96+ intake swap

[dohcfiend]

i recently got a 96 intake and am goign to swap it into a 94 car. i have almost everything covered except 1 maybe 3 things. 1st on the neck between the plenum and the tb, there is a 3 wire plug. what is it for?

next are there any differences in the fuel pressure reg? or do i just hook it to the same line that went to the previous one?

is it ok to bypass the coolant flow to the tb?

[jmgtp]

1.) 3 wire plug was for the map sensor that the 96 used in the TB arm.
2.) You need to use the Fuel Rail and Pressure Regulator from the 96 engine
3.) I bypassed the coolant going through the TB with no problems

Keep in mind, you need pretty much EVERYTHING lower intake on up from the 96 engine (you could reuse your 94 injectors, they just HAVE to be in the 96 rail)- and you will have to make some modification to existing hardware as well. Getting the coolant piping from the 96 engine will make your life easier.

Leave some feedback on how it runs afterward. I'd like to know how the auto trans cars take to it. I noticed a bit of a drop in off idle power through about 2500 rpm but I also retarted the exhaust cams at the same time. Now pulls from 3k straight to the rev limiter. Good Luck!!

[dohcfiend]

i am doing the same thing. i have also heard the 96+ pressure regs are adjustable. is that true and how do i adjust it if it is adjustable?

i am attempting to use all the 94 stuff. like those 2 vacuum hoses in the rearof the pre 96. i unscrewed that assembly from the pre 96 intake.in the 96 it looked to be a freeze plug there, and the hole is the exact same size so i put i put a spare lifter in the plug and with 2 strikes from the hammer it came out and i screwed in the pre 96 assembly.

there are 2 vacuum connections present in the throttlebody of the 96 that will accomodate the 2 connections needed for the 94.

as far as coolant goes there are 3 connections present in the lim of the 96 1 goes to the rad and has the stat.(that goes to the upper rad hose just as the 94). 2 more on the side of the lim. the one on the left has a bolt hole right beside it. that one i will block off by going to the machine shop, getting a scrap piece of metal cut, running a bead of liquid gasket and bolting it down.if that doesn't work i will consider high strength epoxy or something.

the one to the right i will connect it to a rubber hose to it and run it to the heater connection on the firewall.

[jmgtp]

i am doing the same thing. i have also heard the 96+ pressure regs are adjustable. is that true and how do i adjust it if it is adjustable?

i am attempting to use all the 94 stuff. like those 2 vacuum hoses in the rearof the pre 96. i unscrewed that assembly from the pre 96 intake.in the 96 it looked to be a freeze plug there, and the hole is the exact same size so i put i put a spare lifter in the plug and with 2 strikes from the hammer it came out and i screwed in the pre 96 assembly.

there are 2 vacuum connections present in the throttlebody of the 96 that will accomodate the 2 connections needed for the 94.

as far as coolant goes there are 3 connections present in the lim of the 96 1 goes to the rad and has the stat.(that goes to the upper rad hose just as the 94). 2 more on the side of the lim. the one on the left has a bolt hole right beside it. that one i will block off by going to the machine shop, getting a scrap piece of metal cut, running a bead of liquid gasket and bolting it down.if that doesn't work i will consider high strength epoxy or something.

the one to the right i will connect it to a rubber hose to it and run it to the heater connection on the firewall.

I've heard that the 96 FPR is adjustable too but I havent messed with mine because I don't have any need to change the fuel pressure from stock. I have taken it apart once and there is a screw inside, but I'm not sure if that is how to adjust, never looked into it because the need just isnt there. I ended up using injectors from a '97 because my 91 injectors leaked a tiny bit when sitting overnight and would cause a puff of black smoke on startup. The 97 injectors run much quieter than my 91 injectors did, and I believe they are rated 1# higher (not sure). So if the increased flow does demand more fuel that may just be enough to compensate, then again the computer isnt tuned for it so who knows.

