Digital EGR Test?

[Kennetho]

95 Beretta 3100. Is there a way to test the digital EGR's (3 solonoids)? I'm having 2 and 3 fail. Mainly getting off the highway or speeds above 60 with quick decelerations. Hate seeing the engine lights. Would love to know if they can be ohm checked or a some similar way. Would be great to get one at the gy for 20$ than 100$ at rockauto for something not so important.

Also, is it possible to switch to the 96+ tube like ones? Plan on doing a 3400 swap between summer and fall and would be nice if it was possible so I could save a little by not getting the adapter and getting maybe a cai or something else instead.

Thanks.

[86FieroSEv6]

It is possible to physically fire the solenoids individually by using a pair of jumper wires. Usually I will raid an old GM connector with several inches of harness attached to make a test connector. Then, using the connector diagram, I clip a fused wire to battery and the 12v pin at the valve. Next, individually but momentarily touch each of the other solenoid pins to ground and listen for a distinct "click" sound. Quickly and repeatedly brush the ground test connection because sometimes the solenoid will only stick as it warms up and cycles repeatedly. Mind you, this will only physically test the EGR itself and is not 100%. Based on your description, carbon buildup mixed with a little oil blowby is probably causing your EGR to have flow errors even if it isn't sticking. The thing to remember is that there is the possibility that one or more drivers have failed in the PCM as well. The PCM is actually watching the MAP sensor during EGR diagnostics. When test conditions are met, the PCM fires each solenoid in sequence, looking for a corresponding change in MAP value. When doing the dynamic test of the valve as described above, you can do it with the engine running warmed up at idle and note whether or not the engine stumbles as you fire each solenoid. They are each a different orifice size and the engine should react accordingly i.e. stumble worse for the large opening. Some aftermarket exhaust systems can cause false errors even when the valve is working fine.

[robertisaar]

using the stock PCM, no you cannot run the linear EGR, you're stuck with the digital setup.

and this should help.



86FieroSEv6: i did the same thing and marked the wires accordingly. i crimped on some spade connectors to the ends of the 4 wires, so now all i have to do is connect to +12V and ground with jumpers and it works damn well.

[Azrael]

If each valve makes a good 'click' when you apply a voltage across it, my guess is that the passage from the valve to the intake manifold is partially plugged with exhaust gunk. It's a common problem. Some time, coat-hanger wire, a shop vac and carb cleaner can help clear most of it out. You can also disassemble the EGR to clean the individual valves if you really wanted to.

You can't switch to the 96+, linear EGR without swapping to an OBD2 computer. The newer one is based on a stepper motor while the digital uses solenoids.

[Kennetho]

Thanks. I'll give it a try.

[mfewtrail]

Here's an article about testing the older digital egrs: http://www.wellsmfgcorp.com/pdf/Counterpoint3_4.pdf