North American Turbocoupe Organization



detonation problem
capri1979 Offline
Junior Member
#1
Hi, new member here. Got a 87 turbocoupe that i had a bad turbo when i got it. New parts put on it: cap, rotor, plugs, wires(motorcraft), turbo. As soon as it warms up it starts pinging. It runs good and no check engine light. I backed the timing down to 7 degrees, i have 40 psi of fuel pressure and 20 in of vacuum. I searched on here quite a bit before finally becoming a member now and posting. Also have fresh 93 octane. I may try some seafoam and get a code scanner. Any things i missed or some advice? Thanks!
rusty
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Pete D Offline
Administrator
#2
You could have an air leak, like one of the intercooler hoses, or the VAM hose. Take them all off and inspect them completely. I fought this same problem for too long. It was a hole in an IC hose.
Try this first before throwing $$ or parts at it.
Pete Dunham


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capri1979 Offline
Junior Member
#3
thanks, actually have seen you post this in some of my searches, i will double check these again.
rusty
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turbospoolin23 Offline
Senior Member
#4
Welcome to the forum. Are yor running a stock ihi turbo or something larger?
87 TC 5 spd... 17X9 Cobra R's, .60/.63 SVO T3 Turbo, Large NPR, Manual Boost Controller, AEM Wideband, BPV, K&N Cone, Walbro 255, Kirban AFPR, 3G Alternator Conversion, Short Throw Shifter, Stinger 3" Exhaust, Magnaflow Catalytic Converter & Muffler.
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Jeff K Offline
Administrator
#5
What shape are the injectors in? If the car sat for a long time, one or more could be partly plugged. Have you read the plugs looking for 1 or more lean cyls?

You dont need a code scanner. You can do it with a jumper wire and watch the CEL flash the codes. There are instructions here and all over the web for doing this.

The only injector / fuel system cleaner worth anything is the stuff with Techron.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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capri1979 Offline
Junior Member
#6
turbospoolin: IHI

jeff k: the plugs all look fine. Its starts fine with no noise, as soon as it hits operating temps it starts makin noise. Pull the spout pill its goes away.

I think i may make a vid of what it does and post it up. the only thing that is not hooked up is the coolant sending unit for the gauge, PO broke it and just installed a cheapo temp gauge.
rusty
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Blue Oval Bird Offline
Member
#7
I'm curious about this as well as I have an 88 with 75k miles on it that does the same thing. Runs perfect until it reaches normal operating temps and then it has pre-ignition like crazy. Has all new plugs, wires, cap and rotor. Running 93 octane plus octane boost. Has plenty of boost even at low RPM's. 100% bone stock except for K&N filter on VAM. Runs like a dream from cold to operating temp. Temp guage stays pretty low while driving at speed but goes from a quarter scale to three quarter scale while stopped. Fan does come on and temps do come back down to half scale while stopped, but temp stays at quarter scale while moving leading me to believe that the thermostat is working properely as long as there is good air flow. The fan comes on way higher on the scale than I'd like (I know it's the unreliable stock guage) but wonder if it's running too hot. I have a new 180 tstat and sending unit for the PCM / fan control and contemplating a piggyback aftermarket adjustable fan control to cut the fan on at a lower temp of around 200 degrees with the trusty ford sender as a backup at 220 degrees. Curious if anyone else has battled the dreaded operating temp ping?
1988 Turbo Coupe: 5-speed, 75k original one owner garage kept miles.

MODS: K&N filter on the VAM, Gillis Boost Valve @ 16 PSI, Walbro 255 lph pump, Kirban AFPR, Full STINGER 3" turbo back exhaust with Magnaflow muffler, Motorsports 140 MPH Speedometer.
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capri1979 Offline
Junior Member
#8
Well not sure if this has anything to do with it but my BCS blew apart when i took it for a ride tonight. I guess i need a gillis.
rusty
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Blue Oval Bird Offline
Member
#9
If it were only that easy. I'm going to order a Gillis as well but hesitant with the pre-ignition condition. I don't want to throw more boost at it if it's not going to be happy about it in the first place. Perhaps you may have stumbled onto the problem and mine just hasn't fully let go yet. Time will tell.
1988 Turbo Coupe: 5-speed, 75k original one owner garage kept miles.

MODS: K&N filter on the VAM, Gillis Boost Valve @ 16 PSI, Walbro 255 lph pump, Kirban AFPR, Full STINGER 3" turbo back exhaust with Magnaflow muffler, Motorsports 140 MPH Speedometer.
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BJL Offline
Moderator
#10
i had a similar issue back in 2001-2002. i had bought a used engine in pieces from a SVO guy. not knowing much about 2.3's i trusted him. after insralling this engine and finally getting the car i would detonate when hot. my father advice was to stop racing around (i was 17).i chased detonation for months, we ended up leaving the spout out.
well i replaced that engine in 2002 when i burned a piston (becuases of detonation),it would smoke when the engine got hot. i put in the new/used engine and it wouldn't detonate unless i had it at 15* base. this engine i got from nato member john marshal. all worked well then. never looked any further.

the beginning of this year i was doing extensive research on 2.3l heads. i was reading about n/a heads with the heart chamber causes engines to detonate with boost. the more i read the more fimiliar is sounded. so out of curuisity i went into my shed, where that engine has been sitting since i took it out. i took of the head and sure enough. it was a n/a head with the heart chamber.

it seemed that the 2.3 turbo heads crack around the exhaust valve seats. and basic auto repair shops were installing n/a heads on cars that popped head gaskets or had other head issues.

this may not be your problems but it was mine. just took 8 years to figure it out.
just my 1/2 a cent
Brian J Larkin
88TC 328,000 miles
T3, FMIC ,3in stinger exhaust, PimpXS ECC,gillis,
255 walbro, afpr, 5spd swap,spec clutch, sn95 5 lug, Cobra 13in front brake. Vacuum assist brake conversion. 
89 Cougar XR7 3.8SC Auto
95 Ranger Splash 3.0 auto
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