Possible Fuel Pump Issues...

[CornerCarvin67]

Hey friends....

I spent the past hour searching for answers and think it's probably in the fuel pump area. Not being much of an electrical guy... and lacking the tools (volt meter) and such. I was hoping that maybe some of you could give me a different approach to diagnosing my problem. I found one post this morning that described the symptoms somewhat... but not entirely. Also... I got one other ingredient to add. I was on my way home a few weeks ago and decided to put down a nice pair of patches in a new subdivision under construction by my house. It was safe... nobody around. After a few failed attempts (I have big feet... ha ha). I got her lit pretty good. After a few seconds I let off the brake and let her roll out. Very nice burn. Anyhow... the car is not a daily driver... and after a few days I was taking her out to take the kids to the dentist. About five miles from my house without warning she starts to bog.... like a bad carb. I can't seem to get it to respond at all to throttle. I push in the clutch and it's the same thing... bogging badly. I pull over.. pop the hood... and it seems to run fine. I gave it throttle...... no problems. So I continue on my way... kids gotta get to the dentist. A few miles later and it's doing it again. I pull over and turn the car off..... turn it right back on and it fires up with no issues... runs fine. WTF. After the dentist the whole ride home was just fine. No issues. We get back from vacation the other day and I'm taking my son to the park and about two miles from my home it starts bogging again. After a buddy suggested it may be the FP... I do a u-turn quick to get her home and avoid being stranded. I put her in the garage at idle and wait for the bogging to return. It didn't happend. So I just left it. I DID notice however that the typical Mustang loud fuel pump noise was not present. Is that a good indicator of a fuel pump on the fritz? I read that a bad FP relay switch may also cause this bogging issue? I have a 92.... completely stock with 37k miles on it. The car before me obviously led a quiet life. But why would this problem come up after my burn out abuse? The car has run perfect in the last year that I've owned it.

Thanks for taking the time to read the long thread.....

I hope to get help/opinions...

 

[jrichker]

For the DIY Mustang guy, a good DVM is a must have item, just like wrenches and a timing light. Radio Shack, Home Depot and Lowes all have inexpensive DVMs for less than $30.

Electricty isn't difficult. I started out at age 10, wiring flashlight batteries to make toy motors, buzzers and lightbulbs work. If a 10 year old kid can do it , so can you. Most automotive circuits aren't any more complicated than the toy motor, buzzer and lightbulbs.

For a free short course in automotive electrical systems, see Basic Automotive Electrical
You can go through the course in less than 30 minutes and learn enough to do simple stuff with no problems.

First of all dump the codes to see if the computer picked up any odd problems with the fuel pump electrical circuit or anything else. Codes may be present in the computer even if the Check Engine light isn’t on.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

See Troublcodes.net Trouble Codes OBD & OBD2 Trouble Codes and Technical info & Tool Store. By BAT Auto Technical

If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

Do not jumper anything to the single dark brown connector. It is the power for the under the hood light. It is in another bundle of wires near the windshield wiper.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see EQUUS DIGITAL FORD CODE READER (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

 

[CornerCarvin67]

You are exactly correct. For as long as I've been playing with cars... I should expand my knowledge of the electrical workings. Problem is.... I'm lazy!! Really though.... I did look at your diagram as was going to try the jump diagram you attached. First thing I noticed was the single connector you have labled having a red/white wire isn't true in my case. My single connector has a tan/brown wire to it. The main connector does however have a red/white wire.

Then I looked at the whole thing again and my connector doesn't look anything like the one shown.

More reason why I'm a MECHANICAL designer.... not electrical.

I suppose I could simply drive the car to Autozone and let them plug it in. Hopefully the car won't die on me. I did get home tonight and started it up just fine with no issues. The pump primed well. I could faintly here the FP also while running. I didn't get the chance to drive it however.

It's just bugging me that the car is completely un-molested and now it's having this tricky little issue. I was hoping someone would read this thead and could relate to give me a direction to go on. It just seems weird that it's NEVER given my a problem until I did those burnouts. What could possibly have changed or got hurt??

Oh well.... off to Autozone when I get a chance. Thanks for your time.

 

[CornerCarvin67]

My research....

Okay.... I'm at work and spent my lunch our trying to research my problem. I won't have a chance to get to Autozone until this week to dump codes. But I figured I should do my end by educating myself a little bit more. I'm HOPING that dumping the codes will point to one of these following issues. I'm gonna be ticked if it dumps clean. Cuz then where do I look?

Here is a list of my notes from threads I've read... in no particular order:

1. One person mentioned pulling the Neg cable off the battery for 30 minutes to let the ECU reset. This is free.... Will it work? Probably not... but I'll try it, right, why not?

2. Many suggested a MAF issue. Man... would it be bad luck if this was the problem? I should remind everyone the car has only 37,xxx original miles. I really should not be "wearing" anything out, should I? Is there a test I can perform easily to give more evidence of failure?

3. Fuel pump relay. No clue what it does or where it's located. Is it under the drivers seat on my 92'? Sounds like a cheap and easy fix.

4. Stuck open EGR valve. Someone suggested unplugging the vacuum line from the EGE valve and plugging the hose. Drive the car and see if the problem persists.

