I wasn't going to port the heads origionally. I did want to make the ports symmetrical so that when I put the upside down manifold on the rear of the motor, it would match up fairly well. You can see where that Idea went. The ports are now not only symmetrical, they are now huge. Ok, so it's official, I am porting these heads. I got a good start on it: The ports are huge, but I have to open the area around the center fin, and narrow the center fin a little so that the ports transition well. Believe it or not, the ports are now the same area as the 96 - 97 heads are. Oddly, the center fin on 91-95 heads have coolant running through them, so I cannot narrow it much at all. I will have to hog out the manifolds to match. here is some hard numbers: Area of the port (neglecting rounded corners) Stock 91-95: 2.46" Stock 96-97: 2.92" Ported 94 head: 2.95"
This is going to be fun.
[This message has been edited by Fierobsessed (edited 01-11-2007).]
I don't think the ECM really gets much feed more than "load or no load", everything electrical goes through the AC relays and fuses, which would be the same as before. Even the Cycle switch should use the same ECM output. Right?
Please correct me if I'm wrong. I want to know as well.
That's not all there is. Look for the A/C Pressure Sensor in the schematics. It requires you to run 3 wires to a sensor on the high pressure line. You'll probably have to weld in a bung for it. Alternatively you can use an 87-88 Fiero 4-cyl A/C compressor and wire it like it is in the Fiero. It has low- and high-pressure cutoff switches on the compressor itself.
The A/C pressure sensor has three wires for a reason. It is a transducer NOT a switch, it reports to the ECM an analog pressure, and the computer determines if the conditions are correct to turn on the A/C compressor. This system is much simpler and more reliable then the Fiero style A/C control setup. I recommend using it exactly as it was intended for the 3.4 DOHC.
Call me cheap... I am going to use the 87 Fiero compressor and wire it up to the original circuits. I am also going to send the A/C request to the ECM and put two 10K resistors on the pressure transducer. This will kick the fan on and bump the idle. The A/C in the car was previously switched to 134 and worked very well. My harness is done except for A/C and I want to install it this weekend.
I have a observation though: On my C203 the TBI1 and TBI2 wires are not present on the engine side. They were wired on the car side, so I pinned them on the engine side and are using them for my injectors, have not seen this documented elsewhere.
I have a observation though: On my C203 the TBI1 and TBI2 wires are not present on the engine side. They were wired on the car side, so I pinned them on the engine side and are using them for my injectors, have not seen this documented elsewhere.
Please document it then.
I'm going throught the same thing with A/C. I want to use the new compressor rather than the 2.8 compressor. I have a hate relationship with the old one.
I'm going throught the same thing with A/C. I want to use the new compressor rather than the 2.8 compressor. I have a hate relationship with the old one.
Instead of welding a bung in the high pressure line ($$$) you can just fit an O-Ring in a pressure transducer from a donor car and thread it onto the high pressure tap by the spare tire after you remove the shreader (SP) valve. You will have to run some longer wires to the front of the car but it beats having to take chances with getting your aluminum A/C lines welded.
As I posted on 60degreev6.com I am trying to build a virtual LQ1, and need some obscure measurements from the lq1 and so far have some, but if anybody is willing to take some for me, It will help me buuild this motor and get some results posted, and with this program I will attempt to make some optimizations to some specifications. well here's the post i made...
I recently acquired a program that i think is miles ahead of DD2000, and I'm attempting to build a LQ1 in it, but require a few specifications on the motor, that aren't widely published, I know there are a few users here that know these specs, or have enough part motors to get measurements. I am asking for the forum help to gather this information to help unlock the power of this motor. This program so far is godly in the data you can input into it. So, Right know I'm looking for the rod length, and any head data that is known, like runner length and port diameter, intake plenum volume, obscure measurements like these are what this program takes. Any help is much appreciated.
INeed help confirming something. I have a pegged oil pressure gauge when I start my car. It is a 92 motor. I assume that it is because my oil pressure sending unit was for an idiot light and I need to order a new sending unit for a gauge output. I see two different part numbers on the Auto Zone website. If I change this does the pin out of the sending unit change? Thanks
P.S. I have searched and read everything on the DOHC that I can find I might have missed this though. I have very limited band width on the ship so it takes hours just do down load a thread.
INeed help confirming something. I have a pegged oil pressure gauge when I start my car. It is a 92 motor. I assume that it is because my oil pressure sending unit was for an idiot light and I need to order a new sending unit for a gauge output. I see two different part numbers on the Auto Zone website. If I change this does the pin out of the sending unit change? Thanks
P.S. I have searched and read everything on the DOHC that I can find I might have missed this though. I have very limited band width on the ship so it takes hours just do down load a thread.
Yep, the idiot light sensor is just a pressure switch, not a variable pot. It will show the oil pressure as pegged when running and zero when off. I think the Fiero sensor will work.
