MY TBI INSTALL

[MPGmustang]

the ECM is off my 'fuse' box, connected to starter solenoid connected to battery, the alt is connected at the solenoid. it should see 'full' power all the time. but is does see voltage drop at idle. 12.1v to 14.1v is the full range I'm working with but mostly 13.1 to 14.1. it could also be the battery, mustang battery 'died' so I am using my older bronco battery... I'll recharge the other and see if that has any affect.

thanks Robert, as far as 'learning' no, none, it's very consistant, but on adjusting it's awesome, places/times where my carb would stall the ECM keep the engine running and it's VERY nice. SUCH A RELIEF!!! some cool things to know... city mpg is 17.5 with bad/high warm-up idle (2700rpm) and 23mpg freeway with poor high speed acceleration. I'm sure these will be imporved but they are the same as my 2bbl carb according to my records. t-stat temp ~210-230 and I NEVER ping (heat will help mpg, but I previously saw water temp from rear of head). so the ECM has some very nice benefits. absoutely worth it, and it's just going to get better.

 

[MustangSix]

What vacuum port are you using for the MAP sensor? If you have inadvertently hooked it to the ported vac, it won't idle correctly and the transition off idle will be flaky.

Also, not sure I understood one of your earlier posts, but your idle vacuum should be high and drop under load. If you have a stock cam, you should have 19-20" manifold vacuum at idle. 5-6" is a pretty full load with a stock cam. 2-3" should be where you are at WOT. If you have a 300 degree cam with a real lumpy idle and only 5-6" vacuum at idle, you need to convert the system from speed density to an Alpha-N strategy to use speed and TPS for load calculations. It will never work right in a speed density mode.

How's the fuel pressure?

For software, you can download http://www.tunerpro.net/. You should be able to use a $42 definition mask with the ECU you have now. You can download that file from Moates.net or thirdgen.org. Keep in mind though, that while you'll be able to datalog and read the current chip, you won't be able to write to that chip since it's not a flash eeprom. Moates makes a device called the Ostrich that has a flash eeprom replacement for that chip that you can reprogram on the fly.

Best bet would be to check for vacuum leaks, MAP connection (no leaks), and fuel pressure. Then datalog using tuner pro to see where the Block Learn Mode (BLM) numbers land.

 

[MPGmustang]

the map sensor is on full ported vacuum, checked it with a vacuum gage.

15 inches is the MAX I can make with my 265/274 cam, idle it makes 5-6 vacuum. I have 0 inches at WOT, as it's a 2bbl GM TBI it's MUCH larger than my old 350cfm holley, I don't have a speed signal, mabye an engine speed signal as it does control the spark.

I didn't make the system, I bought a kit and AFI (Affordable Fuel Injection) will 'tune' it for daily driving.

it does idle at 850rpm, only after it warms up, and when it gets there it takes its sweet time to get that low. only when I turn the car on when cold does the 'warm up idle' reach 2500rpm also known as 'choke' for a carb. granted that's not the same but it's the 'time' period that the engine is warming up.

I don't know about the fuel presure it's not to be more than 15psi as it's a low presure GM setup.

 

[bubba22349]

X2 WOT reading 0 vac is a sign that the TBI may have to much flow, for best throdle response you need to aim for min. Of 1.5 at WOT.

 

[MPGmustang]

okay, I don't understand, why in the world do I want vacuum at WOT?

with a carb I might be able to understand as you don't want a lean mixture, but with a TBI that's controlling mixture on the fly I'm getting as much air as I can and the fuel ratio will be perfect...

so, why the heck would I want vacuum at WOT?

 

[MustangSix]

First things first.

1. Speed Density has nothing to do with speed sensors. It's a fuel injection strategy that determines fueling based on load (vacuum) and RPM. Fueling will vary according to temperature and throttle opening rate (accelerator pump enrichment). If you have a very high overlap cam that cannot develop adequate vacuum, you need a system that can calculate fueling based on other factors. Alpha-N is the strategy that uses throttle position (via the TPS) and RPM as the primary measures of how much fuel is needed.

2. I think that with your cam, vacuum should be higher than that at idle. 5-6 inches sounds awfully low. Again, what port are you measuring that from? If that's what the MAP is seeing, it's no wonder the car has a bad off idle transition. There are three ports on a GM TB. One is ported and opens above the blades at idle. It will not give you a true engine vacuum reading at idle. Actually, it would be best if the MAP were plugged directly into the manifold.

3. Vacuum at WOT is determined by how much restriction is in the intake system when the engine is a full load. Some engines can ingest more air than the throttle body can deliver, hence a vacuum. That may not be the case with your system since the TB is fairly large and a log head is fairly inefficient. If you see some vacuum at WOT it means you might be able to use a bigger TB to flow more air. With port EFI, 0" vacuum is ok; the fuel map can flow whatever it is programmed to do. With a carb, you need some pressure drop or velocity to enable fuel flow. With TBI, it's kind of a hybrid. The TB will deliver whatever the fuel map is programmed for that RPM, load, and temp, but at 0" vac, fuel vaporization on the manifold floor might be a problem when the engine is cold.

