• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

Help me get my '69 running good! EFI/351w

  • Thread starter Thread starter streetgrande69
  • Start date Start date Feb 10, 2009
  • 1
  • 2
Next
1 of 2 Next Last
S

streetgrande69

Founding Member
Nov 2, 2002
976
0
16
Splendora, Tx
Feb 10, 2009
#1
  • Feb 10, 2009
  • #1
Well, I guess it’s time, i've been away for a LONG time!
I need my car running so I can drive her!!! I hate going into the garage having her looking at me begging to make a trip down some twisty road hugging the payment. I’ve put way too much time and money into this car for it to sit unused!

Here is a quick history.

About 2 years ago I rebuilt the 351w and added mass-flow EFI ( Mass-Flo Fuel Injection Systems ). I can work on cars with carbs all day….EFI kinda gets me though, I understand how it works and I just have issues tuning it I guess, I really don’t know. I assume it’s the efi but at the same time I rebuilt the motor as well so I may have screwed it up but I think I covered my bases. This is my 3rd 351W and it was straight forward, nothing real special. I could go through and dig up all the specs I have on the cam and springs, lifers etc if that would help.
It fires right up like id expect it but after that it idles high and dies if I don’t feather the gas pedal to keep it running. I can drive it but it really doesn’t feel like it’s smooth at all.
I do not get any codes from the computer at all. I did in the beginning but I cleared all of them with help from the guys at mass-flow.

So please take a few minutes and ask some question and give me a hand, I’ll do my best and if you guys get my '69 on the road........I will be extremely grateful!!!!
 

woodsnake

15 Year Member
Jan 16, 2007
1,352
15
69
Hicksville, NY
Feb 10, 2009
#2
  • Feb 10, 2009
  • #2
What intake? What throttle body? What codes were you getting, and how did you clear them?

Starts and idles fine, and then, chokes out? Ignition? Coolant temp sensor?
What is your fuel pressure?
 

mrmustangman357

Member
Feb 11, 2007
763
3
18
Feb 10, 2009
#3
  • Feb 10, 2009
  • #3
any air leaks? all components connected?
 
S

stonecoldtx

Member
Aug 4, 2007
214
2
18
Dallas, TX
Feb 11, 2009
#4
  • Feb 11, 2009
  • #4
streetgrande69 said:
Well, I guess it’s time, i've been away for a LONG time!
I need my car running so I can drive her!!! I hate going into the garage having her looking at me begging to make a trip down some twisty road hugging the payment. I’ve put way too much time and money into this car for it to sit unused!

Here is a quick history.

About 2 years ago I rebuilt the 351w and added mass-flow EFI ( Mass-Flo Fuel Injection Systems ). I can work on cars with carbs all day….EFI kinda gets me though, I understand how it works and I just have issues tuning it I guess, I really don’t know. I assume it’s the efi but at the same time I rebuilt the motor as well so I may have screwed it up but I think I covered my bases. This is my 3rd 351W and it was straight forward, nothing real special. I could go through and dig up all the specs I have on the cam and springs, lifers etc if that would help.
It fires right up like id expect it but after that it idles high and dies if I don’t feather the gas pedal to keep it running. I can drive it but it really doesn’t feel like it’s smooth at all.
I do not get any codes from the computer at all. I did in the beginning but I cleared all of them with help from the guys at mass-flow.

So please take a few minutes and ask some question and give me a hand, I’ll do my best and if you guys get my '69 on the road........I will be extremely grateful!!!!
Click to expand...

Your post indicates that you contacted the Mass Flo guys in order to get the codes reset, but since they designed the computer system, don't they have any ideas as to how to help you?

I mean, JEEZ--if they built it, they OUGHT to know what would cause it to act the way it is on your engine, right?

Trying to troubleshoot their computer without any knowledge of what and how they have it constructed and coded would be the same as some Ford enginer trying to diagnose a problem with a Chevy computer, so I'd hate to hazard a guess!

From what you're describing, it SOUNDS like you're running extremely lean; you don't indicate whether the behavior changes when the engine warms up or not.

