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Discussion Starter #1
I'm trying to correct a low boost issue with my 1997 Esprit. Everything seems to check out, yet I only ever get wastegate boost pressure form the car in all scenarios. All gears, cold, hot doesn't seem to matter. I only get about .25 - .35 bar of boost. I want to try replacing the wastegate control solenoid and since it appears to be a GM part I wanted to know if anyone has a cross reference number for it. The part is listed on the cross reference spread sheet, but it indicates it was a 'Lotus factory' only and I can't find that Delco part number anywhere. I see other valves that look similar, but they only have two ports on them. The one I pulled from my car has three. I don't know if it has a norm. open / norm. closed port. I also saw somewhere that the third port is the 'vent' port and should have a small filter (piece of foam) over it. Mine does not have said filter.
I took mine out and was able to blow through the port if I energized it, but it seemed 'sticky'. I cleaned it out with some carb cleaner and that seemed to help, but still low boost. We have also disconnected the wastegate control and we do get overboost in doing so, which tells me that turbos are building boost fine (like a scalded cat!!), but something in the control system isn't working properly. There isn't much in that system so the obvious thing to try is the WG solenoid. Just need to find one.
 

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There’s a spring kit that you order separately that gives you a bunch of different springs for the wastegate, you have to ask for that if you wanna play with different spring options. Otherwise I think it does come with lightest close to stock spring.
 

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There are other possibilities that can cause low boost pressure. A leak in the induction system is the most likely. The other thing I would check is there is a procedure where you pressurize the actuator to a specific pressure to move the rod. You can also have a leak in the line to the actuator. Refer to EMM.3-U Turbo Boost Control for more information.
David Teitelbaum
 

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Discussion Starter #6
Wastegate actuators seem to be fine as we can disable boost control and the thing boosts like a scalded cat. So I think that's all good as I just had the turbos rebuilt. The solenoid that I have has 3 ports on it. Most of the ones I can find that look similar have two ports. I'm not even sure I have the correct solenoid as the part number on mine (Delco 1947266) doesn't match the part number from the cross reference sheet (Delco 1849138). I can't find either of these anywhere so I'm not sure what the stock one looks like. If I can't find one of these simple solenoids I will look at an aftermarket one, but I would rather just keep it stock if possible.
 

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Similar 3-port with different mount-

Another option, used as supercharger wastegate valve, aka 199-7244-
1258071


Just going on visuals here, I have no idea what the coil / connector specs are on these or if they will work. Buick Riviera with supercharger fitment
 

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Discussion Starter #8
Looks like JAE to the rescue. They found a few in Belgium and snap them up. I'll give that a try see what I find out.
 

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Most of the turbo electronics are similar to a 1988 - 1990 Pontiac Sunbird GT 2.0L turbo. The map sensor and the wastegate control are all the same.
 

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Discussion Starter #12
The 214474 has only two ports on it, mine has 3 ports and the mount is different (other side compared to the one I have). I'm sure it was just some crap GM part that they found and then tried to make it exclusive to Lotus to bump the price. Just don't know which one. I'll give the one from JAE a try, it's a three port and I will use the bracket off the one I have.
 

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The 214-474 I linked to has three ports, one just has the foam sock covering the "vent" port. Still can't say if it's more than just a look alike with a different bracket. Glad JAE had the real deal, I'd seen somewhere they were not available.
 
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