Theres a cap in the back of the 96 plenum, you just knock it out from the inside and the vacumn distribution block fits in perfect. Only 1 of the bolt holes line up though. Mine leaked a tiny bit, I put a new o-ring around the block and it was enough to get a good seal with the 1 bolt. I did that because I have a map sensor in that block. If you dont have the map, you may as well get vacumn from an easier source like one of the extra ports on the TB rather than risk a vacumn leak since only 1 bolt matches. For the coolant port that goes to the TB I used used a good amount of rtv to seal a large rubber stopper in it to stop flow. Has worked like that with no problems for about 1 year now. I'd say do it that way because its easy, effective, and wont cost you more than $1. The other line from the LIM is where the tube that runs to the waterpump housing connects. The other coolant ports are easy, seems like you know what to do with them to get the heater core fed.

other things you have to do:
-'96 wires for the rear bank at least
-I had to remove the valve cover breather spicket on the rear cover because it doesnt clear the plenum chamber. I just drilled the cover and put in a new spicket on the other side, clear of the plenum.
-the 96 TB has more vacumn ports than you will use
-if you dont have the plastic adapter piece for the brake booster line get one (bolts onto the hole shaped like this => () on the TB arm and that is used for the brake booster).
-make sure you plug in the large tubes from the valve cover BEFORE the TB plate, you dont want vacumn on that end of the PCV system
-theres some other stuff, mostly small stuff that youll see has to be done on an 'as you go' process, its been over a year since I did the swap so not every little detail is coming to mind

I could probably help if you have any questions along the way, so let me know!

-john

[dohcfiend]

gotcha there, i snagged all 6 wires when i got the intake. cause i am going to relocate my coilpack as well. and with 12 variable length wires i can't go wrong(hopefully anyway).

i will put those lines be4 the tb just as on the 94 setup.

the brake booster line is still present on the intake, so i will probably use that to connect to the booster. if not i will try my old line...wait a minute. are u saying that that little black think that the line is attached to on the intake is the same as the little black thing plugged into my brake booster on my 94? either way i will grab the plug that goes into the booster from the 96 tomorrow.

I had to remove the valve cover breather spicket on the rear cover because it doesnt clear the plenum chamber. I just drilled the cover and put in a new spicket on the other side, clear of the plenum.

does the 96 valve cover have one, if so i will just snag that, if not the above sounds like a good suggestion.

but the reason i was asking about the pressure reg is i noticed that the line "t'd" into something else and was hoping it wasn't controlled by the pcm. and if it was plugging into a straight vacuum source would just make it max out. but since it works on yours ok i think it might be okay then.

the engine i am putting it on is a MAF setup so i guess i will ignore the wire plug then.

lastly, do i need to swap the iac, and tps sensor?
my iac looks like it will swap directly, but i don't know about the tps.
i will give it a thorough inspection tomorrow.thanks john.ltr.

[jmgtp]

IAC and TPS are the same as for all LQ1 engines. I had to lengthen the wires for the TPS to get them to reach. If you fuss around with the harness you may be able to get the extra few inches and not have to lengthen. The ecm didnt like the lengthening; not sure what exactly went wrong but I think I grounded out somewhere. Ended up running a new set of wires from the ecm to the TPS.

As for the brake booster... the piece I am talking about is a small black plastic thing (its round in shape) that bolts to the TB arm, I believe it even had an internal 1 way check valve - its easy to identify with the 1 large/1 small vacumn port and 1 bolt down the middle holding it on. It was specific to the 96/97 engines, so its probably the piece you see on there. It is the vacumn source for the brake booster. I just did a Tbelt on a 96 a few months back and I cant remember the setup of the rear valve cover breather I know I checked it out too, cause I wanted to compare it with what I did. In theory you dont really need one on each valve cover, as I understand it they are just the 'intake' side of the pcv system; 1 on the front cover may suffice. I *think* the 96 had a breather spicket on the other side (the accessory side of the engine) where the plenum does not hang over it. If you relocate the coil packs I think the best way would be to work the harness out so you dont have to cut splice wires for the ICM. I cut/spliced and I regret it because now 2 yrs later something in my wiring from the CPS to ICM failed and I have to do it again. If you end up splicing be sure to braid the wires from the CPS to the ICM; my GM service manual say no less than 9 'twists' per foot. I got a smaller universal coolant overflow bottle and mounted the ICM and Coilpacks to a plate that is bolted to the Crossbrace (the one that goes from the strut tower to the top radiator support/frame). They hang below the brace so they clear the hood. Plus the accessory belt is much easier to remove without that goofy sized overflow in the way, but I think your 94 has the smaller overflow to begin with.

