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Computer removal/elemination by trotterlg
Started on: 08-09-2013 06:33 PM
Replies: 21 (513 views)
Last post by: carbon on 01-31-2014 10:42 AM
trotterlg
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Report this Post08-09-2013 06:33 PM Click Here to See the Profile for trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
I am dropping the engine to replace it with a completely non-computer engine. I would like to have the Oil Pressure, Spedo, Tach, Temp Gauge, Alternator (with indicator) and the fuel pump work when I am done. I am removing the entire harness with the cradle. Do any of these things require the computer to be present for them to work? If so is there a work around for it? 4 speed Muncy if it makes any difference. Larry

[This message has been edited by trotterlg (edited 08-09-2013).]

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Report this Post08-09-2013 06:46 PM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
None of those circuits require the ECM so you should be fine. You will need to wire the fuel pump so it turns on with the key in the "start" and "run" positions though since the ECM normally controls the fuel pump relay. Obviously it's not essential though since the back up circuit for the fuel pump is through the oil pressure switch.
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trotterlg
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Report this Post08-09-2013 07:17 PM Click Here to See the Profile for trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
Then the fuel pump should be OK because this has a carb on it and should have plenty of gas in the bowl to start and get oil pressure up. Do all these things go to one connector some place? Larry
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phonedawgz
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Report this Post08-09-2013 07:17 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'd run your fuel pump on the oil pressure switch only. You don't want the chance it would remain running in a crash.
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trotterlg
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Report this Post08-09-2013 07:25 PM Click Here to See the Profile for trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
I am thinking that also, are there two oil pressure switches? Like one on off and one for the pressure gauge? I only have one in the new engine now for the gauge. Larry
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Report this Post08-09-2013 07:34 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
The two outside pins of the sender are the pressure switch. That closes when you have over 5 psi of pressure. The center pin is the gauge. The return on that circuit is the engine ground, so it only has one wire.

So maintain the center wire to the gauge (C203 pin E). You can cut off the relay and just maintain the wiring to the oil pressure switch (C203 D - Orange Black (Fuel Pump Fuse unswitched +12) and C203 L - Tan/White (Runs to the Fuel Pump))
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trotterlg
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Report this Post08-09-2013 08:19 PM Click Here to See the Profile for trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
I understand, perfect! What kind of signal does the tach want to see?
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Report this Post08-09-2013 08:49 PM Click Here to See the Profile for zkhenningsSend a Private Message to zkhenningsEdit/Delete MessageReply w/QuoteDirect Link to This Post
You could also run the fuel pump wiring through a kill switch that you find in newer cars that kills the fuel pump when your car is in an accident if you don't want to depend on the oil pressure switch.

I do not know what you would do for the tach since you are using a different distributor I assume... But I am pretty positive it is linked with the pickup coil/ reluctor so the gauge itself receives reference pulses every time the plugs fire and converts that to RPMs, since you are still a 6 cylinder I think you could get it to work with the stock gauge without modification to the gauge.

I want to see what this engine can do in your car!
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trotterlg
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Report this Post08-09-2013 10:46 PM Click Here to See the Profile for trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
We will find out soon enough, I am sort of past the point of no return on the swap. I have new rear struts and 1 1/2 inch lowering springs to go in. All the cradle bolts are loose and the nuts off the front ones. Drained the transmission oil so I won't make a mess when I pull the axels. I may pull it out tomorrow or Sunday. Larry
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trotterlg
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Report this Post08-10-2013 12:52 AM Click Here to See the Profile for trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
I also have a reduced height work space. I do have a very strong wood beam to lift to, I have used it to pull lots of engines. I didn't have enough height to lift using the latch at the rear, the comealong did not have any place to go and I would run out of travel. I put a 2 by 6 under the trunk area, with end pieces to rest on the outer frame. Put a half inch bolt through it and a lifting eye in the trunk, this gives the comealong or chain fall some place to go. I lifted the rear of the car with engine in it, so it will be plenty strong with no engine or transmission. Put the front on modified dollies from harbor freight, I needed the added height so the nose would not hit the ground when I raised the rear. Some Pictures:





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IFLYR22
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Report this Post08-10-2013 01:18 AM Click Here to See the Profile for IFLYR22Send a Private Message to IFLYR22Edit/Delete MessageReply w/QuoteDirect Link to This Post
The Tach works on a PPR (Pulse Per Revolution) of cylinder count/2.
Your 4 cylinder's Tach have a PPR requirement of 2, your 6 cylinder's require a PPR of 3.
This fed from the coil to your Tach via the white wire (i think pin 3 on the C500).

Your SES (check engine) light is only thing that I can think of (in the dash) that is fed from the ECM.

Holley makes an oil sending unit that will let the key turn on the pump to prime the system, but cuts the power to the pump if the oil pressure goes. PN: 12-810
I have installed it on two classic cars.

