2seater

You are probably lean, not rich. The smell can be eye watering likely caused by a lean misfire. Check your vacuum modulator on the transaxle also. Burning transmission fluid cases a nasty smell (ask me how I know ) A couple other causes for lean, aside from the O2 sensor, are vacuum leaks and low fuel pressure. There are other things to check as well, quality of spark, cables and plugs, MAF (give it the tap test). These are all low or no-cost things to look at.

I would like (3) each please. Paypal + fees sent to Nancy? I appreciate your effort on this one. I have looked for them before and had no luck.

I have never heard what you describe but I have always felt something somewhat similar, usually at middling type speeds, maybe 35-55 mph. I have tried watching the injector pulse width to see if the DCFO, or Deceleration Fuel Cut Off was activating. I never found anything conclusive but I assumed this is what is happening.

If the IAC is new, I would suspect this issue has been going on for a while. It still doesn't hurt to take a look inside to see if the passage was cleaned properly. Padgett mentions the stainless steel screws which are non-magnetic, take care with them. Check also for vacuum leaks, particularly the PCV system which is on the passengers rear of the raised portion of the intake manifold. It is buried under wiring harnesses so is easy to overlook. Usually small vacuum leaks will raise the idle speed but larger ones will cause stalling, and you may be able to hear it. Check all of the hoses closely, including the ones at the rear of the vacuum block going toward the firewall. If it takes several minutes for the problem to appear, it possibly is when it goes into closed loop operation and one of the sensors is acting up. Any codes?

Missing the front upper engine torque strut too and the corner bracing from the strut tower to the front header panel? It looks like the upper mounts for the fan are floating since the upper mount for the radiator is missing.

It is supposed to be a temporary situation only. I am doing a different configuration for the turbo setup, hopefully simpler than the original setup, which I still have. As you well know, once the engine is boosted, it's hard to go back

Search for posts from F14Crazy. He did exactly that a few years ago. A lot of detail on the work he did is included.

Good deal. Always good to hear what the solution was for future reference. Ciao

There is no way to check the fuel pressure through the CRT. This can only be done with an inexpensive test set. Harbor Freight sells one that works just fine. Typically the most common cause of poor mileage is a slow, or defective, O2 sensor, but beyond that, there are many things that can cause a problem. Padgett points out a misfire will cause problems that the O2 has no control over, and will drive you crazy. The reverse is also true. A defective injector may cause a mixture that the plug can't fire consistantly. Indirectly you can watch the Fuel Integrator (short term correction) and Block Learn (long term) to see what the ECM is trying to do. Readings that are substantially above 128 indicate the ECM is trying to add fuel, and under 128 indicates it is trying to lean the mixture.

Are you sure you have adequate fuel supply (pressure). I agree the balkiness of the engine is more noticeable when locked up in high gear, and is likely a misfire, however, a lean fuel mixture is harder to fire than a rich one. When you back off the throttle while cruising it may be unlocking the converter, lessening the feel of the miss, which returns when it re-locks. If you suspect the secondary ignition, you could try gapping the spark plugs way down, like .040" or less to see if it improves the feel of the engine. This is only a bandaid if it helps. You should be able to see what the MAF is seeing, as well as other sensors, while running with diagnostics operating. Unfortunately fuel and spark are two items that don't set codes directly and are only indirectly displayed in diagnostics, such as Integrator and Block Learn, plus O2, for fuel delivery as Padgett mentioned.

The back driver's side is #6. Just so it gets connected to the proper coil

I have not actually tried the GN heads on a vin C but the layout of the intake ports is different, so I do not see how that is possible. The GN has paired intake ports on each bank, similar to a smallblock Chebbie and the later engines, AKA 3800's, do not. I think there are other differences as well but the biggest one is: the 3800 heads flow better than the earlier design. See Stan Weiss website for flow data on many different heads. A variation of the later model heads was used on the turbo Firebirds in 1989, with a GN lower end, so I imagine there may be a basic physical matchup, but I imagine a hybrid cam of some sort would need to be fitted? The GN cam won't work in the 3800, as it was a flat tappet design and still had the drive for a distributor at the front. The total 3800 engine is a superior package, IMHO, although the ultimate strength of the GN block (high nickel content), is probably better. I remember one of the GN guys from many years ago tested the early 3800 blocks to see if they would be a viable replacement for the more rare GN variant. He found the stock bottom end was good to 500 hp. before it showed it was at the limit. There is very little difference between the S/C and N/A early 3800 shortblocks, so a moderate amount of boost can be added to the base engine relatively safely. There is some evidence that the connecting rods are different but I have not seen verification they are actually stronger. They would carry a different part number due to the full floating piston pins. It won't be a race engine without extensive work, but if used with reasonable care and restraint, the stock parts are capable of moderate increases in performance.