If it doesn't, then you *might* have a vacuum leak, but if it does, it would likely be related to the tune that's in the computer, and if that's the case, if there aren't forums out there dedicated to this specific system, then if it were me, I'd be calling the support line for this manufacturer!!
 
S

streetgrande69

Founding Member
Nov 2, 2002
976
0
16
Splendora, Tx
Feb 12, 2009
#5
  • Feb 12, 2009
  • #5
Here is a video i took this evening, it's hosted on myspace, hopefully it helps clearify what i mean by it running badly. as you can see it fires right up, stumbles and the dies at the end. i di not touch the gas pedal in this video.

1969 Mustang Mass-Flo EFI Video by Eric - MySpace Video

Here are all my car pix with alot of build pix on this engine and EFI system in there too.
http://trinityandhailey.com/EFI.htm



I have talked with Chris @ Mass-Flow for a few hours, he's called me back quickly and I haven't had any issues with him other then not getting the system running well. I just haven’t talked to him in over a year and a half. He helped me back probe the tps and check it with a meter over the phone.
I do agree with you, I know this is a long shot to ask you guys for help on a forum is like a needle in a hay-stack.

Here are as many engine specs as i could collect. I’ve moved twice since this and been deployed to the gulf for 10 months in between this build up so I’m trying my best.

Here are as many specs on what is on this car as I have, sorry for all the links, I figured you could get more info from the link then I could ever give you.
The EFI kit came with
30# injectors
MAF calibrated to match. I’ve already sent it back once to have it checked and recalibrated.

Heads are Windsor Sr.’s these are not new. I replaced the springs and rocker arms but not the valves. 200cc, valves are 2.02x1.600 11/32, 58cc chamber

Cam lifter kit K35-242-3
Here is a link to the exact kit I used
http://cgi.ebay.com/ebaymotors/Comp...W0QQitemZ370152299273QQcmdZViewItemQQimsxZ200 90130?IMSfp=TL0901301510006r6756

Fuel regulator and summits 100 psi gage.
Mallory 4305M - Mallory Universal Fuel Pressure Regulators for Fuel Injection - summitracing.com

Distributor is, I think, a Mallory 7968704, I can look when I get home but the sheet I got is the exact same as this link.
http://static.summitracing.com/global/images/instructions/maa-7968704.pdf

Pistons are Probe SRS 12355-30.
Probe Industries


Rings
http://www.sdpc2000.com/product/ACX9902-30/4030116116316.aspx

I hope this helps, if there are any items you need to help me out, let me know. I can take pictures and do videos as need to give you a hand.
 
S

stonecoldtx

Member
Aug 4, 2007
214
2
18
Dallas, TX
Feb 12, 2009
#6
  • Feb 12, 2009
  • #6
streetgrande69 said:
Here is a video i took this evening, it's hosted on myspace, hopefully it helps clearify what i mean by it running badly. as you can see it fires right up, stumbles and the dies at the end. i di not touch the gas pedal in this video.

1969 Mustang Mass-Flo EFI Video by Eric - MySpace Video

Here are all my car pix with alot of build pix on this engine and EFI system in there too.
MASS-FLO EFI CONVERSION



I have talked with Chris @ Mass-Flow for a few hours, he's called me back quickly and I haven't had any issues with him other then not getting the system running well. I just haven’t talked to him in over a year and a half. He helped me back probe the tps and check it with a meter over the phone.
I do agree with you, I know this is a long shot to ask you guys for help on a forum is like a needle in a hay-stack.

Here are as many engine specs as i could collect. I’ve moved twice since this and been deployed to the gulf for 10 months in between this build up so I’m trying my best.

Here are as many specs on what is on this car as I have, sorry for all the links, I figured you could get more info from the link then I could ever give you.
The EFI kit came with
30# injectors
MAF calibrated to match. I’ve already sent it back once to have it checked and recalibrated.

