Hey guys, for a few weeks now I have been having a problem with the 'Bird(HO conversion). Usually when it's cold, it will backfire slightly/misfire on other cylinders. I had AR133 plugs in it which I knew were too cold for this time of year, so I swapped the Autolite 25's back in. That helped but the problem still lingered, usually between 1500-2000rpm and approximately 20% throttle opening. I pulled the dist. cap off and noticed the rotor was cracked...new cap+rotor and a throttle body service later and it was running like new...for about an hour. So, I figured my wires were the next step..they were about 2yrs old and quite britle. The problem went away all together. About 300miles later it's back in action and worse than ever.
If I go full throttle from a dead stand still, it won't backfire or anything but just feels like it's tied to a tree until 3500rpm(like a 4cyl with nitrous...lol), it takes off like hell from there but now at about 4200-4600 it starts breaking up badly. It's definitely not valve float...And it doesn't exhibit these symtoms ALL the time...it happens often but isn't speed or temperature specific...I'm having a hard time diagnosing it simply because there really is no patterned failures.
Any experienced advice would be welcomed
Thanks and Merry Christmas,
Don
hey sick, whats the specs on the engine, size, type of asperation, etc?
It's an internally stock '91 HO motor, no power adders. It almost seems like it's not getting enough voltage to the ignition...like an MSD 6 getting only 11 volts...lol.
any engine codes?
Any codes?
Sounds like a bad coil or a connection at the coil. Somewhat like a surging problem, right?
James
but also the tfi could be at fault too. but im not 100% on that.
i never had a tfi kinda go bad, im one of the lucly ones that my mustang died in an intersection, could be a coil, try changing your fuel filter to and maybe checking the fuel pressure
I did the fuel filter a few months ago, the fuel pressure is fine(I have a rail mounted pressure gauge) and I just replaced the coil last night...didn't do any good. The car has always had a little idle surge to it. Friday I might try doing the TFI module and the pick-up coil inside the distributor. I already checked the distributor shaft for excessive play, but it was tight.
On the way home from work tonight it ran like until I was about 2minutes from home...I was at a light and stomped on it when it went green(was expecting to accelerate at a 3.8L's pace) and ended up getting wheels, so I stayed on it and barked the tires going into 2nd gear. I don't understand it. I'm also thinking the EEC relay could be a part of the problem...well the wiring/connections anyway. I'll have to try to locate that just to see if the wiring is good and the connector isn't corroded or anything.
I know this has to be electrical. I just want to find it the right way rather than the "Dart-board Diagnostics" way.
Thanks Again,
Don
hello,
I had the EXACT same problem with my '89 GT that I have with a 331. When I first got it running everything was cool until a month went by. To get to the chase It ran like , bucked, stalled, poor power, ghost check engine light etc. But, also only some times. What I ended up doing was on EVERY engine connector I used ford di-electric grease. On the two big cylinder electrical plugs by the throttle body. I used fine grit sand paper and made little rolls and sanded all of the male connectors, then used the grease. I took of the TFI module and put new grease behind that and of course on the connector. I'm not joking, after that it was a totally different animal. I would say that 95% of the problems have yet to return. Give it a try! Good luck
I just pulled codes tonight. KOER tests, came up with a 33 and a 92. The 33 has to do with the EGR position sensor showing little or no activity...I'll have to clean my EGR and see what happens. The 92 is showing that the left bank O2 sensor is sending a signal over .5 volts all the time...that's showing super fat rich...but it's not running rich anywhere. The O2 sensor is only like 2 or 3 yrs old but I'll have to check on that also.
On the way home from work tonight, it ran like the usual for about 5mins...the rest of the 15min ride, it was running like a raped ape. Seems like it's getting better...knock on wood. Now I was running colder AR133 plugs until just recently...they dont' work out too well in cold weather...I guess it's possible that they caused the O2 sensor to foul. I plan on disconnecting the battery to clear the codes...drive it to work tomorrow and check the codes again. I'll post back tomorrow night to let you know my results.
