1997 drivability issues

[missinglinc]

I bought this 1997 Bird in July of 2023 as a non runner, determined the PCM to be bad, also replaced the fuel pump, plugs, wires, and both coil packs.

It has been running since then, been my very reliable daily driver, but still has some issues, namely idling fast, and poor acceleration. When I cold start it, it will fire up immediately and runs at about 1100-1200 rpm, in park, and about 950 -1000 rpm in gear, this does not seem to change until after 20 minutes or more of driving, (my commute to work is seldom longer than 10 minutes). The other concern I have is that it seems like it doesn't want to rev past about 3800 rpm in first gear when I floor the accelerator, it's as is if it has a rev limiter, yet in second gear it will pull hard, no problem. This seems to be an intermittent issue as sometimes it will pull to redline in first gear without issue. It also seems a bit sluggish when I hit the throttle hard from a stop, it seldom will spin the tires, just kind of bogs until 2000 rpm, then it starts to pick up and pull harder.
One other issue I have experienced in the past after a long run on the highway, (2 to 3 hours or more) was a rough idle and stink of raw fuel, I thought the first time that I may have gotten some bad fuel on my trip, but it happened again after running the tank to near empty. This has not happened recently, however I have not taken it on any highway trips for a while. The car has about 125,000 miles on it presently and as mentioned is my daily driver, I also have a 1989 Thunderbird Super Coupe, recently inherited, with about 65,000 miles, and have previously owned several 83 to 88 Thunderbirds and Cougars, and a 92, 93, and 94 Thunderbirds.

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[Alex]

Ik kocht deze Bird uit 1997 in juli 2023 als een non-runner en stelde vast dat de PCM defect was. Ik heb ook de brandstofpomp, bougies, kabels en beide bobines vervangen.

Hij rijdt sindsdien als een zeer betrouwbare dagelijkse auto, maar heeft nog steeds wat problemen, namelijk een te snelle stationairloop en een slechte acceleratie. Als ik hem koud start, slaat hij meteen aan en draait hij ongeveer 1100-1200 tpm in de parkeerstand, en ongeveer 950-1000 tpm in de versnelling. Dit lijkt pas te veranderen na 20 minuten of meer rijden (mijn woon-werkverkeer duurt zelden langer dan 10 minuten). Mijn andere zorg is dat hij in de eerste versnelling niet verder wil komen dan ongeveer 3800 tpm als ik het gaspedaal helemaal intrap. Het lijkt alsof hij een toerentalbegrenzer heeft, maar in de tweede versnelling trekt hij gewoon hard, zonder problemen. Dit lijkt een incidenteel probleem te zijn, want soms trekt hij in de eerste versnelling zonder problemen tot aan de rode lijn. Ook als ik vanuit stilstand vol gas geef, lijkt de auto wat traag te zijn. De banden spinnen zelden, maar het blijft een beetje hangen tot 2000 toeren per minuut. Dan begint de auto op te pakken en harder te trekken.
Een ander probleem dat ik in het verleden heb ervaren na een lange rit op de snelweg (2 tot 3 uur of langer) was een onregelmatige stationairloop en de stank van rauwe brandstof. Ik dacht eerst dat ik misschien slechte brandstof had getankt tijdens mijn rit, maar het gebeurde opnieuw nadat de tank bijna leeg was. Dit is de laatste tijd niet gebeurd, maar ik heb er al een tijdje niet meer mee op snelwegritten gereden. De auto heeft momenteel ongeveer 200.000 kilometer op de teller en zoals gezegd is het mijn dagelijkse auto. Ik heb ook een Thunderbird Super Coupe uit 1989, onlangs geërfd, met ongeveer 105.000 kilometer op de teller, en heb eerder verschillende Thunderbirds en Cougars uit 1983 tot 1988 gehad, en een Thunderbird uit 1992, 1993 en 1994.

Beste, heb je de storingscodes uitgelezen?
Alex

 

[mcm51]

Consider PCM, IAC, TPS or mass-air sensor....................

 

[missinglinc]

Consider PCM, IAC, TPS or mass-air sensor....................

Would any of these trigger a CEL and a code? The CEL is not on, but I haven't put my code reader on it lately.

