb perfomance. the facet style makes a hell of a racket and you will need an adj fuel pressure reg and a gauge to varify the fp, more money. mho, the 2 barrel progressive is not the way to go, a used one is ntwtgx2. it adds up quick. this does not include the various jets and what not that will surely be required. btw i run 40's on my 73' 2.0 so i know what the play is.

that being said, there was a recent thread that was very interesting. it discussed the mating of l-jet compoments and d-jet items. a good, tested mps will run 150 to 200, and some sort of perfomance garrantee should be expected. pehaps less $. if lando hasn't pointed it out, the vaccum line diagram @ pelican in the 914 tech articles will detail every hose, size, length, and routing. line sources, williams oil filter service in tacoma (oh, TACOMA!!!)(cheapest source for high pressure fuel line and the correct clamps that i have found )should have what he needs, or small car performance, ovals, or too quick's out near me.

don't be too offended by the "get a new mechanic" line. we see many plans by folks, with bad suggestions from people less experienced with our stupid cars, and are pretty quick to correct in a less than polite manner. mostly because it gets people's attention. eventually, we are all forced to throw some money at these cars, we just don't want to see lando thow it in the wrong dirrection.

k

plus... i may be totally off base. my guess is the air injection port needs to be plugged asap. personally, i would fix that before i did any vaccum leak chasing. the oil leak issue... the bottom of the car needs to be STEAM CLEANED. MONEY WELL SPENT!! i explained why and where to lando, and made a suggestion via pm. tracing down the leak will be MUCH easier. on top of the heat exchangers? guess-valve cover gaskets or oil return tube seals. on top of the oil filter, guess-oil cooler seals or a leaking oil pressure sender/switch.

k

it seems that folks seem to prefer Dell over Webers....

why is that if you don't mind?

end hijack........

me? the totaled car i bought with an engine that has taken me to cal twice and lots of local driving, came with a set of webers.

k

Yes I agree that air injector port needs to be plugged ASAP. I will pm him and see if he still has any of those bolts left.

Regarding the oil leak, I dont think he has a true oil leak, it was due to the engine being overfilled with oil and that issue has been resolved

A rework of the FI system including new Vacuum hoses and possibly new seals where vacuum can be lost (fuel injector seals, throttle body seal, intake manifold seals, etc) will be my path to fix this FI setup.

Also does anyone have a source for those MPS sensors and a price. Its a 75 2.0

Thanks for the help guys.

bing what? crosby? what's your real name. geoff (bleyseng) had one fs. tested i believe. maybe still in the classifieds. pm sent.

kevin

source

Um... Out of curiosity....

What kind of carb does that single carb take?

Because if its a holley carb... then you can easily convert a "single carb" setup to a computer adjustable holley efi setup....

Any comments?

QUOTE (Andyrew @ Jul 31 2005, 04:33 PM)

...you can easily convert a "single carb" setup to a computer adjustable holley efi setup.... Any comments?

you mean a TBI system?

you still have the issue of big, long runners and multiple changes of direction.

flat engines need port injection.

QUOTE (Andyrew @ Jul 31 2005, 01:33 PM)

Um... Out of curiosity.... What kind of carb does that single carb take? Because if its a holley carb... then you can easily convert a "single carb" setup to a computer adjustable holley efi setup.... Any comments?

I have a Holley TBI injection setup on my Mustang.. it sucks donkey balls. Big rich spot just off idle that makes it bog. It won't tune out no matter what I do.

They're also made for V8s and probably wouldn't even tune down to type IV fuel flow rates.

I believe the single carb is a holley progressive (but what do I know), if you could put the injectors above the intake valves (as stock) that may be a decent alternative.

QUOTE (Andyrew @ Jul 31 2005, 01:33 PM)

Um... Out of curiosity.... What kind of carb does that single carb take? Because if its a holley carb... then you can easily convert a "single carb" setup to a computer adjustable holley efi setup.... Any comments?

the single carb used is basicly a 2 barrel carb, the reason it's not the best for these engines is that the carb is too far from the intake valves, the air/fuel mixture bounces along the long intake tubes, what happens is that everytime this happens, some of the fuel will now turn from a vapor to a liquid and "stick" to the intake tubes and now you'll have a strange and incomplete air/fuel ratio....2 progressive carbs closer to the intake valves would be better.

I've seen the single carb setups on eBay for less than $300, what you could do is get the car running with the less than ideal single, save up your money and once you have about $1200 or so, use the remaining stock FI parts and install a modern programable FI system.

QUOTE

once started car idle goes up and down very consistently

Is it hunting pretty quickly? If so, that doesn't sound like MPS to me. Sounds like vacuum leak at AAR or along that path between air box and cold start valve.

Listen to these people, they're giving you all the right answers.

IMHO, find a rebuilt MPS. In the long run it will end up being the cheapest answer, even if it doesn't seem like it.

if you have an open air injection port...... you will know. trust me, makes a hell of a racket.

you can find bolts to plug those holes at a decent hardware store. do a search here, there's a good thread by mueller iirc.


also, it's amazing to me that a bad mps will often still run an engine. if your mps doesn't hold vacuum at all, than of course it should be replaced -- but it does sound like you've got a variety of problems. 75 2.0 requires an 043 mps, but any of 'em can be recalibrated to spec that spec.

Update :

Air injector port was sealed with a bolt and we commenced finding that vacuum leak.

After some trouble shooting looking for a vacuum leak with carb cleaner, we found a gasket was missing tween the intake manifold/throttle body.

No other leaks were found yet so we are gonna replace that gasket (on order already)

Also fuel pressure was checked and fuel filter swapped (already had spare on hand)

Someone asked if the idle seeking was fast or slow i would say 1.5-2 seconds low then the same high and back to low, very rythmic.

also when gas is applied, it still does the same thing although with a little delay.

it definitely will not hold a steady idle

Sounds like you are on the right path to finding the vacuum leak, may not be the pressure sensor after all. The symptoms you describe are classic for vacuum leaks. Maybe there is a crack in the plenum, leaky hoses or bad gaskets. Good luck!

Ususally its all three plus bad injector seals....

well we do have a "loaner" mps and our is definitely bad (holds absolutely NO vacuum) but there are a couple other probs as well.

As far as injector seals we checked em and they didnt indicate a leak with carb cleaner but we will investigate that further once we replace the TB gasket.

Thanks for the help guys

bing101, where is Washington State are you?? Could you narrow it down for us?

Don't tell me you live near Kevin........

If you are in Seattle I can take a look at it.

QUOTE (Bleyseng @ Aug 4 2005, 08:47 PM)

bing101, where is Washington State are you?? Could you narrow it down for us? Don't tell me you live near Kevin........ If you are in Seattle I can take a look at it.

bleysing,

we are in the cool little town of Bremerton!! 45 minutes from rhodyguy and 25 minutes from DN Hunt. Dino lives here too!!!!

I will be down there in Sept for the AX so maybe then....

I thought that gasket was NLA. I know I made my last one.

Dave