84 TBI rebuild

[Tom1]

Just want to thank everyone for their suggestions so far. I have purchased the TBI service kit (new gaskets, etc.) because I just wanted to see what was inside these units and make sure they were as they should be since I bought the car used with several thousand miles. Anyway during this process I noticed that the fuel regulator on the rear TBI unit (drivers side) has a small threaded bolt which is used to adjust the position of the spring. Well since I did not know exactly what I was doing I accidently turned this adjustment bolt and now don't know where to reset it. The instructions that came with the rebuild kit says this is set at the factory and not to mess with it. Does anyone know what I am talking about and how I can reset this adjustment? If so I would be most appreciative for any help. - See more at: http://www.corvetteactioncenter.com...corvette-warm-start.html#sthash.HFNekyJ3.dpuf

 

[Tom1]

Just want to thank everyone for their suggestions so far. I have purchased the TBI service kit (new gaskets, etc.) because I just wanted to see what was inside these units and make sure they were as they should be since I bought the car used with several thousand miles. Anyway during this process I noticed that the fuel regulator on the rear TBI unit (drivers side) has a small threaded bolt which is used to adjust the position of the spring. Well since I did not know exactly what I was doing I accidently turned this adjustment bolt and now don't know where to reset it. The instructions that came with the rebuild kit says this is set at the factory and not to mess with it. Does anyone know what I am talking about and how I can reset this adjustment? If so I would be most appreciative for any help.[/QU

Come on you Crossfire fans! I'm sure someone out there has rebuilt these TBI units. These regulators are real simple inside there are only four parts, diaphragm, adjustment screw or bolt, a cone shaped cup and a large spring. All the shop manuals I have say not to take them apart because of the large spring pressure and you could get hurt if the spring jumps out, but I did not find this a problem. I was careful removing the screws - four in total - and I left two screws on opposite corners to be removed last. I was able to keep the spring compressed easily with one hand. The rebuild kit contains new diaphragms and the only way you can replace them is to take the thing apart which the manuals say not to do. I guess they want you to take them to the dealer so they can charge you big bucks. I will admit I made a mistake by not noting the location of the cone shaped cup on the threaded bolt. I hope someone else who has taken one of these apart can remember about how far the metal tab on the cone shaped cup was located from the end of the opening on the side of the spring cover. If my memory serves me correctly I am thinking maybe 1/8 of an inch. Thanks for any assistance. - See more at: http://www.corvetteactioncenter.com...corvette-warm-start.html#sthash.sDmAbebE.dpuf

 

[garyc4]

Late, but hope it helps

When I took mine apart, the tab was about a third of the way up, from the bottom of the slot in the FPR housing. Also, I checked the position on a spare CFI setup I have on the shelf and it is similar.

I know this response is 2 years after your question and you have undoubtedly solved your problem by now.

As an aside, I would suggest considering popping out the bottom plug in the (rear) FPR housing so that you can access the screw adjuster before re-assembly. Then you can adjust when engine is running and get it right.

Of course, to do that you need a way to measure fuel pressure, and a way to reach the screw/tab. DCS used to sell the solution for this, and I don't know if anyone has taken up that mantle since they went away. But if youre ambitious you could certainly fabricate these items.