Alright, I've searched back to 2001 and absolutely cannot find the answer to this question. I am replacing the injectors on my 305 tpi. I've found similar topics. Unfortunately, most of the topics veer off into using 24# SVO injectors and reprogramming, getting the pink top bosch 22# injectors(little to no mention of reprogramming, mostly cause they are going in 350s) or some combination of larger injectors and reprogramming.

My 305, stock injectors are the ever useless Multecs. They are or should be or at least were 19lbs(barring any failures in them). I want a complete, new set of injectors, 19lb ones. I do not want to, nor have the capability to reprogram my prom to use larger injectors, buy a laptop, cables, etc, etc. Can anyone point me to a link, or preferably links with complete sets of 19lb injectors? Preferably Bosch or a similar quality name. I've read mixed reviews of the Accels, mostly bad ones, so I'd greatly prefer to avoid those.

The pink top Bosch 22lb injectors are what everyone seems to use, but I can't find any definative answers on whether they can be used on my 305 >without< reprogramming the chip and if they will cause a rich condition or anything else other than stock happy goodness. I've checked out fiveo motors page and they incorrectly list the Bosch 22lb injectors as being "stock" for a 305 AND a 350, which obviously isn't true. My main problem is, noone, that I have found, has come out and said that the 22lb ones will work flawlessly(not meaning just that they'll plug in and work, but run exactly like the stock 19lb injectors or at least within reasonable tolerances) on a 305 with no modifications to anything at all.

So, what's the verdict?

 

1) The website is wrong lol

305 had 19# and 350 had 22#, but u seem to know this already, just clarifying cause it comes up a lot.

Going from a 22 to a 24# on a 350 will cause the BLm to drop to the 108-112 range and your ecm cannot control it any longer.

Strectching the difference by 3# will make it even worse if u say used 22# on your 305 instead of 19#.

The car will run, but it will be rich and at the ragged edge of ecm control for the fuel if not past it.

Either invest in prom burning or find someone in your area who can. Or take the beating an by 19#stockers (think SVO may make 19#, but I am not sure)

SVO are by far the cheapest and most dependable I have run across and have purchased 2 sets of 24# and a set of 30#.

later
Jeremy

 

I figured there would be some problems with those 22lb ones with no prom modification. I wish I knew someone that could reprogram mine. As it is, I'm buying a whole pile of tools to properly get the intake and everything above off. Flare nut wrenches, distrubuter wrenches, timing light, etc, etc. SVO... I know the 24# ones are considered good, and what you just said. Would they be basically like stock? Plug em in and go? No wiring modifications or anything? Just want to make sure before I go out and buy em. I know the other SVO injectors just plug and go, usually minus the metal clips, but that wouldn't be an issue.

I appreciate the breakdown of the numbers. Even if someone says they've used them without issue, going by the numbers it's just not a good idea and has to be causing some kind of problems. Once I can get the next level of tools, prom programming eq, etc, all this won't be an issue.

This whole getting down to the intake gasket run has pretty much turned into a virtual rebuild of every last item in the way, plus a few others. I think I've spent more time researching every single piece of hardware I'll be disconnecting than I have buying what I need. Now I've found even more, such as the hose from the throttle body to the passenger valve cover. I just "discovered" this last night, thinking it was a 2nd PCV valve, which it doesn't seem to be. The whole top end of this motor is gonna be brand spanking new when I'm done it seems. I'm even considering replacing the intake and runners with stock equivalents, well, ones that have ALL the stock mounting points as I'm leaving everything attached, EGR, etc.

Who knows, by the time I actually get to the work itself, I might have been able to scrounge up a laptop, although I'd only give that one a 5% chance of happening, lol.

 

I've noticed that there are a few places/websites that come up regularly when looking for TPI parts:


advanceautoparts.com
autoeverything.com
fbodymotorsports.com (I may get shot for suggesting this one)
jeg.com
slponline.com
summitracing.com

I am in the process of a TPI/intake rebuild myself, so I've been eating up any info I can find on the subject. I too am curious as to which fuel injector would be best for my 355. I'm not gonna reprogram anything either, so should I stay with 22 or can I go 24 and which brand would be best?

Eric

 

I just bought a new set of SVO #19 lb injectors from Summit for around $220 for my 305. So far I installed the injectors & fuel rail. Working on the rest little by little.