4. Datalog. It will tell you a lot.

 

[MPGmustang]

1) I don't do any tuning... yet... I THINK it is doing the alpha-n method
it has
TPS
Ignition (7 pin DUI so it controls timing and knows the RPM)
MAP
IAC
water temp sensor
narrow band O2 sensor...
AC high idle wire

2) this cam HAS ALWAYS ran this vacuum on idle, although I do think I have a vacuum leak. in all honesty I think it's been the most it's ever been on idle, it's really around 7-8 vacuum. CI says this cam will have 15 vacuum MAX, it does in the higher RPM's, and yes I have been thinking about swapping it out with something around 260* non-CSC like an isky, or comp, but that's not yet.

3) so NO WOT at cold temps... I understand what you are saying, the TBI is a hybrid, so it will have both symptoms in a way, when I floor it ATM it 'waits' then slowly it 'goes' and then it accel's. I'm not really driving it much due to needing spindles, and a new tune, and possibly a vacuum leak.

4) I have data logs, alot of them, don't know how to read them... I've sent them to AFI and they have a new chip coming to me, should be here on 9-13

5) I'm almost positive I have a vacuum leak... I took everything apart.


The putty is separating, I've talked to mike and he'll fix me up, but in the mean time I got nothing... I won't be able to drive like this for ever.
FOR NOW, until I can take the time to fix it, I'm taking the ultra copper RTV silicon gasket maker, and apply'n it all over the area, hoping it seals it long enough for me to have time to take the head off to get it fixed. I have one layer on right now, I'll do more layers, but the one moved the idle from 1300rpm to 1050rpm, so there is a possibliliy this 'patch' can work temporarily. I'm not drving it right now, but it's raining and here it would rust in a day if I took the head off outside so I'll have to wait for a garage.

all this and the wedding coming up... I'm very stressed.






(I have asked about the O2 wide band system, they have it but it won't be 'tie(d) into the ECM' so I do have a narrow band, it's works so nothing too bad about it)

 

[MustangSix]

I'd still bet you have a major vacuum leak that you haven't caught yet . Your idle vac is just way too low for that cam, but seeing it rise tells me you have a leak. It really should be 14-16", I think. Those kinds of MAP readings are going to confuse the ECM. It thinks the engine is under full load at 1000rpm and is trying to manage timing and fuel to keep it running.

 

[MustangSix]

I'd still bet you have a major vacuum leak that you haven't caught yet . Your idle vac is just way too low for that cam, but seeing it rise tells me you have a leak. It really should be 14-16", I think. Those kinds of MAP readings are going to confuse the ECM. It thinks the engine is under full load at 1000rpm and is trying to manage timing and fuel to keep it running.

 

[MPGmustang]

I don't mean to be agressive or offensive or defensive, but it just doesn't work higher unless more RPM. even with my 1bbl on this head before 2bbl modification, when vacuum was impossible to leak. it was the same vacuum.

V8's with aggressive cams and loopy idles have low vacuum, this is an aggressive cam, my overlap is 49*, that's 21* more than stock (and stock is 28* so it's almost double stock overlap!). this won't get full vacuum. if the overlap was lower around 35-40* maybe I'll get full vacuum at idle. but this one is too aggressive!

to fix the vacuum at idle I need a less aggressive cam... that's the ONLY way to get the vacuum higher at idle, unless I use a vacuum pump.


EDIT:
sorry I don't mean to come off loosing my cool and I really appreciate the help you have been freely giving, I understand that the cam vacuum affects idle and especially the TBI system, they have tuned it around my specs, IDK if it's 'perfect' but I'm going for usability. and I know my cam isn't 'usable' as I'd like it. and I know I want to change the cam, I just don't want to tear apart the engine right now... I understand that it might be holding me back. but I do have quite a bit to fix and too much to stress about and it's getting to me...

on the intake vacuum leak Elmo, the CI head builder, said to use JBweld to seal it back up. it sounds like it will work, but I'm going to continue using globs of RTV ultra copper, I have a fear of the JBweld becoming loose and going though the engine and messing something up. this way I'll have RTV and it won't kill the engine.

 

[69.5Mav]

it's really around 7-8 vacuum. CI says this cam will have 15 vacuum MAX

A couple of things to consider.

At your altitude you will naturaly get a lower vacuun reading, about 1 less. When I lived in Sierra Vista AZ I got 5 less.

You could be suffering from a combination of things.

1. Late valve timing. See senario 10 of this website http://www.secondchancegarage.com/public/186.cfm.

2. A small vacuum leak.

3. An agressive cam.

These could all combine to give you a 7-8 vacuum reading.

I understand your busy , did you say wedding?, so feel free to use my guesses for what ever you want.

