Engine No Worky Work!

Mike Holt

Member
was going to head down to Tailgate Tuesday with Phil Mead. Hit the key and it initially hesitated. Then turned over a couple of time before firing. Running REALLY rough. Have to keep feathering the accelerator to keep it running.

I pulled the line from the fuel regulator and didn't see any water in the gas. But, honestly couldn't get a great sample there.

#40 of fuel pressure at the regulator (running #30 injectors)
Mass-Flo EFI

Take a listen

 

Mike Holt

Member
So, Chris from Mass-Flo called and gave me a few things to check. First test and it failed! He wanted me to see if the fuel pump was priming then shutting off...it isn't. He then had me pull the chip and check again...still failed. From what he said and from the posts I've read on several different forums, the A9L computer is dead. Of course it has a chip burned for it and I'm running #30 injectors so another stock computer won't work.

Somebody remind me again why we enjoy this hobby!
 

Scott Harrison

"Growing old is mandatory, growing up is optional"
Staff member
Contributing Member
Member
I think I have a spare A9L you can borrow to test. Also, I gave Wade one with a chip on it. Maybe Beth can locate it.
 

Scott Harrison

"Growing old is mandatory, growing up is optional"
Staff member
Contributing Member
Member
BTW, when Jack Goehring couldn't get his EFI powered Cobra to run without stopping after an hour, I converted it to carb. Cost was a about $2k for intake, carb, dizzy, fuel pump etc. Starts and runs great now. He loves driving it now without fear of being stranded.
Ever wonder why (king of Cobra techs) Wade Chamberlain converted his Cobra to carb from EFI?
Just sayin....
 

TroyT

Contributing Member
Member
Mike,
If it is computer related, can you start with the stock A9L computer and burn a chip that matches your set up? Send Chris 3 parts: a stock A9L computer; the mass air sensor in the air cleaner; and the mass air converter or whatever the little black box does to convert the GM mass air sensor info. in the air cleaner to the Ford computer.
With those three parts he should be able to make it work. That is what I did for my cold start issues. I wonder if this would help to straighten out issues with your car. This may be cheaper than replacing the computer with the Pro-M computer unless the cost is comparable. Just a thought..
 

Mike Holt

Member
So I did a bit of research today. It appears the A9L is famous for the three capacitors failing over time. A simple removal and solder in new corrects the issue 90% of the time. I took my computer apart today and sure enough there is corrosion on one of them. So, a $7.95 order from Mouser electronics and hopefully, I'll be up and running again.

Just to verify, I put in an old SD computer I had on the shelf and the pump primed and shut off just like advertised. So, pretty sure I've found the issue.

The new Pro-M setup, while I'm sure is very nice and certainly an upgrade from the old setup, starts at $1995.95. Not prepared to go that route just yet, when it's been running so well with what I have. Maybe a winter upgrade in the future.
 

TroyT

Contributing Member
Member
I am having the same problems now. I remembered this thread, searched, and located it. I will look into this.
My car runs rough from idle to at-speed. I had to bump up the fuel pressure a little to 40# with the vacuum hose removed. I replaced this vacuum hose and the PCV hose thinking there may be a leak somewhere in the hoses. I cleaned the mass air sensor, the throttle body primary and secondary plates, reset the computer by unplugging the harness to it. I even disconnected the battery to reset the computer (A9L). I don't believe its the gas. I topped off half a tank of gas in January and added Stabil. Connections to sensors seem fine. I'll dig into the A9L and see if I see anything there.
 

TroyT

Contributing Member
Member
Mike did you use the same voltage capacitors as the factory ones or install higher voltages ones (knowing the uf rating remains the same)?
 

Rob Burton

Contributing Member
Member
Troy, My Mass Flo injection system acts this way whenever the gas gets old. Top it off with some premium gas and add a full bottle of good octane booster. Drive it around the neighborhood and you should see quick improvements..
 

TroyT

Contributing Member
Member
Okay. I'm suspecting this too. Half of the tank is from last September and I topped it off with fresh gas in January with some Stabil. It's still full. I put in a gas treatment last weekend. That didn't seem to help. I may siphon the gas out and fill with fresh premium gas. I also removed the A9L and took it apart to look at the capacitors and one of them seemed loose from corrosion. While it's open, I will go ahead replace all three of them as Mike did. If this is not the problem, at least I have replaced them before they leak all over the circuit board.
 

Mike Holt

Member
Sorry Troy. Just seeing this now.
I used the standard capacitors on my rebuild. But, ultimately it did not fix the issue. It would fire up and run great. The next start would run like crap again.
I ended up replacing the entire system with the new Pro-M (Mass-Flo next) injection system. Not a bad system, but pricey. And as far as “Plug and Play”....not so much! “Plug and Pray” was more like it. Took me almost a month to get it sorted. Chris is extremely knowledgeable. But, getting a straight answer was sometimes difficult. In the end, I am very happy with it. Just not an easy install.
If I had to do it over, I probably would go with the FAST EFI.
 

TroyT

Contributing Member
Member
Thanks Mike for your response. I am replacing the capacitors, plan to siphon out the gas (old gas), and Chris suggested the IAC valve may be the culprit. I hope one or all of these fixes the problem. I feel like I"m fartin' in the wind to fix this problem.
 

TroyT

Contributing Member
Member
I'll continue this on a new thread. I'll list all the things I have done so far with no success in getting this heap to run right. Thought I'd throw this out there for some troubleshooting ideas...or just shoot the damn thing. :eek:
 

rkite

Member
I'd like to see what the plugs look like. If one is off you can narrow it down. It's not unheard of for an injector to go bad.
 

Scott Harrison

"Growing old is mandatory, growing up is optional"
Staff member
Contributing Member
Member
We already checked that. They all looked normal.
 
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