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Discussion Starter #1
Okay. So a few years ago, i bought a used 1991 mustang 2.3 L that was in rough shape. After a while tinkering on it and trying to get it fixed up to be my daily driver (mainly because driving around a mini-van as a daily driver is not very....manly). So I fixed some wiring issues with the ignition system and the fuel pump, got and installed brand new coil-packs, plugs, and plug wires, starter and solenoid, belts and even the timing belt. And now after all that its backfiring like nobody's buisness, possibly missing (though its a little hard to tell through all the backfiring), and just in general running rough. The strange thing is, it seems to run fine when its in park/neutral, but when i switch it into Drive or Reverse or what-not, it starts running poorly. Any help is appreciated. Thanks in advance!
 

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Timing... all that sounds like a timing issue.
 

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it would be best to pull the codes from it. and agree with dbentesar, sounds like timing issue.
 

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Discussion Starter #4
I've checked the timing several times and it checked out fine. I pulled the codes and got:

121 closed throttle voltage higher or lower than expected
566 3/4 shift solenoid circuit failure
542 fuel pump secondary failure ECA to ground

then it repeated these 3 codes and then gave me these three:

125 TP sensor voltage lower than expected
218 loss of IDM signal; left side
332 insufficient EGR flow
and got 542 again

Also i took my DIS module to the local auto parts store and they tested it and they said it was bad.
 

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ok, the first thing i would check is the throttle sensor.
the first set of codes the eec outputs are active (happening right now), after they finnish repeating so that you can get them all, it outputs the codes that arent there right now but were a problem before.
the fact that the tp sensor in 2 different codes tells me that that needs checking. you can do it yourself, just google the site for one of the many good write-ups on it.
i would also double check the fuel pump wiring. make sure that a ground wire hasnt corroded off or gotten broken, loose, ect. and just triple check that you got all the wiring sorted out correctly. that system is full of wiring gremlins (=hidden problems) that are notorious for being tiny and giving owners fits trying to find them.:winks
for now, lets ignore the codes about the idm and the egr. the idm was most likely fixed when you put those new parts on it. the egr one might have been a fluke, or just a result of the running rough.
 

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Discussion Starter #6
I checked the TPS with a DVOM and it had the right voltage going to it (5v) and i checked the other pin and it checked out fine too. :/
 

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i would go thru everything with the fuel pump wiring again.
check the metal tube that goes out of the egr. the threads are reversed, lefty=tighty (at least on mine they are reversed). i used an abrasive rag wrapped around with tie wire to clean mine out. if theres a lot of carbon in it, you should probably replace the egr. i dont know of any way to test the egr tho, you can ask in a seperate thread if anyone here does.
 

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Discussion Starter #8
Thanks for the advice. I'll do that monday. Also, i replaced my DIS module with a brand new one and cleared up some wiring issues and it seems to be running great, except for the fact that the gas mileage seems to be kinda poor. I pulled the codes again yesterday and the only codes I got were
566: Fuel Pump Primary Circuit Failure
542: Fuel Pump Secondary Circuit Failure
and the second set of codes only had
332: insufficient EGR flow
and also code 542 again
When i've been driving it i noticed that it does seem to be shifing correctly despite the previous codes dealing with the shift solenoid. Could the EGR code affect the mileage? Like, last time I filled up it was about 20mpg.

And as for the Fuel Pump codes, I think i know why they are being thrown. A long time ago, I found that there was a short in the wiring for the FP or the relay was bad or something so I just wired it in (through the inertia switch) and just bypassed the bad wiring/relay.
 

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the egr being blocked will decrease your mileage, but not by nearly that much. you should be making about 26-30mpg (combined). most ppl with a stock setup get about 22-26 city/26-30 highway. unless youre doing nothing but city driving your mileage should be better than that.
i cant offer you much in the way of advice about the fuel pump wiring tho. you might want to start a new thread about it, since we've got a problem that your original thread title doesnt describe. it will be easier for you to get advice on what the deal with your fuel pump/wiring if ppl know that thats what the thread is about. i'm not trying to get on your case at all, a ton of threads wind up straying from their original title because one problem leads to another half the time, but i just want you to get the most help possible. for the guys with fuel pump knowledge to help you, they have to know that their knowledge is needed in a particular thread, and since we cant retitle our threads, its better sometimes to just start a new thread for a new problem.
as for your egr, double check that you have it hooked up to the vacuum lines correctly, and replace all the vacuum hoses for it. if that still doesnt help, then you will probably have to buy a new egr. :( you can always start a new thread asking if theres any way to test the egr, because i dont know of a way to test it, sorry.
 
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