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Modifications Changes from the factory stock setup - performance and appearance. What to buy next? What works & what doesn't?

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Old 10-17-2010, 09:05 PM   #16
Chris-90LX
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That 14.0 time at 99mph is very good.

To drop to 81mph tells us you have a serious power drop. In plain language, the car should be going quicker and certainly faster after your recent upgrades.

Sounds like the problem could be something basic.

How does the gas mileage look when using the car as a daily driver?

Double check your ignitionís firing order.

Check for any possible vacuum leaks.

Is there any chance the clutch might be slipping?

Check what fuel pressure looks like.

Are the spark plugs showing a serious lean condition?

When you set up the MSD ignition, did you reconnect the vacuum advance?

Keep us posted on this.

Like what Mike just said, if the old and new 60ft times are consistent, something big is happening all the way down the track.
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Old 10-18-2010, 03:13 PM   #17
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Wow, thanks Skunk for that little bit of light reading material

and chris for your thoughts as well........

We're getting really good gas mileage now so its another indicator of lean mix

We checked for vacuum leaks spraying carb cleaner around the pipes and joints but didn't detect anything but we're not ruling that out just yet.

Instead of a three way split on the vacuum we ran a dedicated vacuum pipe to the fuel pressure sensor and got slightly higher fuel pressure than before, but that was before we got to the strip !!

My son also reminded me that we got the 14.013 with the bigger MAF fitted but still had the standard throttle body and 5.0 intake manifolds back then so I guess the 94-95 MAF is working OK or was.

Well I know its damn hard trying to analyse and 'fix' things from miles away and we appreciate the suggestions...... so we'll let you know if what we find, if anything is obvious that is

For the moment we are going to return everything back to how it was when we did the 14.013 as we've noticed the front left bolt lug on the Trickflow upper inlet manifold has fractured off (its brand new!) where it bolts to the lower manifold - its a hairline crack, so we gotta get that TIG repaired.... that might be indicative of some other problem when we remove it...
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Oxford White 1989 GT 5.0 mild cam, roller rockers, headman headers, side exit pipes, de-catted, de-smogged, racing clutch, 3.73 gearing, A/C eliminator, Steeda Tri-ax, Cobra grille insert, 17 x 8 Cobra R rims,45 profile tyres, Wilwood Superlite 6 big brake kit, Roll cage, rear seat delete, MM K Member, MM front lower arms, MM Coilover Koni shocks, MM caster camber plates, Hurst roll control, MSD Pro Billet distributor, MSD Streetfire Coil, FRPP ali rad
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Old 10-18-2010, 05:05 PM   #18
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Quote:
Originally Posted by Raven68
Wow, thanks Skunk for that little bit of light reading material

and chris for your thoughts as well........

We're getting really good gas mileage now so its another indicator of lean mix

We checked for vacuum leaks spraying carb cleaner around the pipes and joints but didn't detect anything but we're not ruling that out just yet.

Instead of a three way split on the vacuum we ran a dedicated vacuum pipe to the fuel pressure sensor and got slightly higher fuel pressure than before, but that was before we got to the strip !!

My son also reminded me that we got the 14.013 with the bigger MAF fitted but still had the standard throttle body and 5.0 intake manifolds back then so I guess the 94-95 MAF is working OK or was.

Well I know its damn hard trying to analyse and 'fix' things from miles away and we appreciate the suggestions...... so we'll let you know if what we find, if anything is obvious that is

For the moment we are going to return everything back to how it was when we did the 14.013 as we've noticed the front left bolt lug on the Trickflow upper inlet manifold has fractured off (its brand new!) where it bolts to the lower manifold - its a hairline crack, so we gotta get that TIG repaired.... that might be indicative of some other problem when we remove it...
glad the info helped It's pretty good. another good tool to have is a vac gauge. if and when you get the new heads, etc you would probally do well with a tune. alot of people do not agree but in some cases it does well and can clean up the air/fuel ,etc. you will need to reprogram the ecu anyways when going to 24 injectors but they can do much more, also another way to grab as much has 10hp is to degree the stock cam, it's is sloppy from the factory but it works for the masses in thier eyes. verifying the timing events even with the stocker can free up some hp. good luck and keep us posted.
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Old 10-19-2010, 02:54 AM   #19
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Whats the compression like?
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Old 10-19-2010, 06:30 AM   #20
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Quote:
Originally Posted by fb93
Whats the compression like?
Yep, good point we'll check that out as well.

