Assistance in diagnosis of sudden starting issue.

Decipha's custom GUFX strategy covers all 89-93 foxbody ecu's including the 88 mass-air california ecus.
71Mavrk
Posts: 46
Joined: 2021 Jun 01, 20:13
Location: Reno, nv
Vehicle Information: 1971 Maverick
Ford Racing 39# injectors
Maf 90 mm
AFR 185 Renegade 58 cc aluminum heads
icon forged pistons, 9.5 CR 347
comp Cams XE-270-HR
wbo2_zt3

Assistance in diagnosis of sudden starting issue.

Unread post by 71Mavrk »

I’m looking for some advice on an issue that suddenly developed.

Here is the car. All the specs can be found at the bottom of the page:
https://performance.ford.com/enthusiast ... =875565702

The car was running fine. She sat for about six weeks and was on a charger.

Upon going to start her up, with the key on, the first thing I notice is the fuel pump keeps running. Usually, I turn the ignition on and let the pump come up to pressure. I can hear it stop. Then I crank her over and she starts right up.

This time, I crank and get nothing. Fuel pump keeps running. With some throttle, she will fire but runs like crap. Loud raspy exhaust. Smells rich. Will not keep running without some throttle.

I unplugged the battery and let her sit for a while. With the key on, the pump is running. When I crank with no throttle, she will start and run for just a second or two. I can get her to run with the throttle open but once again she sounds like crap. As soon as I let off the throttle, she dies.

I’m at a loss as to how she would suddenly develop this issue after just sitting for a few weeks in the garage. I’m more into old cars without computers. So, I’m at a bit of a loss as to what could be the issue and how to diagnose.

Any suggestions are welcomed.

Thanks,
Micah
decipha
Posts: 4954
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Assistance in diagnosis of sudden starting issue.

Unread post by decipha »

the qh battery died
71Mavrk
Posts: 46
Joined: 2021 Jun 01, 20:13
Location: Reno, nv
Vehicle Information: 1971 Maverick
Ford Racing 39# injectors
Maf 90 mm
AFR 185 Renegade 58 cc aluminum heads
icon forged pistons, 9.5 CR 347
comp Cams XE-270-HR
wbo2_zt3

Re: Assistance in diagnosis of sudden starting issue.

Unread post by 71Mavrk »

Interesting. I would have never even thought to look at the battery. I will give that a shot and report back.

Thanks for taking the time to reply.

Micah
71Mavrk
Posts: 46
Joined: 2021 Jun 01, 20:13
Location: Reno, nv
Vehicle Information: 1971 Maverick
Ford Racing 39# injectors
Maf 90 mm
AFR 185 Renegade 58 cc aluminum heads
icon forged pistons, 9.5 CR 347
comp Cams XE-270-HR
wbo2_zt3

Re: Assistance in diagnosis of sudden starting issue.

Unread post by 71Mavrk »

Well, that was fun. My computer is in a real fun place to get to. Ford didn't give the Maverick any extra room. To install the computer, we cut into the A pilar/front fender area just behind the firewall. We then made a box that sits in the space between the fender. (see picture) The computer and the fan controller just barely fit in there with half of the access blocked by the AC condenser box. Thankfully, I barely had enough room to partially open the door so that I could remove the side panels to access it. Then I got to contort myself to reach up, pull it all out, change the battery and jam it all back in there.

Uploaded the tune and she fired up on the first try.

Now, I can move her and get better access to put it all back together the was it was.

Thanks Michael, I would not have suspected the battery. We started tuning in January 2016. So, I cannot complain and just have to remember to replace it again before I get stranded.

Micah
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red5.0fogger
Posts: 148
Joined: 2021 Mar 22, 15:58
Location: Newington CT
Vehicle Information: 1986 Mustang GT, Stock block, TFS 170 Heads , N41 cam, ported cobra intake, nitrous, T5 , 3.73s

Re: Assistance in diagnosis of sudden starting issue.

Unread post by red5.0fogger »

Did your QH battery have to be unsoldered or was it the pop in kind? glad you got it fixed.
71Mavrk
Posts: 46
Joined: 2021 Jun 01, 20:13
Location: Reno, nv
Vehicle Information: 1971 Maverick
Ford Racing 39# injectors
Maf 90 mm
AFR 185 Renegade 58 cc aluminum heads
icon forged pistons, 9.5 CR 347
comp Cams XE-270-HR
wbo2_zt3

Re: Assistance in diagnosis of sudden starting issue.

Unread post by 71Mavrk »

Me too!

No soldering involved. It just clipped in place.

I got all the panels back in place and took her around the block. I hope I don't have to do that for at least six years. Next time, I will be proactive so that I do not get stranded or stuck in the garage where I can barely open the passenger door.

Micah
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