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Old 05-26-2003, 05:05 AM   #11
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DAAAAAAAAAAAYEM I'm getting closer but not there yet! fryed my second computer! it turns out one of my rad fans(passenger side) was fryed . so i'm guessing it was sending a spike back to the computer and damaging it. the code that was coming up and still is, was QDM - 1. ( QUAD MODUAL-1 ) . So anyways , i replaced the fan , and they both seem to be working fine now. ( was burning alot of fan fuses before) .
Now. the hesitation problem is still there. the more the engine gets hotter , the worse . i still have the computer to change ,now that i think it'* safe to , since i had the initial problem fixed . but what the hell could it be other than that? it runs 100% when the engine is cold, and as soon as it gets hot i get that hesitation ??
any help would be appreciated.
thnx
Al
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Old 05-26-2003, 10:05 PM   #12
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If I understand this correctly, you didn't have a problem before the MAF screen was removed? And you reset the computer obviously. How many miles have you driven since then? It can take up to 100 miles for the PCM to 're-learn' that the MAF screen has been put back in.

If the MAF sensor itself suffered some damage after the screen was removed, it could be causing your problem as well. If it'* not reading correctly, your air/fuel ratio will be off (either lean or rich), causing some of your problem. As the intake air gets hotter, the density goes down......and you tend to run rich. Rich can cause a loss of power just like lean can.


There really are alot of contributors and possibilities here.

Can you give us a brief rundown on everything that'* been done to the car in the last 6 months? (including tuneup items)????
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Old 05-26-2003, 10:56 PM   #13
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i thought that the exposed wire on the MAF was a temp sensative wire. the cooler it got, meant that the more air that was crossing it and making it cooler, then in turn , richening up the mixture due to the increase air flow.
i may be wrong, and if i am , im sorry, but that is my aspect on the way the MAF works
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Old 05-27-2003, 12:09 AM   #14
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Quote:
Burgundy_Boat wrote:
bonnycrazy wrote:
took the negative terminal off for about 15 mins , still got the problem , when my engine gets hot it starts cutting out between 4000-5000 rpm ( in all gears ). my ( service engine soon) light is on, so i had it scanned and they said that my computer was fryed??
any suggestions?
Thnx
Al


how do you get to 4000-5000 RPM in 4th gear??? i wanna know so i can do it, cause i can't right now


it would take a heavy foot and a loooooooong stretch of road !
Except there is a governor at 128mph. Then top speed would be achieved in 3rd gear because there is not enough power in 4th. Theoretical Top Speed is 255, so 5 grand in 4th would be lie 230 or 240, but top speed is achieved at redline in 3rd, which is somewhere between 160 and 170. If you got your governor removed and you are making enough power to overcome the drag you could do at least 160 in 3rd. 4th would slow you down. But seriously, I think they were just trying to say that at 4-5K in 1st and second it would cut out.
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Old 05-27-2003, 02:11 AM   #15
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The IAT measures temp. The MAF detects DEFLECTION of the wire.
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Old 05-27-2003, 03:20 AM   #16
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Quote:
Originally Posted by willwren
If I understand this correctly, you didn't have a problem before the MAF screen was removed? And you reset the computer obviously. How many miles have you driven since then? It can take up to 100 miles for the PCM to 're-learn' that the MAF screen has been put back in.

If the MAF sensor itself suffered some damage after the screen was removed, it could be causing your problem as well. If it'* not reading correctly, your air/fuel ratio will be off (either lean or rich), causing some of your problem. As the intake air gets hotter, the density goes down......and you tend to run rich. Rich can cause a loss of power just like lean can.


There really are alot of contributors and possibilities here.