Heads are Windsor Sr.’s these are not new. I replaced the springs and rocker arms but not the valves. 200cc, valves are 2.02x1.600 11/32, 58cc chamber

Cam lifter kit K35-242-3
Here is a link to the exact kit I used
http://cgi.ebay.com/ebaymotors/Comp...W0QQitemZ370152299273QQcmdZViewItemQQimsxZ200 90130?IMSfp=TL0901301510006r6756

Fuel regulator and summits 100 psi gage.
Mallory 4305M - Mallory Universal Fuel Pressure Regulators for Fuel Injection - summitracing.com

Distributor is, I think, a Mallory 7968704, I can look when I get home but the sheet I got is the exact same as this link.
http://static.summitracing.com/global/images/instructions/maa-7968704.pdf

Pistons are Probe SRS 12355-30.
Probe Industries


Rings
Akerly and Childs 4.030 1/16 - 1/16 - 3/16, 9902-30

I hope this helps, if there are any items you need to help me out, let me know. I can take pictures and do videos as need to give you a hand.
Click to expand...

By chance, have you checked the fuel pressure?

Also, what about the fuel filter--have you thought about maybe changing that out?

Just a couple of random thoughts after viewing the vid . . .
 
1

10secgoal

Active Member
Dec 1, 2003
2,801
3
49
San Diego
Feb 12, 2009
#7
  • Feb 12, 2009
  • #7
Is it fine after you warm it up ? I mean, if the start up enrichment isn't enough, she could just be lean....Can you tune that system that detailed
 
S

streetgrande69

Founding Member
Nov 2, 2002
976
0
16
Splendora, Tx
Feb 12, 2009
#8
  • Feb 12, 2009
  • #8
no, it's still crappy after it's warm
 
S

streetgrande69

Founding Member
Nov 2, 2002
976
0
16
Splendora, Tx
Feb 12, 2009
#9
  • Feb 12, 2009
  • #9
fuel psi is set @ 32 psi.....guess i should adjust huh
 

BarnStang

Founding Member
Mar 2, 2001
1,260
3
39
Hagerstown, MD
Feb 13, 2009
#10
  • Feb 13, 2009
  • #10
Bring the fuel pressure up. 2psi at a time and see how it does. Don't ramp in a bunch of fuel pressure all at once. I wrote a bunch last night and my wireless connection to the laptop dropped. Lost my post...also, what is base timing set to? Does this system function like a Ford efi system in that you have to disable the computer input to set base timing? (i.e. SPOUT connector). I would guess 12 degrees base would be a good starting point if you have 93 octane in the tank, 10 degrees if you have 87. Or call the tech support and get a recomendatin on that.
 

woodsnake

15 Year Member
Jan 16, 2007
1,352
15
69
Hicksville, NY
Feb 13, 2009
#11
  • Feb 13, 2009
  • #11
It sounds like it is losing ignition to me as well......
 
S

streetgrande69

Founding Member
Nov 2, 2002
976
0
16
Splendora, Tx
Feb 13, 2009
#12
  • Feb 13, 2009
  • #12
BarnStang said:
Bring the fuel pressure up. 2psi at a time and see how it does. Don't ramp in a bunch of fuel pressure all at once. I wrote a bunch last night and my wireless connection to the laptop dropped. Lost my post...also, what is base timing set to? Does this system function like a Ford efi system in that you have to disable the computer input to set base timing? (i.e. SPOUT connector). I would guess 12 degrees base would be a good starting point if you have 93 octane in the tank, 10 degrees if you have 87. Or call the tech support and get a recomendatin on that.
Click to expand...

Yes when setting base timing, you do need to have the spout disconnected, off the top of my head I do not know what I have base set to.

As I get further into this, I need to maybe take a step back and start from square one on final adjustments. It's been so long that I can't remember half of this stuff. I'm gonna try to make some good progress this weekend and give you guys a full report as soon as I do.

I am greatly appreciative of your help though! It’s nice to be back in the saddle again! Being away from your car for so long it tough!
 
B

bnickel

Founding Member
Aug 21, 2002
5,640
3
77
lubbock, texas
Feb 13, 2009
#13
  • Feb 13, 2009
  • #13
streetgrande69 said:
Yes when setting base timing, you do need to have the spout disconnected, off the top of my head I do not know what I have base set to.

As I get further into this, I need to maybe take a step back and start from square one on final adjustments. It's been so long that I can't remember half of this stuff. I'm gonna try to make some good progress this weekend and give you guys a full report as soon as I do.

