Sporadic Check Engine

[Jersey Fred]

I just bought another '93 ATX as a winter car with 120K on it (i.e. I knew it needed some work). The check engine light comes on ONLY after taching it up over 5 grand or so. Most days I can drive it hundreds of miles with no check engine light; other times all it takes is one heavy-footed accelleration to bring it on. I checked the codes with a Ford code reader and it only referenced a 'cooling system out of range' error. I will replace the thermostat on Saturday but this problem sounds more like an O2 sensor (?) Is it possible that after revving above 5K or 6K that I am aspirating cat dust onto the O2 sensor???

fred? sd?

 

[DougLee25]

There is a temperature sending unit on the right hand side of the thermostat (not the temp sending unit for the dash on the left side) that sends a signal to the computer as to whether or not the engine is up to operating temperature. This will send the computer into closed loop. This could be faulty. Is your temp according to your dash gauge coming up to normal? What kind of mileage are you getting?

~Doug

 

[Jersey Fred]

Temp rises a little slowly into normal range and stays there (no fluctautions). I dont think that the temp rises significantly during hard accelleration although I dont usually stare at the guage (i will now). Also mileage is normal - 16-21mph.

 

[DougLee25]

Hmmm.... Well I don't think it could be your temp sending sensor. Mileage seems normal, the gauge reading in the car seems normal.... I would clear the codes and drive it some more and see if the code comes again. What is the exact number the code reader is giving you? I have not heard it called a "cooling out of range before"??

 

[1fastsho]

Sounds like the ECT; it's on the right side of the upper radiator hose spout. Even though it warms up normal and runs ok, it still could be out of spec just enough to throw a code. Also check the EGR passages inside the intake(open the throttle body plate to see them) there should be 4 holes back there, the lower ones are for the EGR and usually get clogged up. This happens a lot on the ATX cars. You have to manually clean it out, just spraying it with throttle body cleaner won't usually do it.

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Shawn Pasley
Innovative Performance Technologies
770-725-4631 www.iptech.tv
92 SHO red/grey
3.2L(bored) Lowered compression(9:1)
stageII cams, Ported/Polished heads,Ported/polished Intake manifold(runners, endtanks, and behind the throttle body), big bore butterflies,80mm maf, LPM,equal length Long Tube Headers and custom Y pipe, Dynomax cat-back, Koni/coil-over suspension, poly-bushings everywhere,26mm FRONT sway bar, 28mm REAR sway bar,rear strut tower brace, solid subframe bushings,subframe connectors, tubular aluminum adjustable rear control arms,shortened shifter,235/45/17 Toyo Proxes T1-S's on TSW VX-1's. 15 lbs of boost here I come!

[This message has been edited by 1fastsho (edited 01-08-2002).]

 

[Jersey Fred]

Doug - I dont remember the exact codes from two weeks ago and I haven't had a chance to re-run the codes (left code reader in MD); I'll have to set up some wires to check the codes using the CE light tonight. I know the coolant reservoir runs dry slowly and the radiator is leaking under pressure but it is full whenever I pop the rad cap so I wasn't too concerned about the cooling system code. I did reset the codes but I am sure that they have reappeared by now (CE has been on a dozen times since then).

Shawn - bad sensor / clogged intakes sounds likely. I'll give it a shot this weekend when I have some time to mess with it.

Thanks guys.

 

[Jersey Fred]

Follow up -

Good call on the EGR jets Shawn. I was surprised because EEC was not throwing a 332 code but CE light is gone now that I cleaned them. New codes appeared for the RH HEGO so looks like I will be replacing both sensors along with t-stat on Saturday.

Also, new code for "Cannister Purge 1 Solenoid failure" and I'm not sure where to locate CANP solenoid. ANy advice?

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