This is how it sits right now. It runs well, but needs exhaust. I can't imagine trying to get the exhaust in there. I will take it to a exhaust shop next saturday. (still have coolant plumbing to attach) Thanks to all for the help. James
I'm so sorry but I don't yet. I can get some when I get the car running and out of the shop though. I don't think there's enough light to get any good pictures.
since this is the "dohc topic" i have a question for all of you,if you don't mine if so i will delete my post,
I'm swaping my fiero and using a dohc 3.4 engine from a montecarlo 1997 got the engine,wiring,and pcm
and got everything running :)
I have instald pcm obd2 and don't use the VATS can this give a problem do i need to install it or leave it of line and delete the code comands from the pcm.
when i start the engine the engine runs and everything is ok but if i give some gas the engine whant to stop,if i stop to give gas the engine will go on what can this be?
And it is not a bad sensor on the block or fuel/air lines Cam, Crank, Mass air flow, or really any sensor! i used a multimeter to check every wire and sensor everything is okee,
the only thing i did not do: Read the pcm,on to my laptop,still waiting on a cable from aldlcable hope to get it tomorow and the eprom is still originall and i hope to delete some camands from the pcm like automatic gearbox,egr,and all i whant to use DHP's powrtuner
Probing possibilities of having more technical troubles with the ECM after I get past the theft system. I have been told that with a manual transmission, the ECM may try to put the motor on "limp home/safe" mode because it thinks the tranny is possibly damaged.
What other problems besides a rev limiter will I be running into without a reprogrammed ECM from Darth?
It's a 95 Monte Carlo ECM and motor.
[This message has been edited by Emc209i (edited 12-05-2008).]
Can it be that if there is a wire (the 12V)that is not the right diameter to big/small the engine will run but if you give some gas the engine whant to stop ?
Possibly. Do you have a reprogrammed ECM yet? I'm running into technical difficulties myself and I think the only way I can around them is a reprogrammed computer.
I really don't know where everyone else is, there are people far more knowledgeable on the topic than I am, and I wish they'd speak up to help.
honestly it sound like the cost of a reprogrammed computer would outway the headache of a whole lot of trouble shooting. It's only 45$ and From what I hear, the 94-95 computer = haxed fo sho.
Instald the cable and Digimoto software and it read the pcm yes yes :)
the code's it give me was:
P0102 Mass or Volume Air Flow Circuit Low Input P1860 TCC PWM Solenoid Circuit Electrical/Transmission Transfer Case Contact Plate"D"Short Circuit To Battery
ghe ghe yes:)
and now wat .wat do i need to do so that the code's are going away ......... some help please
P0102 Mass or Volume Air Flow Circuit Low Input P1860 TCC PWM Solenoid Circuit Electrical/Transmission Transfer Case Contact Plate"D"Short Circuit To Battery
Daniel Dogge
[This message has been edited by Emc209i (edited 12-05-2008).]
Has anyone mounted a centrifugal type supercharger on a DOHC yet? If so where did you mount it, power steering? I have been thinking about attempting it. I was going to turbo but I think it will be too expensive and I'm hoping the Vortech style sytem will be more reliable. Thaughts? Also if anyone has completed such a swap is the some dyno #'s on it?
Anyone happen to know what the calculated loss (average) of a vortech style supercharger. I'm not wanting to run that high of boost in hopes of maintaining some reliability. I wondering if the loss would force you into running higher boost, and therefore affecting reliability.
question for ya guys. I have a good idea what im going to do to remove power steering and I know the idler setup im going to use . My question to you guys is what kind of idler system did you use to delete the a/c? I want that outta there too what did you guys do for that and do you guys have any pictures to show how and what you did that would be great thanks
Icut the fuel lines on my 87 Duke just before the threaded fittings on the rubber lines. Then I ran steel brake lines against the firewall and up to the location of the Evap canister, from there I ran two short Fuel injection rubber lines with Fuel line clamps to the steel lines under the throttle body. My engine is a 93 with an Isuzu. I do not have any pictures but I followed the route that it seems everyone else does.
As far as power steering delete goes, I have one for sale. PM me if your interested.
As far as the 94-95 ECM goes when I first got my car running it was with the stock 95 ECM on a manual transmission. I did nothing to bypass the automatic transmission wires (such as hook up solenoids etc) and my car ran trouble free. The biggest thing that I had to overcome was the VATS bypass. When I started the car the first few times it would start and run great but shut off two seconds later. To take care of that, I ordered the VATS bypass modual off ebay. http://cgi.ebay.com/ebaymot...dZ1QQsspagenameZWDVW
That was before sinster performance could do anything for the 94-95 ECM. Now I wouldn't even mess around with the stock ECU if I were you. Just pay his low chip burning cost and get it done. There is life above 6500 RPM's on these engines after all.
bad connector,man i just can wwwwwwwhhhhhaaaaa
sorry.