I am greatly appreciative of your help though! It’s nice to be back in the saddle again! Being away from your car for so long it tough!
Click to expand...



Eric, don't forget to pull the dizzy and make sure the gear is the correct cast iron gear and not the steel gear otherwise your cam will be toast in no time, if it isn't already. i'm sure they probably sent you a dizzy with the right gear for your cam but you never know, so double check it
 
S

streetgrande69

Founding Member
Nov 2, 2002
976
0
16
Splendora, Tx
Feb 13, 2009
#14
  • Feb 13, 2009
  • #14
will do this weeken d B, i'm gonna also go through as many items posted on these forums as i can.
 
S

streetgrande69

Founding Member
Nov 2, 2002
976
0
16
Splendora, Tx
Feb 16, 2009
#15
  • Feb 16, 2009
  • #15
Before I start….this is long, I’m sorry!!!
Okay, I worked on the car this weekend; I think I got it a little better. It still has poor power and feels like to me that it’s not firing on all 8 and has poor idle quality. I also have a brake issue that I will be addressing shortly after this is figured out.
I started out by pulling the distributor to check the gear to make sure it’s in good shape as suggested.
I stabbed the distributor and set base timing as follows
Unplugged the spout
I put the motor on TDC #1. Verified #1 by pulling #1 plug and checking.
I have the cap marked for TDC and 10 Deg BTDC.
I rotated the engine by hand to 10 deg BTDC, I have an aftermarket damper that is very easy to read.
Then I pulled the wire from #1 and put a screw driver in it. Put the ignition to the on position. Rotated the distributor and held the screw driver close to a ground and as soon as it fired, I stopped rotating the distributor. Tightened the hold down.
Started the car.
Checked fuel psi and it was about 32. Unplugged the vacuum line and plugged the line. I slowly readjusted to 40 PSI, tightened the locknut. In the instructions it doesn’t say to reconnect the vacuum line, so I left it off and plugged. It didn’t seem to make a difference if it was plugged in or not.

I didn’t really check idle speed because I think my tach-dwell is broke or seriously in question…..I dropped it. it seems to be high enough when warm. So I never unplugged the IAC for any reason.

Then I unplugged the battery for 30 minutes or and restarted the car. It starts right up and idles roughly when warm and does not stall out like in the video.
I took it down the street to see how it would run and it is still pretty bad still.

Here is the list of stuff which, in my opinion could be off or wrong based on information I’ve gathered in the last week for several sources.

As suggected by others

Bad head/piston/cam combo. Compression is too high. I personally don’t know how to calculate my compression but did go over all the specs with the machinist when I was putting the combination together. My goal was 10/10.5-1.

Wrong plugs for my combination. Once again, I don’t know how to figure out which would be best for what I have. I also have not changed my plugs since I’ve built this motor, remember this motor has maybe 50 miles on it.

Incorrect base timing, it is 10 DEG BTDC right now.

I flushed the fuel line for about a minute before I connected everything up but could I have put foreign material into the injectors? I have an Aeromotive 10 micron post filter for the system.


Possible vacuum leak but I’ve looked and felt and sprayed wd40 and can’t seem to find much. I can’t really reach behind the intake, it’s pretty tight. Is there a way to check? How do I do a smoke test as someone suggested?


Improper valve seat sealing. I bought the heads from a friend and did not lap the valve in. could these maybe be bad valve/seat contact? How would I check?


Misadjusted rocker arms? I’ve never had aftermarket heads on any of my cars, everything was stock before. I now have Comp Cams adjustable rockers. I followed the directions to a “T”….actually these are the ones I used….. “Adjusting Hydraulic Lifters for Proper Preload” CraneCams
After I built the motor, I printed this out, removed all the plugs from the motor so it would be easier to rotate and did each cylinder just as the link suggests. I would like to think I did this correctly but how do you know you got it exactly right, you relying on the feel of the push rod for your adjustment.

If you've got this far, thanks for taking the time, please give me your 2 cents.
 