 

[Alex]

Of corse, it can be a oxygensensor

 

[mcm51]

@missinglinc , yes they would but that would be after your sitting on the side of the road, As your going thru these issues, maybe you should check codes after every time you take the Bird out, now as far as the rev's stopping at 3800 in first gear, I'd be leaning toward tps and/or pcm,..............After a long trip and she has a rough idle and the smell of fuel, to me that's either pcm, mass-air or o2's...........
Imo, if you've never swapped out the tps, or mass-air, or even all o2's, at least the front one, you should............When it comes to a pcm, it's one very important part, my oem pcm did all kinds of strange stuff as it was failing, you can have all the great sensors ya want, but if the pcm don't know what to do with that info, it's all useless...............
On the idle issue, pcm or iac.........
On the rough idle/smell of fuel, pcm, mass-air, upstream o2's
On the not reving past 3800, pcm, tps

 

[missinglinc]

I put my code reader on it after work today and got P0172, bank 1 system too rich, P0175, bank 2 system too rich, and P1443, evaporative emission system control valve low/no flow. I have tried changing the tps before and no change, put the original back in. I've also replaced one of the O2 sensors due to a burned/melted wire harness.

 

[mcm51]

@missinglinc , On that 1443 code, I can't help you with that one, I believe that has to do with your charcoal box located down under the air filter box, I can't help there because the pcm only started watching that on a '96-'97 Bird, but I believe there's 2 or 3 coming off it that over time can rub up against some or even get a crack in them and would show up as either low/no flow, and over the years I noticed that if this happens, the break or rub thru is always near the charcoal box so you probably don't have to check those lines all the way back to the motor, just the first foot or two coming off that box.....Now I have no ideal how the pcm is watching that box, it may have a sensor plugged into it or maybe something that's spliced in to one of those lines itself, see mines a '95 and my charcoal box still looks like they did back in the '80's............................
Now on those two rich codes, that could be mass-air sensor, it works with the pcm for setting air-fuel mixture, or wacked out o2's that could play with air/fuel mixture upstream, so if either one of those is failing or faulty, it could give a rich/lean code, now this is assuming that there's not any problem with a fuel injector itself, like hanging open, consider how many miles are on those injectors ? you might want to try the cheapest mass-air you can find like rockauto to eliminate that sensor, and consider changing the other upstream o2, upstream is the one's really watching air/fuel mixture, the downstream's are really just checking the upstreams.....

@Alex, yes a faulty o2 can cause rough idle and most of the time bad OR great fuel mileage, you've got to have good working o2's to get a good air/fuel mixture, assuming that everything upstream of that o2(injector, mass-air, pcm) is working proper,,,,,,,,,,,,

 

[missinglinc]

I was able to spend some time yesterday and took the maf sensor out, thoroughly cleaned it and reinstalled it. I also replaced the tps then cleared the codes from the pcm, and fired it up. Idle speed was down to 790 to 820 RPM in neutral, and about 550 in drive. Then I took it out for a road test, it was running excellent, smooth, lots of power again. Seems like all problems are resolved since when I checked for codes again after the road test it was clear.

 

[mcm51]

Always nice to hear good news, I'd check those codes again after about 100 miles of driving.......The only negative thing I can say is, that idle sounds a little on the low side, I'm looking for 900-1200 on a stone cold start, and about 600-650 in gear on a warm motor, but your numbers may change a little as the pcm dials in some more, after all you've been thru getting this Bird to were your at, it's time to take a breath and have a little victory party........If you can run the next 100 miles with no codes, I think your on your way.......

 

[Alex]

Ik heb gisteren wat tijd vrij kunnen maken en de luchtmassameter eruit gehaald, grondig schoongemaakt en opnieuw geïnstalleerd. Ik heb ook de oliekeerring vervangen, de codes van de pcm gewist en de motor gestart. Het stationair toerental was gedaald tot 790 tot 820 tpm in neutraal en ongeveer 550 tpm in de drive. Daarna heb ik een proefrit gemaakt en hij liep weer uitstekend, soepel en had veel vermogen. Het lijkt erop dat alle problemen zijn opgelost, want toen ik na de proefrit opnieuw op de codes controleerde, waren ze weer in orde.

Een veel voorkomende kleinigheid