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Serious detonation!

Well I went to look at a XR4 for my son. Part of the fun of having kids is getting them cars you would like to own. Anyway this was a nice black on black car with sunroof, leather etc. It has been sitting on the car lot for a while. Price on the window? $1600.

It started right up. No smoke. Exhaust leak, air doesn't work, power window doesn't work, heated seats don't work. power mirrors don't work etc. But good body, tires etc.

Took it around the block. Man the tach moved too quick! The boost went way past 20 lbs in an instant. There was no way you could stop to shift!

But instead of normal detonation (you know the marble sound rolling around in the engine) This thing made sledge hammer sounds! Four big poundings before the computer cut out. Restarted it moved out through the gears and it ran strong. Then the sledge hammers again!

Just no way to jump on the throttle in first.

Oh well I guess I had to pass on it. But it was a lot stronger than my 84 GT.

Anyway that was detonation wasn't it? I have never heard anything like it in my life!


Could it have been a collapsed lash adjuster (or more) rattling the s**t out of the cam followers...?

88TC 5spd Vermillion Red,Crower 5.5" Sportsman Rods & Short Wiseco Pistons bored .030" Over, Ported Head with Polished Combustion Chambers, Gutted & Polished Upper, Ported & Polished Lower w/Knife Edge, Polished T/B, Polished Intercooler, Ported E6 with 2400deg coating, SVO T3 .63AR Turbo, Bosch BPV, Braided Oil Feed Line (PnRVegas), 3" DP w/No Cat, 2 1/2" single DynoMax Cat-back & Dynomax Super Turbo Muffler, RR Cam, K&N in Fenderwell, Gillis Boost Valve, Centerforce I Clutch, Removed A/C, Polished Wheels, Polished Valve Cover, Polished W/P, Polished Crank and W/P Pulleys, Walbro 255LPH HP Fuel Pump, Kirban Adj FPR, and the DAMN Heater Core is new too !
88TC 5spd,5.5" Rods,+.030" OB Pistons,Ported Stk Head,Gutted Upper,T3 .63AR,BPV,3" DP,2.5" DynoMax Catback,RR Cam,K&N,Gillis,CF-I,255LPH Pump,AFPR

or it could be like my head, abnormally strong (300lb. open) valve springs and big valves

88TC - 5speed, all options but leather and sunroof
Esslinger Prepped head, AiResearch T-3, 3.73 gears, Schneider custom grind cam, chromed rims, dynomax on the duals, and last but not least... new interior
[Image: js_88tc1small.jpg]Have you hugged your SHO, TC, or SVO today?
Looking for another TF.

Marbles compared to sledge hammers, wow, that would be quite interesting. I suppose that it could be the valvetrain but sounds a little too drastic for that.

I've never heard valvetrain sound like a sledgehammer. If the boost went past 20psi and no IC you can bet it was knock'n. Maybe the knock sensor was unplugged/not working. Maybe you shouldn't have passed on it, might of just needed the boost turned down/fixed and a tune up.

74 pinto project: 8 point cage, 87TC engine,T5 tranny,T3,ported head,fresh valve job,felpro 1035,K&N on VAM,18 psi and 150 shot wet NX kit,stock DP with no muffler,mini spooled 8 in. with 3.55's, BFG drag radials,RAM 6 puck, SVO front mount with custom tanks,race seats and 5 points,entire car stripped for weight (including hood and bumper). Hoping for low 11's!!!

Yeah! Go back and get that puppy! It's probably got a bellyfull of regular gas, too.
Add that onto high boost and no IC and you get guaranteed knock. And not the light kind either.

yeah, but how long has it been like that and how bad is it inside the engine!!!!
Newbie with dumb newbie questions...
some wiring diagrams and by some , I mean none at all.
1984 GT350 T-top New pics
1984 Turbo GT T-top 419rwhp

Sounds like the wastegate actuator isnt working or not hooked up.
20psi boost + no intercooler = detonation big time!
Big valves & ported head, welded & gutted intake, ported E6, 2.5" turbo outlet, manual brakes & steering, aluminum flywheel & driveshaft, 8.8 w/3.73.

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