Okay, didn't get a chance to do anything I said I was going to...ed rain. From my understanding, over filling the gas tank can cause the charcoal canister to fill with liquid fuel...thus causing the code 92. Which almost makes sense being as they always crank an extra dollar worth of gas into my tank after it stops...even though I tell them not to...that and my problem started right after I filled up there for the first time. I don't know...too many variables. The weather should be decent tomorrow...so I'll check my O2 sensor...check my EGR and EVP sensor, the EGR vacuum solenoid as well as the charcoal canister and purge valve...hopefully I come up with something.
-Don
Well, I replaced the oxygen sensor in the left bank today...runs great below 4000rpm now. I also removed my EGR valve only to find little balls of carbon all stacked up on the EGR valve pintle. I replaced that valve with a significantly cleaner one and the problem is still there. I drove it up to work and pulled the codes again, this time a 44 and a 34. The 44 has to do with the thermactor bull...I kind of expect to see that code, being as I have the smog system gutted. The 34 was showing as low EGR flow and/or EVP out of range...according to the manual, if I plugged the EGR vacuum supply hose and ran the test again and still got a code 34, that it was most likely the vacuum solenoid...as luck would have it, the code 34 came back. I will pick up the solenoid tomorrow and hopefully have it on tomorrow or Sunday, weather permitting. I'll keep you guys posted.
Thanks,
Don
Well, it's still breaking up a little bit even after replacing the EGR vacuum control solenoid. I want to know why the hell all those vacuum lines run behind the fender...that just seems silly to me...is there a vacuum canister there or something? My next step is to test the EVP sensor(although I'm not so sure that's the cause).
When free-revving, after I let off, at around 4500rpm or so, the tach will jump around just for a millisecond...that's what still leads me to believe it's the pick-up coil or tfi module...being as that's what does the primary side switching of the coil. I guess I'll have to start testing . It would be nice if it wasn't raining so much.
Well, I dumped some Lucas fuel injector cleaner in the car yesterday with a full tank of gas. After letting it warm up and driving for a few miles it was running great. Drove about 200miles today and it's still running like a bat out of hell...maybe I had some deposits in the injectors? Oh well, as long as my problem stays away, I'll be happy. Thanks to everyone for their advice, opinions, and suggestions!!!
You gutted the smog system but you're only getting a 44, and not a 44/94? That is very odd.
Yeah, I just recently started getting the 94 also...like I said, about 8 codes stored in there total right now...gotta check my TPS too. Little bit at a time.
i've got a question,
did you happen to do a throttle body cleaning on your rig some time ?!
if you did..and didn't use the right stuff, i may have taken out your
O2, or, it could have been bad from the begining,
i know at my shop, we've got a computer that will read the values of the O2 sensor while the motor is running, try that...most the time they want a diagnostics fee,
if you haden't done a TB cleaning, maybe try that,
it might help if i read the rest of the post where you fixed it ..and didn't need any advice,
5.0's aren't all that hard to pull the injectors off of are they ?! take them to an ultrasonic cleaning place, and have them flowed an all.
maybe check the fuel pressure, make sure your FP is keeping up
(am i still talking ? )
No, but pulling all the other out of the way is a pain in the ass!
Yeah, I did do a throttle body service to it...used STP Throttle Body and Air Intake Cleaner...I used some carb cleaner before that. That actually took the high rpm miss away for about 2hrs then it would come back....The injectors came off of my buddy's 12.70 'Stang before he upgraded to 24's. The only thing I can think is that maybe some of the pintle caps broke off of the injectors and either the spray pattern sucks or there is building up on the injectors from it not running right. It's running pretty good now, we'll see how it goes from there. Maybe a couple more bottles of Lucas fuel injector cleaner will do the trick...lol. Once I save up a little money, I'll get a new EGR and EVP sensor...I don't think they are the root of the problem but they need to be replaced.
Thanks again,
Don