I was already running a 160* thermostat with a premium fuel chip with additional timing and other mods. I don't think any change from the standard thermostat is needed with the minor change to the engine. The high temperature stock t'stat aids fuel mileage, the low temp. aids full throttle power production but the 180* seems to be a good all around compromise. This was all done 12-15 years ago and many changes followed, not all a rousing success

The effect of slightly larger capacity has very little effect on any operating system. The .020" overbore (.5mm) increases capacity <1% and the system has far wider operating latitude to adjust, so it is a non-issue. Increasing the compression ratio has a small benefit, but better to leave it as is, or lower, if adding boost. Unless the one I have is a fluke, the '88 cam I have is a bit more aggressive than the later vin C cams so the offer an '88 engine might be a good consideration. The image is crude but is a graphic representation of the cam measured in the same engine at various lift points. The larger lobes are the '88, the smaller is from an '89.

When I had mine done several years ago, it was bored . 020" oversize for 233 cu.in. total. I "believe" the limit is .040" oversize, or 3.840". There are supposed to be stroker kits available or the crank can be offset ground to increase the stroke but would require different rods. I'm not sure how much work would be involved since there are six discrete rod bearing surfaces due to the split pin design. If you do go the rebuild route, watch the compression height and dish volume of the new pistons. Many replacements are "destroked", assuming the block will be decked and the dish may be larger, both of which will lower the compression ratio, even with a larger bore. Now that isn't all bad, it works very well if you add boost. I used Silvolite hypereutectic pistons for a vin "L" which are a little taller than stock (9.1:1 compression ratio) and I did not investigate OEM replacement pistons which may be the best direct replacement depending on cost.

The actual fitup should be no problem, however, the vin "L" has a hole in each head for the integrated PCV system. I am pretty sure the L67 S/C manifold will have the same passages. The intake manifold is longer at the mounting flange to allow for the additional hole at opposite corners. The "C" head is flat in the correct area so the holes can be added before installation and you must use the S/C intake gasket. If the holes are not added, a conventional external PCV system can be added with some ingenuity.

Typically, an intake gasket leak will show up in the oil or externally near the corners of the intake. It is fairy common for the aluminum intake manifold to corrode around the water ports at either end and it is possible for it to leak into the intake port adjacent to it but two seals on the gasket would need to fail for it to leak directly into the port. Does the coolant appear to be contaminated with exhaust or oil? Do bubbles appear in the radiator while running? My FSM recommends cooling system sealer be added when the coolant is changed. Not that I am recommending that at this point, but I suspect it is a preventative measure due to galvanic corrosion in the aluminum.

From a previous thread, it sounded like you were considering doing a performance upgrade, so the S/C engine seems like a natural. I don't know of any way to upgrade performance of a N/A engine for the relatively small difference in price (maybe nitrous). There will be some programming issues to deal with, but that would be true for any upgrade, and the S/C installation has a fair amount of support. The S/C may need some service if it is still original. Ryan @ Sinister Performance/GMTuners does lots of this type of installation into Fiero's and can certainly help with the programming. My $.02

Definitely brass. Do the ones in the back inside the bellhousing area too. No headaches for the future.

Hmm, that's odd? I have done the engine more than once, by itself, and the hood doesn't even have to be removed, although it does make it easier. I believe the procedure is outlined in the FSM? My hat is off to you if you managed to get both out the top as an assembly.

Grease the tap and it will hold most of them and fish out what you can find after the holes are tapped. They are already the right size so they do not need to be drilled. I know it isn't perfect, but anyone that has pulled the drain plugs, or core plugs, on the water jacket will find lots of misc. crud. I did have one hole, the large one, that was slightly mishapen, so the plug was installed with JB Weld rather than pipe dope. Never a problem.

