#7 spark plug access with Mustang Hydroboost

Hey All,

Seems like ages since I've been active on this forum, but I've been enjoying my street-duty LS1 swap and it's been running relatively trouble free for years now.

Last year I had some issues with my #7 cylinder not firing, eventually traced back to a bad spark plug (even though the plug looked fine visually). Along the way I tried replacing that plug wire and had a hell of a time even getting the plug boot seated, with the limited room underneath my hydroboost setup.

I have to imagine this is a common issue with how many hydroboost setups are in use on these cars, and was wondering if anyone has any tips or tricks for improving access in that area? My engine just developed another misfire which I'm suspecting is coming from that same #7 plug area.. and I've been dreading going in to investigate. I'm almost to the point of switching the hydroboost out for an electric booster at this point, just to make the car easier to work on. Are there any decent electric setups out there these days?

Access to the #7 spark plug is greatly affected by the type of headers you have on the car. I have a hydroboost setup on my car and I originally had the modified Hooker headers on it. Those headers were compact but they made access top the rear two spark plugs on the drivers side impossible to get to. I purchased a set of Renegade Hybrids shorty style headers and now I can get to the plugs and wires relatively easily. The long tube headers give decent access to the plugs and wires too. You didn't say what type of headers you have on your car but if you have the modified Hookers, I feel your pain. Gil

I have the long tube coated headers from TPC.. it just seems like the length of the hydro boost + master cylinder assembly is too long. Kind of surprised no one has come up with a better solution yet.

948inVA wrote:I have the long tube coated headers from TPC.. it just seems like the length of the hydro boost + master cylinder assembly is too long.  Kind of surprised no one has come up with a better solution yet.

948inVA,

I have the same TPC long tube headers (2014 vintage) and just checked my setup. It seems I have easy access from the front under the Ford HB.  Your setup may have other hoses and the air filter that could get in the way.

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Depends on what year you bought your TPC headers. Mine from 2018, there is zero spark plug access. I have to remove them to change the plugs.

MotoRider42HC wrote:Depends on what year you bought your TPC headers.  Mine from 2018, there is zero spark plug access.  I have to remove them to change the plugs.

I've replaced plugs on both old and new versions of TPC headers. Never had to remove them. Was very easy on both.