-john

[dohcfiend]

i have checked out that hole i was talking about plugging up.(the one that goes back to the waterpump). if i just get a 96 metal(instead of the 94) line it looks very close if not a direct fit. ir is there any modification involved?

i am not completely sure where i will mount my coilpack yet. i am thinking about under the tb on top of the tranny. that spot is really easy to get to since i don't have an airbox anymore.

other than the valve cover mod i think everything is about covered.

nope mine has that goofy overflow that sits an 8th of an inch from contacting the drive belt.

the 96 doesn't even have a breather on the rear valve cover. but since mine does i will drill a new one somewhere else.no biggy.

i am also assuming it is a 96 it might be a 97 or 8.

thanx for all your help. i will keep u posted.ltr.

[jmgtp]

The metal line from the waterpump housing to the lower intake wasnt such an easy fit. I had a hell of a lot of trouble but that was because of the air injection lines in the exhaust manifolds which your 94 doesnt have. I ended up using the part that fits into the lower intake manifold and about 1 foot of the tube past that, then I cut it and ran a custom tube to the water pump housing.

On top of the trans sounds like a bad spot for the coil packs. Youre looking at a hell of a lot of heat coming off the crossover pipe and the 96 TB arm is sorta gonna be in the way, the TB is oriented differently then the 91-95 engine and sits further forward in the bay - which also means you will have to likely modify whatever intake tube setup you are using. If you dont have the airbox anymore the better place to put the coils would be on top of that plate that the airbox used to bolt to.

[dohcfiend]

modifing the intake setup won't be hard for me it utilizes 4 in flextube.
1 prob on the plate even when my car did have an airbox it never had that plate. the box was kind of wedged in place.

there doesn't look like anything will get in the way of that coolant tube on mine. as u said no air injection, and no coilpack will be there either.

1 more question what about the egr setup? did u use the 96 solenoid and splice the wires for that connector? and will that tube reach from the exhaust manifold to the new location? and i was thinking about just putting the 94 egr solenoid in it's place, but there is a slight difference in the recirculation hole. the 96 hole is round and the 94 is more of a 1/4 moon shape. will the solenoid function in the different hole?

[jmgtp]

I dont have the egr setup worked out as of yet. I just plugged the hole in the exhaust manifold and put a rubber stopper in the intake manifold. But, since I have to go through emissions I have been working on making a working egr setup. So far I have made a custom egr tube. The 91-95 tube is not bent correctly to reach the 96 intake manifold nor is the adapter the same. The 96 egr tube may work, under the assumption that the exhaust manifold end is the same - meaning same type of fitting and in the same exact location. I didn't have the tube from the 96 and didnt have the $ for a new one so I made one. I have some plans (schematics) to get the obdII 96 egr to work with the obdI 91 ecm, but as far as I know its untested so I wont be sharing them until I know it works. I 'bench' tested it and it worked but I don't know how the ecm is gonna like it in the real world, although as of now it looks promising. The other option, is to make an adapter plate and use the 91-95 style egr. Since I live on campus at UConn (mens & womens nat. champs!) I basically have no time to work on my dohc since its 60 miles away and I'm at home for only a weekend per month. I'm actually going home today for Easter weekend, but I doubt I'll have time to work on it. But, come May, I'm gonna be all over it.

[Anonymous]

This sounds liek it is a pretty complex swap.

Were the power gains worth the time/trouble/money?

I was also thinking of doing the airbox thingy that the Fiero guy did, the one that dynoed 240FWHP on a stock 3.4....Just with longer intake runners for a btter low end. ALthough looks would no be great, performance would be.

I know Bowtiekid did the 96 swap, I bet he could help out too. Might want to PM him. He said ti did little for power, but I have a feeling he may be BS-ing.

Also i'd use 96 injectors, that would eliminate the idle problem plagued with so many 1st gen 3.4s.

[jmgtp]

Well, I can't and won't speak for other people; but on my car, at sea-level, the gains were very noticable. I really can't say if it gained any hp/tq because I have not done a before or after dyno. I can say that the powerband is broader. I guess if you could justify the amount you have to spend to get it done its worth it. I got a good deal on the hardware and spent less than ~$150 USD to complete the whole thing.

[Anonymous]

I am going to do the swap when I put on my P&P heads. 150 aint bad. It seems I need a lot more than I htought. WTB-96-97 top half of motor....

[dohcfiend]

1 more thing. there is a sensor on the bottom of the lim, is the sensor the same as the 94?

[jmgtp]

It is the coolant temp sensor for the ecm. It is the same.