5. Faulty 02 sensor(s)? Shouldn't I get a check engine light on? No... I've yet to get the CE light to come on..... which perplexes me more... shouldn't I get a CE light on for something that effects the car so greatly?

6. BAP Sencor? I don't even know what or where this is?

7. Wires and plugs.... again... low miles. Somebody did a dark hood test? What's that..... turn off all the lights and run the car hoping to find an arc jump?

8. TFI module.... again... .what and where is that?

Okay.... that's my effort thus far. I'm really hoping to get more feedback on this. Again, I will run the car to the store to see what code(s) it dumps. I'll cross my fingers it tells me whats wrong. But until then.... I wouldn't mind hearing some educated guesses.

thanks!!

 

[jrichker]

You are exactly correct. For as long as I've been playing with cars... I should expand my knowledge of the electrical workings. Problem is.... I'm lazy!! Really though.... I did look at your diagram as was going to try the jump diagram you attached. First thing I noticed was the single connector you have labled having a red/white wire isn't true in my case. My single connector has a tan/brown wire to it. The main connector does however have a red/white wire.

Then I looked at the whole thing again and my connector doesn't look anything like the one shown.

More reason why I'm a MECHANICAL designer.... not electrical.

I suppose I could simply drive the car to Autozone and let them plug it in. Hopefully the car won't die on me. I did get home tonight and started it up just fine with no issues. The pump primed well. I could faintly here the FP also while running. I didn't get the chance to drive it however.

It's just bugging me that the car is completely un-molested and now it's having this tricky little issue. I was hoping someone would read this thead and could relate to give me a direction to go on. It just seems weird that it's NEVER given my a problem until I did those burnouts. What could possibly have changed or got hurt??

Oh well.... off to Autozone when I get a chance. Thanks for your time.

All of the 5.0 Mustangs had the same wiring arrangement. If you see anything else, you are looking at the wrong connector, or someone has messed with the wiring of your car.

There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

 

[CornerCarvin67]

I went to Autozone for the codes the other day after I slid under and gave the filter a few whacks (just for the heck of it maybe stir it up a bit?? don't flame me for it). The guy came out and then asked me what year the car was. After I told him it was a 92' he said he couldn't help me. He said I should buy this $30 tool and count flashes. Although he did say because the engine light wasn't on it may just be a waste of money and time. I know I've read a few times this may not be true. The car drove fine the 10 miles there. So I made the decision there to skip the tool and based off of research on line and people I talked to.... I bought some fuel injector cleaner and a new filter.

I drove him with no problems at all, again.

I'm thinking I'll do the filter this weekend and cross my fingers. The other possible culprit which is free to check is the cap and rotor. If the problem continues maybe I'll buy the tool, use it... and then return it after I get the codes, if any. Hey, $30 is a half tank of gas these days!!

So that's where it's at for the moment...

 

[TomCat]

If it's 16 years old and only has 37k miles, maybe stale gas got your pump... mine sat for 1.5 years and when I decided to fire it up, it did, but only for about 3 minutes. It started bogging badly and eventually died. I went through all the checks and turns out the pump had actually died, so it's a definite possibility that yours is on its way out. You can pull the connector back at the pump and have someone flip the car on to see if it's getting the voltage to actually prime, too.
The fuel pump relay on our cars in strapped to the passenger-side fender apron near the shock tower. There are two, I believe it's the one closer to the front.
TFI is that little connector stuck on the side of your distributor. Kinda a faulty area for these cars, lol.
But yeah, I suggest trying what Jrich has listed for the codes. You never know what your car is trying to tell you lol.

Good luck, hope you find the culprit.

 

[LiquidGT]

I went to Autozone for the codes the other day after I slid under and gave the filter a few whacks (just for the heck of it maybe stir it up a bit?? don't flame me for it). The guy came out and then asked me what year the car was. After I told him it was a 92' he said he couldn't help me. He said I should buy this $30 tool and count flashes. Although he did say because the engine light wasn't on it may just be a waste of money and time. I know I've read a few times this may not be true. The car drove fine the 10 miles there. So I made the decision there to skip the tool and based off of research on line and people I talked to.... I bought some fuel injector cleaner and a new filter.

I drove him with no problems at all, again.

I'm thinking I'll do the filter this weekend and cross my fingers. The other possible culprit which is free to check is the cap and rotor. If the problem continues maybe I'll buy the tool, use it... and then return it after I get the codes, if any. Hey, $30 is a half tank of gas these days!!

So that's where it's at for the moment...

Yeah most Autozones can only test OBDII cars (96+), there is only one around here that can test older cars because they have the Superscanner.

You dont need a scanner for an OBDI Ford and the check engine light does not have to be on for codes to be present. All you need is a jumper wire or paper clip then you count the blinks on the check engine light. The procedure is here in the http://forums.stangnet.com/698148-help-me-create-surging-idle-checklist.html. Or Just look above for the procedure.

Tip: If you can, just record the blinking light sequence on your phone, then decipher it at your own leisure because you have the option to pause. When I blink I feel like I messed up.

 

[CornerCarvin67]

UPDATE:

I replaced the fuel filter the other morning. I've driven the car the last few days to work and haven't had the issue resurface. I'm hoping between the injector cleaner and the filter I may have netted the problem. I'll keep my fingers crossed.