I just eliminate the coolant pipes altogether by tapping the ports in the manifold for pipe plugs, 1/4" for the top one and 3/8" (if memory serves) for the one with the paper gasket. Maybe not what you desire to do, but it makes it vastly easier to remove the throttle body. Never a problem even in November in WI.

Is it worth the hassle? I guess that depends on wether you enjoy the challenge and fiddling with things, or not. The fitup of parts was done using photographs, careful measuring and a spare engine hanging on the stand. I'm no ace welder, and everything was put together with a 110v Lincoln wire feed welder (MIG). Most of the piping was made from a couple of sets of stock manifolds, cut apart and various bits of regular exhaust tubing added. All piping and turbine housing is ceramic coated, so the type of pipe used is not terribly important and some fancy header style of hookup is not needed. A plain old log style manifoild works just fine. The power increase is infectious and with a turbo, the faster it goes, the faster it wants to go. Tuning was the biggest issue, and was never really solved since the MAF sensor goes over the high limit very quickly. I looked at my old test run records and the MAF reaches maximum flow of 170 gm/sec in as little as two seconds and under 30 mph from a dead stop. A turbo is not directly linked to the engine and primarily responds to load so the tuning process will take a bit of doing. The chip changes from Ryan @ Sinister Performance did make the car very driveable and I put over 20k miles on it in turbo form. Now that the boost gauge stops @ zero, I do miss the easy surge it used to have. I am hoping the new single manifold setup will provide what I desire and will greatly simplify the addition of a turbo without a bunch of plumbing changes, plus I can address some of the issues from my first attempt. The easiest route for increased power, and the way a GS version should have been built, would be to drop in a SC engine as has been done plus most of the tuning issues are known since this was a factory option on other models.

Others have done exactly that, using the stock system and crossover as the feed to the turbine. It looks like a no brainer, but getting the exhaust back out and down the rear of the engine is a challenge. It is best to re-orient the #6 exhaust to the new exhaust flow pattern but is not critical. I admit I gave up trying to figure out how to route a second pipe through the area at the rear corner of the engine and avoided the issue altogether. The O2 sensor must also be relocated to the outlet from the turbine (somewhere in the downpipe). I am told the high backpressure ahead of the turbine affects the O2 accuracy. The throttle body is in the stock location and my first installation did not use an intercooler so the compressor blows directly at the MAF/throttle body. Lag was not a problem. It would reach full boost during the time the transaxle took to downshift. Too fast really, given the relatively weak transaxle. I tried the MAF in two locations, stock, and also in a fabricated adapter ahead of the compressor. No real difference in performance except the small MAF on the inlet had the effect of slowing the boost buildup. Easier to blow through a small opening than to suck through it. My main concern was to get a better handle on the actual air temperature entering the MAF, since there is a chart in the ECM program that uses it to modify timing and the MAF response. My latest attempt uses a vin L throttle body, adapted to the stock intake, and a modified intake air sensor located inside the throttle body so it sees actual air temperature at the throttle. There will also be an intercooler which could be added to the original installation with some additional work. I "think" the dead cam will make the single manifold feed to the turbine feasible since there is NO overlap above .020" tappet lift, even with the slightly more aggressive '88 cam. It has been done before and Saab actually had a V6 with that style of turbo from '96 - 03'.

My installation was a single turbo, an amalgam of a few turbos from the Garret T3 family. The photo with the black ceramic coated piping is my installation. The rear manifold was scratch built with a crossover around the front of the engine and connecting to the stock front manifold between #1 & #3 exhaust. (That's why my my coil pack is rotated 90deg.) The downpipe was actually a two piece afair constructed so the turbo assembly could be removed and the stock crossover pipe would drop back on so the engine could be operated in N/A form (no confidence for a first attempt)? The other photo is one of the original factory Reatta turbo installations. I have more photos but cannot find them at the moment, but, there have been previous posts on this forum with the original magazine articles about those cars. The actually made a RWD high boost (read GN) engine as well. My next installation will be a single turbo powered from the front manifold only. I actually have it all ready to go, ceramic coated piping is done, but have lacked the time to complete the installation. I believe this will work well for a low boost, 8-10psi, installation and will make it vastly easier to install a bit of boost without reinventing every thing else.