-Dave

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Report this Post08-10-2013 01:57 AM Click Here to See the Profile for trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
Such great knowledge on this board. Things are looking better and better for me. It will be a fun exchange. The engine was built specifically to be a high truning engine, I think this type of car really needs this type of power plant. It has LS6 springs and a custom ground flat tappet cam that reduces the lifter weight about 30% from the roller lifters, 12 to 1 CR and a Quadrajet carb that can flow enough for a MOPAR 440. We will see what it will work like in a Fiero. It has ZERO electronics, it even has points in the ignition system. Larry
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fieroguru
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Report this Post08-10-2013 07:16 AM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by trotterlg:

a custom ground flat tappet cam that reduces the lifter weight about 30% from the roller lifters,


While the lifters might be lighter, the flat tappet lifters by design limit the ramp rate of the camshaft (due to the relatively flat shape of the lifter bottom - if the ramp rate is too high, the edge of the lifter will gouge the camshaft surface) which greatly reduces the area under the curve. The flat tappet camshaft while having the same overall lift and duration, it will spend much less time at maximum lift vs. the roller camshaft, which will limit power potential vs. the roller.

You haven't stated the peak RPM of this engine, but it isn't difficult to have a hydraulic roller setup good for 7K rpm and you can always go solid roller to go even higher.

Points are also a significant step backwards... you can stick with an HEI distributor even without ecm control.

[This message has been edited by fieroguru (edited 08-10-2013).]

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Report this Post08-12-2013 02:13 AM Click Here to See the Profile for dander10Send a Private Message to dander10Edit/Delete MessageReply w/QuoteDirect Link to This Post
Don't know if you already have solved this, but if you have the standard V6 electric fuel pump it was used with the pressure regulator in the injection fuel rail set for about 45 -55 psi fuel pressure for the injectors. Generally carbs need only about 4-7 psi, and cannot handle much more than that. You may need a lower pressure fuel pump, or regulate it WAY down.
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trotterlg
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Report this Post08-12-2013 12:13 PM Click Here to See the Profile for trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
Yes, I have that solved I think, have this to put in:

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fieroguru
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Report this Post08-12-2013 05:22 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
From the picture, I assume there will be only 2 hoses hooked up to the regulator. One from the pump, the other to the carb.

If that is the case, then its being setup as a dead head regulator and that won't work to drop from 50+ psi to 3-5 psi. To do that, you need a bypass style regulator with 3 hose connections (feed to carb, supply from tank, return to tank).
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phonedawgz
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Report this Post08-12-2013 05:26 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
Is that a bypass fuel pressure regulator? Most standard fuel pressure regulators can't handle the 50+ psi the stock fuel pump will put out without a return (bypass) path.

Check the specs on the fpr for input pressure.
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Report this Post08-12-2013 07:25 PM Click Here to See the Profile for FierokingClick Here to visit Fieroking's HomePageSend a Private Message to FierokingEdit/Delete MessageReply w/QuoteDirect Link to This Post
I think you are going need to replace the fuel pump with a low pressure pump and use the regulator to set the pressure to the carb. Running a 40 psi pump is way over kill.

Joe Sokol

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85 SE Daily driver with a 3.4 DOHC OBD II
88 Formula/GT 4.9 Allante Intake (My Baby)
www.fieroking.com

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trotterlg
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Report this Post08-12-2013 09:57 PM Click Here to See the Profile for trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
Think I will just put a T in the line and a fixed sized hole to bypass fuel back to the tank to get it down to about 15 to 20 pounds and just let it run. I do have an inline carb pump I used to run the engien while it was out of the car, so if you can suck fuel throught the in tank pump I may just use that if plan A fails. Larry
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Report this Post08-12-2013 10:36 PM Click Here to See the Profile for benoitmalenfantSend a Private Message to benoitmalenfantEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well, this is different, flat tappet cam, points ignition in a Fiero.

Although I have to agree with Fieroguru on the advantage of roller cams/lifters, I'm sure the idea here isn't pure performance, but rather something that completely gets rid of electronics and I have to admit, I'll be watching!

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Ben
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trotterlg
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Report this Post08-12-2013 10:56 PM Click Here to See the Profile for trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
We will hope it is not too long now, I got the engine out today, will swap over the parts, have new struts and 1 1/2 in lowering springs to put on, then back in the car and see how things work. I can't disagree that a roller cam has advantages for sure, but a lot of good engines make alot of power with flat tappet cams and it really does simplify and cut the costs of the build, The object is to have an engine that just pulls until you want to shift it, this one should be good for atleast 7,000 and probably limited by lifter pump up, it does have performance lifters in it, but a hydrolic cam has it's limits, and I really didn't want to deal with solids. We will see, here is the mess as it sits now. Larry

[This message has been edited by trotterlg (edited 08-12-2013).]

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Report this Post01-31-2014 10:42 AM Click Here to See the Profile for carbonSend a Private Message to carbonEdit/Delete MessageReply w/QuoteDirect Link to This Post
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