Thanks skunk - we tried a rolling road session before but they couldn't keep the car on the rollers due to one rear wheel being out of true? Once we've sorted that we'll be back for a tune up session.

Probably obvious to some but I didn't realise you could reprogramme the ECU

Yep we're getting a vacuum gauge for the toolkit now !

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Old 10-26-2010, 10:48 PM   #21
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Sounds like you've done a good job trouble shooting so far. Here's a few other things to look at...

Have you verified the throttle plate is opening all the way? Sounds silly but its possible.

While you're there, make sure the Throttle Position Sensor is showing close to 5v when the throttle is opened up all the way. If the EEC was seeing too little voltage and the throttle was all the way open, it would be way lean. Sometimes a brand new throttle body may need the TPS set properly. It's a good thing to check, if for any reason, to get used to trouble shooting EFI systems...
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Old 10-27-2010, 02:25 PM   #22
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Quote:
we tried a rolling road session before but they couldn't keep the car on the rollers due to one rear wheel being out of true?
Do you feel a shake or wobble from the rear end while driving? If so, check for a tweaked axle shaft. I had one a few years ago after an accident and was bent slightly just behind the flange at the wheel. The wheel was cracked as well next to one of the lugs.

When dealing with fuel injection, its a good idea to have a few manuals handy. I highly recommend these two:

'How To Understand, Service and Modify Ford Fuel Injection & Electronic Engine Control' by Charles O. Probst. Covers 1988-1993 EEC-IV as well as MECS (Mazda). Includes trouble codes for both systems. This manual is awesome!

'How To Tune & Modify Ford Fuel Injection' by Ben Watson. Covers EEC-III and EEC-IV. Includes trouble codes for FWD and RWD. Some codes are handled differently depending on the engine. This manual covers those differences.

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Old 05-04-2011, 04:41 PM   #23
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Sorry guys not been back on here a while, but we've had a lot going on over the winter here in the UK..

My son has been removing lots of redundant wiring from the engine bay and tidied it up real nice. Rear axle was removed, painted and refitted with Maximum Motorsport arms and we found a broken coil spring in the process.
Finally we removed all the Trickflow intake and put it back to stock and took it back to the strip this past weekend and it still ran out of puff, so even in stock setup we can't get back to where we were... We had the stock injectors checked and cleaned and they were OK. Car still feels as though its running out of steam. There's no 'pull' above 3500rpm so we'll check out the fuel delivery side.

Thanks qikgts - throttle position is not a silly suggestion at all. We checked the voltage when closed but not fully open so we'll do that.

Thanks fb93 for the manuals - will see if we can order them. Still haven't checked out the possible axle wobble but will be doing that this weekend.

Thanks again guys... will hopefully keep you in the picture now we have some sunshine to go racing with !!
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Oxford White 1989 GT 5.0 mild cam, roller rockers, headman headers, side exit pipes, de-catted, de-smogged, racing clutch, 3.73 gearing, A/C eliminator, Steeda Tri-ax, Cobra grille insert, 17 x 8 Cobra R rims,45 profile tyres, Wilwood Superlite 6 big brake kit, Roll cage, rear seat delete, MM K Member, MM front lower arms, MM Coilover Koni shocks, MM caster camber plates, Hurst roll control, MSD Pro Billet distributor, MSD Streetfire Coil, FRPP ali rad
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Old 06-09-2014, 07:50 AM   #24
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Raven,
What did you and your son end up finding on your performance problem?
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