B

BubbaB1966

New Member
Nov 2, 2008
30
0
0
Fort Walton Beach, Fl
Feb 27, 2009
#16
  • Feb 27, 2009
  • #16
If your brake problem is soft/no power brakes, pull your vacuum line to the booster and see if both problems are cured. You may have a vacuumleak through a bad brake booster.

Just a thought.
 

65ShelbyClone

Founding Member
Sep 9, 2000
4,675
38
119
Antelope Valley, SoCal
Feb 28, 2009
#17
  • Feb 28, 2009
  • #17
I didn't see any mention of a wideband oxygen sensor. That would help quite a bit IMO.

If your fuel pressure regulator has a port for manifold vacuum, it should be hooked up.
 

BarnStang

Founding Member
Mar 2, 2001
1,260
3
39
Hagerstown, MD
Feb 28, 2009
#18
  • Feb 28, 2009
  • #18
Make sure you check that vaccum line on the FPR, it should be dry. If it's wet with fuel, the diaphram is leaking by=FPR is toast...
 

socalwrench

New Member
Mar 7, 2009
26
0
1
Mar 8, 2009
#19
  • Mar 8, 2009
  • #19
Wow, lots of information to sort through. Personally, I love fuel injection- much easier to keep tuned and is much more efficient than a carburetor. I have a few things that concerned me.

First, if the computer was giving you codes- read them. They are there to help. Clearing the codes doesn't fix what's causing them.

Second, the guys at Mass-Flo should tell you what the fuel pressure is supposed to be, BOTH from the fuel pump, and then at the fuel rail (after the regulator).

Third, one of the first things I would check is the MAF sensor. Most of them are very touchy, especially the wire type (most accurate, but can easily become coated with oil).

Fourth, like someone stated above- your first oxygen sensor (o2) is the PRIMARY input for the computer to adjust the air/fuel mixture (A/F). Be sure that it's the correct type, in the correct location and that it's not damaged.

Next, if all the wiring is fine and assuming that you have the correct tune for your setup, I would begin checking the ignition system. Spark plugs can be a great indicator to see it the A/F is correct.

Finally, assuming you have headers, I would check to see how much heat each cylinder is producing (please don't burn yourself). While you can do a dry and wet compression check or cylinder leakdown test, reading the temperature at the primary tubes is a quick indicator if a cylinder is firing correctly. A cheap infrared temperature meter comes in handy.

It's extremely difficult to determine an electronics problem without having the car in front of me. Perhaps the engine has gone into 'fail safe' mode and is running extremely rich. Keep us updated, I'm sure we can figure it out.
 

69gmachine

Member
Dec 2, 2004
576
2
19
Southern Maryland
Mar 8, 2009
#20
  • Mar 8, 2009
  • #20
socalwrench said:
Wow, lots of information to sort through. Personally, I love fuel injection- much easier to keep tuned and is much more efficient than a carburetor.
Click to expand...

Much easier? I would have punted by now, thrown a good ol' reliable carb on and be done with it!

I'd agree that EFI is a little more efficient, but a well tuned carb can be very close.

I do hope you get it sorted out soon streetgrande. I wish I could offer some helpful advice, but I can't. Fortunately there are plenty of smart guys on this forum and I'm sure you'll get it figured out eventually. Hang in there man!
 
  • 1
  • 2
Next
1 of 2 Next Last
You must log in or register to reply here.

Similar threads

S
Fox '87 GT can't get to stay running
  • spilly
  • Mar 29, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
27
Views
819
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 20, 2026
spilly
S
M
Too much for me to repair in my current housing situation
  • My Drama Magnet 04 Gt
  • Apr 1, 2026
  • The Welcome Wagon
Replies
8
Views
296
The Welcome Wagon Apr 14, 2026
Noobz347
H
Ongoing Battle With Hydraulic Lifters
  • hailer06
  • Jun 8, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
7
Views
289
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 9, 2026
Noobz347
A
Check Engine codes jumping around
  • azactor
  • Jan 9, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
189
1996 - 2004 SN95 Mustang -General/Talk- Jan 10, 2026
gkomo
Z
Progress Thread zeth194 - New Guy on the Block
  • zeth194
  • Mar 19, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
10
Views
567
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 26, 2026
LILCBRA
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?