I have A problem with my Camaro -87, 305 TPI. When I'm standig still with the gearbox in Drive it idles fine but suddenly it stalls. It seems like it only happens when the engine is warm because I can drive for about 20 minutes with no problem. When this happens I get a code 33 from the SES.
I have changed the MAF and it's relays, the IAC and even the oilpressure sensor (read somewere that it could affect the MAF). I have also adjusted the IAC and TPS several times.
This problem starts to get on my nerves.
Anyone with some ideas what to do?

regards

Hans Axelsten, Sweden

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Camaro IrocZ -87
305 TPI

It might be your oil pressure sending unit. When the oil pressure drops bellow 30 psi your computer will shut off. Also Check to make sure your idol isn't to low.

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84 Z28
406
accel supper ram
6000 rpm Hyd roller cam
afr heads
t-56 trans
9" ME rearend

I have the exact same problem in my '88

I have noticed, too, that it only happens when the oil pressure dips down.

Where is the sensor located. Thanks.

It is located next to the distributor screwed in behind the intake manifold.

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84 Z28
406
accel supper ram
6000 rpm Hyd roller cam
afr heads
t-56 trans
9" ME rearend 3.91 Gears

I have tried to change the oilpreassure unit but it made no difference. Could it be the Spark Control Module and is there a way to check if this is working?

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Camaro IrocZ -87
305 TPI

What you need to do is get a spark checker. If you get plenty of spark. I would check into other things like your spark plugs, TPS,or your fuel system.

The oil pressure sensor does NOT turn off the fuel pump. It is a back-up power supply for the fuel pump. In the event the FP relay fails, the sensor will turn on the pump when pressure gets to a certain point. (not sure what the exact pressure is, could be as low as 5psi...) So, if your fuel pump realy is toast, and your oil pressure is really low, this may cause a problem. If, however, your FP relay works fine, (test by turning key to "on", pump should run for two seconds) and you are still seeing this problem, you need to find the real cause....

Personally, I find chasing these problems can be very frustrating, and time consuming. Check the easy stuff first, then start working toward the more complicated (read "expensive") stuff.

A service manual is a god send.....

id make sure all your connections to your maf, and maf relays are tight and CLEAN , also make sure you have no vacuum leaks anywhere in the air tubing.. do this before you spend anymore money.

I fixed the problem. A few weeks ago I bought a new TPS sensor but I did not change right away. This weekend I finaly got time to do that and it solved the problem.
But there is still one thing that I dont know if it is right. When I adjusted the Idle with the IAC disconnected I had to adjust the screw all the way in, otherwise it wont idle when the gearbox is in drive. Now when i start the engine when it is cold the RPM goes up to about 2000 and then slowly drops to normal idle. Is this normal or is there still some problem?


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Camaro IrocZ -87
305 TPI

When you changed your TPS, did you follow the IAC adjustment procedure outlined in the Technical Article Section? If not, you need to. You will have do this anytime you change something to do with the TPS, to get the idle adjusted correctly.



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Mike Metzler (Desert86Roc)[*] Webmaster: SpeedWorldMotorplex.com[*] Click Here For 86 IROC 305 TPI (406 build in progress) Page

ET's @ 1250 ft[*] 14.28 @ 95.461 mph (uncorrected, NOS, no headers)[*] 15.365 @ 86.785 mph (uncorrected, headers, no NOS)
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