New rebuild, strange loss of power

Covers all sn94/95 mustang v8 ecu's.
Pappacosworth
Posts: 17
Joined: 2021 Feb 17, 14:14
Location: Finland Ilmajoki
Vehicle Information: SIGNATURE
Ford Mustang Cobra -94. Ported M112 ratio 2.375:1, 4.6 Dohc, ported c-heads, TR3650, 3.55 IRS, ZYA2
Coretuning/Moates/HPTuners/Innovate/Tunernerd Knock Monitor/

New rebuild, strange loss of power

Unread post by Pappacosworth »

Car is 1988 Fox, ECM is 1994 cobra with CBAZA strategy. Fresh rebuild with new parts, block is original: 030" over, forged balanced bottom end, Trickflow 170 heads with rollers, Trickflow stage 2 cam timed according to cam card. 61 cc head volume, -2 cc pistons, 0.039" gaskets. Piston little under deck 0.02"
Comp ratio 9.8. Edelbrock performer copy intake, 70mm tb, bbk shorties. Car is slow... afr error under 5%, timing little over standard. Any tips before I start disassembling it again?
ajocl14 2021_Oct_31_16-46-40.zip
wot accelerations near end
(922.58 KiB) Downloaded 191 times
red5.0fogger
Posts: 148
Joined: 2021 Mar 22, 15:58
Location: Newington CT
Vehicle Information: 1986 Mustang GT, Stock block, TFS 170 Heads , N41 cam, ported cobra intake, nitrous, T5 , 3.73s

Re: New rebuild, strange loss of power

Unread post by red5.0fogger »

Did you verify base timing with a timing light?
Pappacosworth
Posts: 17
Joined: 2021 Feb 17, 14:14
Location: Finland Ilmajoki
Vehicle Information: SIGNATURE
Ford Mustang Cobra -94. Ported M112 ratio 2.375:1, 4.6 Dohc, ported c-heads, TR3650, 3.55 IRS, ZYA2
Coretuning/Moates/HPTuners/Innovate/Tunernerd Knock Monitor/

Re: New rebuild, strange loss of power

Unread post by Pappacosworth »

Yes, timing is correct. Cam is timed with degree wheel, and damper markings checked.
red5.0fogger
Posts: 148
Joined: 2021 Mar 22, 15:58
Location: Newington CT
Vehicle Information: 1986 Mustang GT, Stock block, TFS 170 Heads , N41 cam, ported cobra intake, nitrous, T5 , 3.73s

Re: New rebuild, strange loss of power

Unread post by red5.0fogger »

maybe triple check the firing order. 5.0 is different than 302.
Pappacosworth
Posts: 17
Joined: 2021 Feb 17, 14:14
Location: Finland Ilmajoki
Vehicle Information: SIGNATURE
Ford Mustang Cobra -94. Ported M112 ratio 2.375:1, 4.6 Dohc, ported c-heads, TR3650, 3.55 IRS, ZYA2
Coretuning/Moates/HPTuners/Innovate/Tunernerd Knock Monitor/

Re: New rebuild, strange loss of power

Unread post by Pappacosworth »

Good point. Compression test 157-160 psi so DCR should be correct.
decipha
Posts: 4899
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: New rebuild, strange loss of power

Unread post by decipha »

log is csv. Best to log with tunerpro so you can see exactly what going on
Pappacosworth
Posts: 17
Joined: 2021 Feb 17, 14:14
Location: Finland Ilmajoki
Vehicle Information: SIGNATURE
Ford Mustang Cobra -94. Ported M112 ratio 2.375:1, 4.6 Dohc, ported c-heads, TR3650, 3.55 IRS, ZYA2
Coretuning/Moates/HPTuners/Innovate/Tunernerd Knock Monitor/

Re: New rebuild, strange loss of power

Unread post by Pappacosworth »

13726548 351w / H.O. order used
red5.0fogger
Posts: 148
Joined: 2021 Mar 22, 15:58
Location: Newington CT
Vehicle Information: 1986 Mustang GT, Stock block, TFS 170 Heads , N41 cam, ported cobra intake, nitrous, T5 , 3.73s

Re: New rebuild, strange loss of power

Unread post by red5.0fogger »

Is it stick or auto trans?
Blocmi
Posts: 26
Joined: 2021 Feb 16, 11:13
Location: Connecticut
Vehicle Information: 1995 Mustang GT, CBAZA, 11:1 306, Ported Windsor Sr. aluminum heads 2.02/1.60, Trick Flow Track Heat, 24lb injectors, Comp cams 294/306 (2,800-7,000), Shorty headers, X-Pipe, Reverse Manual VB C4, 4100 stall converter, 4:10, MT ET Drag 26-10-15

Re: New rebuild, strange loss of power

Unread post by Blocmi »

Pappacosworth wrote: 2021 Nov 03, 14:41 13726548 351w / H.O. order used
Was the previous cam / tune HO or non-HO firing order?

I swapped firing order, swapped plug wires around, but forgot to change the injector firing order in the tune and it certainly made a difference once I corrected the tune.
Pappacosworth
Posts: 17
Joined: 2021 Feb 17, 14:14
Location: Finland Ilmajoki
Vehicle Information: SIGNATURE
Ford Mustang Cobra -94. Ported M112 ratio 2.375:1, 4.6 Dohc, ported c-heads, TR3650, 3.55 IRS, ZYA2
Coretuning/Moates/HPTuners/Innovate/Tunernerd Knock Monitor/

Re: New rebuild, strange loss of power

Unread post by Pappacosworth »

Manual, 3.73 rear. Ignition order has been same before. Car is 1988 Mustang GT, was with map ecm. Wiring repinned to 1994 schematic, no ccrm, egr, thermactor. 4 pin maf, iat sensor at intake. No fault codes. New injectors (1995 Tbird SC), values from Tbird calibration.
Stock airbox, new filter.

Code: Select all

Cylinder Head Volume (cc)	61
Cylinder Head Vol (cubic in.)	3.721
Piston Head Volume (cc)		-2
Piston Head Vol (cubic in.)	-0.122
Gasket Thickness (in.)		0.039
Swept Volume (cubic in.)	38.267
Gasket Bore (in.)		4.1
T.D.C. Volume (cubic in.)	4.318
Cylinder Bore Diameter (in.)	4.03
Gasket Volume (cubic in.)	0.515
Deck Clearance (in.)		0.016
Note: Neg. number above deck, Pos. number below deck	
Deck Volume (cubic in.)		0.204
Stroke (in.)			3
STATIC COMPRESSION RATIO	9.862
OPTIONAL DATA
Rod Length (in.)		5.09
Adjusted Stroke (in.)		2.528
Intake Closing Point (degrees) ABDC @ 0.050 lift plus 15 degrees	
				54
DYNAMIC EFFECTIVE COMPRESSION RATIO	8.468
Post Reply