Good luck. I'll be watching your progress with interrest.

 

[MPGmustang]

well got the new chip... and it idles better

I drove it and at first I'm like WOW, big difference on acceleration, much more responsive... got to 50mph, then started cruising... and all power seamed like it just 'cut out' I let go of throttle and shift to neutral, it idles, I give it gas and it putters... VACUUM LEAK!!!!

Anyways I get around the corner off the main road and I'm sitting on the side of the road idling and two motorcycle cops pull up next to me checking out what I'm doing, and I'm like 'idling the new computer' MAN I GET PULLED OVER EVEN IN MY OWN NEIGHBORHOOD!!!

slowly got it home, by slowly I rev'd to 3k rpm and dropped it to 1st gear, it didn't want to but I got it home where I turned her off.

I'm going to unplug all spare hoses, lines, everything, then JBweld the outside of the 2bbl conversion, I got to be able to find this leak... it's massive.

yup, you did read that right, I'm getting hitched... lol

 

[MPGmustang]

http://s897.photobucket.com/albums/ac17 ... 113402.jpg

ouch...
it's $100 for Elmo to fix it, Elmo is Classic inlines head builder... I think I'll have it re-done.

 

[xctasy]

No worries, its just time and repair then by braising.

Its handy to have a spare D7 to EOBE 6050 head and change to the adaptor to the Holley 2-bbl to 1.75" hole item as a stand in, but there's valve springs, seals and a head gasket and your time to factor in, propably not worth it. I used my old 1965 vintage C1 coded 170 head as a provisional measure, and its been the best piece of metal around. I got it for nothing from a barsadatised 1968 XT Falcon convertible, which had a 1966 engine with 1965 170 head which was no different from the first 1961 Falcon 170. A 47 year old head on a 31 year old Mustang, says something like hell for stout, doesn't it?

Cast iron can on occassions be a little hard to work with. Have you considered Araldite? Its propably the best two pot mix around and its used on turbo cylinder heads. One person here dropped his 170 engine, and used a two pot glue to hook the shatterd front edge of his dog turd log head, and it worked fine.

 

[bubba22349]

http://s897.photobucket.com/albums/ac17 ... 113402.jpg

ouch...
it's $100 for Elmo to fix it, Elmo is Classic inlines head builder... I think I'll have it re-done.

sorry about the trouble your having, that would be quite a vacuum leak

 

[MPGmustang]

sadly I can't afford the $500+ for brazing... it's $300 for brazing and $200 to reinstal the valve guides due to the intense heat for the the brazing. it would be best but can't afford it. for now I'm fixing it... cheap and quick

 

[MPGmustang]

just updataing, had sergery a week ago, recovering and can't lift anything for 2 more weeks, so the mustang is on hold, CI head builder Elmo called me and informed me that the Putty came in, he has a few orders right now so I can't do much and we scheduled the head job the 2nd weekend of oct. so it's planned now I just have to get it dismantled.

I'm going putty, it's a $100 fix, eventually I'll probably replace the head with an OZ-250 head. so it's in the plans.


had to get myself a comuter, a 2000 chevy cavalier with a i4 2.2L... not too bad for my first 'modern' car. so the mustang will turn into a weekend cruiser which is good for a car that likes to break and my broke as a joke pocket book...

 

[CoupeBoy]

Congrats on the nuptuals, bummer on the surgery..

I was digging the progress on this thread and then.. blindsided by a crapolier . My Step-Dad had one, I think my Ford inclined family ridiculed him until he sold it. I am not anti-GM btw.. '94 GMC and '12 Tahoe parked at my house, I just like saying "Crapolier".

I've been gone a while from the forum, but I assume that you did the 2v conversion on the factory 1bbl head?

 

[falcon fanatic]

I'm diggin this thread. sorry to hear about the big crack in your head, and the broken body. This winter I'm going to try and do a megasquirt-based CFI conversion on my Falcon, so watching your progress has been enlightening. Just moved to Colorado from sea level, so I'm appreciating the advantages of FI - retuning my weber for the 100th time has been a drag, but at least I'm good at it now.

 

[MPGmustang]

Congrats on the nuptuals, bummer on the surgery..
I was digging the progress on this thread and then.... I am not anti-GM btw.....
I've been gone a while from the forum, but I assume that you did the 2v conversion on the factory 1bbl head?

\

surgery went great, I'm relieved... I'm not anti-GM either, I just happened to have 2 fords as my first 2 cars...
Yes I do have the 2bbl conversion, I have the putty buildup and guess it doesn't hold very well...

I'm diggin this thread. sorry to hear about the big crack in your head, and the broken body. This winter I'm going to try and do a megasquirt-based CFI conversion on my Falcon, so watching your progress has been enlightening. Just moved to Colorado from sea level, so I'm appreciating the advantages of FI - retuning my weber for the 100th time has been a drag, but at least I'm good at it now.

Body is fixed .... head is another story, I wish I could do more....