Can you give us a brief rundown on everything that'* been done to the car in the last 6 months? (including tuneup items)????
well, here we go!
bosch (oem) o2 sensor , mobil 1 oil change , oil filter , fuel filter , ngk irridium spark plugs, bosch plug wires, accel coils , pcv valve , removed cat, flowmaster 80 series exhaust,been using nothig but 92 octane since i bought the car.
Now, we ran another scan on the car and it was reading code(P1640)=(qdm-1) again! mind u this is the second computer. i think the quad # 1 was not fryed in either computer ,it was just failing . now, quad #1 controlls three devices :
1) boost control.
2)evap canister purge.
3)*** TCC APPLY. ( this is my main problem)
now , the (TCC APPLY) would be my torque converter slipping .

when i washed my engine, i think moisture built up in the passenger side fan'* plug, and fryed the fan causing a short. it turnes out that the fuse block containg the fuse for the fan is connected to (quad#1). but the messed up thing is that i replaced the fan moter, so that fixed that problem. but there has to be a short somewhere that was caused by the fan going.( i think). so this narrows it down to a short within the three devices that are controlled by ( quad #1).
Or do u think that one of these three devices are fryed ?? they are solenoids mind u.
1)boost control solenoid.
2)evap purge solenoid.
3)tcc apply solenoid, wich would be right inside the transaxle.

are they likely to go easy??

any suggestions?
Al
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Old 05-27-2003, 08:48 AM   #17
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hope this explains how a MAF work

There are two common designs of MAF sensors used in today'* vehicles. One produces a variable voltage output (analog) and the other produces a frequency output (digital). In either case their operation is similar. Both outputs can be measured by a scanner or a digital volt/ohm meter (dvom) that can measure frequency.

Both designs work on the "hot wire" principle. Here'* how they work. A constant voltage is applied to the heated film or heated wire. This film or wire is positioned in the air stream or in an air flow sampling channel and is heated by the electrical current that the voltage produces. As air flows across it, it cools down. The heated wire or film is a positive temperature coefficient (ptc) resistor. This means that it'* resistance drops when it'* temperature drops. The drop in resistance allows more current to flow through it in order to maintain the programmed temperature. This current is changed to a frequency or a voltage which is sent to the computer and interpreted as air flow. Adjustments for air temperature and humidity are taken into consideration since they also affect the temperature of the heated wire or film.

wire deviation has nothing to do with it, it is a heated wire that cools by the airflow over it,the cooler it gets, the more air that is coming into the engine.
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Old 05-27-2003, 02:43 PM   #18
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Crazy, change that O2 sensor to an AC Delco. I'd say plug wires also need to be changed. I don't trust Bosch wires any more than bosch plugs. Jr had a set prematurely fail. They weren't designed for our cars.

Also, when you determined the QDM1 fault, was your foot on the brake pedal? My scantool does that.....so does Jr'*. It'* a programming fault in our scanners. If your foot isn't on the brake, it'll read good.

If that isn't the case, the Quad modules (both of them) are in the PCM. Did you just replace the chip, or the whole PCM?

As far as the 3 solonoids you're talking about, you can easily check them with or without a scantool. Simply ground one pin, and run a hot wire from the battery to the other pin, and see if they actuate.

The scantool will tell you everything you need to know about the TCC.
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Old 05-28-2003, 01:23 AM   #19
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will , i just changed the o2 sensor again. this time i got the AC DELCO . still got the problem but it'* getting worse it kinda feels like my fuel pump is failing ??
cause when u let it cool down a bit it runs a little better, when it warms up again it starts cutting out. and when i did the scan my foot was off the brake pedal and everything was off exept the ignition.
i'll tell u it'* starting to drive me nuts but i'll never give up
one more thing i'd like to add. do u think it could be my IAT sensor? do u think i damaged it when installing my CAI? i located the IAT right before my TB . do u think i should have it right after my TB ? grrrrrrrr , this is starting to confuse me ! but i'll nail that problem sooner or later
untill then , keep in touch
Al
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Old 05-28-2003, 01:31 AM   #20
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Shooting in the dark here somewhat....if your IAT was bad, you'd have an SES light, or at least a code. Forget that.

If it'* getting worse, I'd try a real cheap fix. Get a can or two of intake safe cleaner, an old toothbrush, and a new TB gasket. Remove the MAF sensor first, and GO TO TOWN on that TB.

Either before or after that, get a pressure gauge on the fuel rail. Check it with the ignition on, engine off, and the engine on. Get back to us with the pressure readings. A local mechanic should charge very little for this.
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