 

Were these the injectors you used?

http://store.summitracing.com/partde...2&autoview=sku

If not, could you please link to the ones you used. Thanks!

No problems with fit and all that, right?

 

Yes, I believe those are it. I can check the product numbers this weekend to verify. The picture is not the exact injector. The #19 lb injectors only have one groove total at the top. I ended up using the retainer clips, just to be safe.

I also bought the GM O-Ring kit, from a Chevy Dealership, $18 - $20. I can get the P/N for that kit also if you need it. These are the blue O-Rings that are mentioned in several posts. Just make sure that you put a little bit of oil on both top & bottom O-Rings before installing them, this helps the O-Rings slide in smoother.

For me I hooked up the fuel lines before I set the injectors into the intake manifold, that way I could more the fuel rail around a little to set the fuel lines.

Torque the four fuel rail bolts down to factory specs. I also replaced my Fuel Pressure Regulator with an adjustable one.

Make sure you have all the gaskets you need before hand and there is an awesome article in the Tech Article section on swapping the inejctors. I have this article out in the garage with me.

I plan on porting my plenum next, so I it will be a few more weeks before I get everything back together and running (hopefully).

PM me if you need more info and let us know how it goes.

 

I'm gonna be going after injectors too soon, and will probably go with these SVO 19#ers too. Since they are 19# I wont need to reprogram the ECM even though they say they are for "High Perfromance" applications?

 

I just checked and that link to summit is correct: FMS-M-9593-C302 for the injectors and I also bought from GM the O-Rings: #12587147 which you need 2 of at $21.98 each. I didn't shop around anywhere else for these, maybe you can get them cheaper somewhere else.

BTW - The injectors fit fine.

 

autozone has gpsorenson o-rings that are 5 or 6 bucks a set. you need 2 sets though.

 

Thanks very much for checking on that part number. It's on my parts list now. This parts/tools list is looking quite impressive now, lol. At least I've bought some of the stuff now though. By any chance, do you have any clue on the following...

Not the size, but the type of hoses used for the pcv valve and brake booster? Looks almost like a fuel line hose, but not certain. There's high and low pressure fuel hoses.

Also, there are 2 hoses coming out the... passenger side of the throttle body. At least one is a shaped hose. I don't know where the 2nd goes, but the first goes into the passenger valve cover into a hard plastic elbow. I tried pulling this hose out to check it out and it's, well, kinda hard now. It seems it has hardened a bit over the years and the elbow won't come out of the hose. Like it form fitted in there. I didn't bother trying to remove it from the tb.

Basically, my question on these is, any idea what type of hoses those are as well? and if there are any part numbers for the shaped one or both? You may not have a clue here like me, but I figured I'd ask since you're on the same job as I am. For that fact, in case it breaks... That elbow too, lol.

I think I've gotten everything covered over a number of posts and barring some hidden item, I think these are the last I have any questions on.

 

That hose on the pass side valve cover is the air breather for the engine. Basically, it sucks air out of the top of the throttle body into the engine, so the PVC valve isn't making a bunch of suction. When I installed mine, I just got myself a hose with a 90 degree bend in it, that was long enough from Napa, then for the connection to the valve cover, I just gutted an old PVC valve, and used that.

Works well

 

The larger hose coming out of the throttle body is for the coolant the other is a vacuum hose, if I remember correctly. I'm also doing a thottle body coolant bypass (check the tech articles for more info) and went to the the local auto parts store and found coolant hoses with 90 degree bends to make the bypass look cleaner.

I also replaced my PCV valve and rubber grommet that the PCV valve fits into to. The hoses are vacuum hoses - 3/8 for the PCV and 11/32 for the brake booster. They are thicker and stiffer than fuel line. It's up to you what you want to use. I used vacuum hose. I had trouble finding the brake booster vacuum line. I tried 3 auto parts stores here and ended up buying it from GM, but they didn't stock it so I had to buy a whole roll! You only need about 18 inches of the hoes, so I have plenty! lol

So if anyone needs any, let me know.

Also make sure you soak all the bolts with PB or something before removing them and clean out the Torx grooves the best you can before removing. They strip very easily. I am replacing all the Torx bolts with a kit from ARP - Stainless Steel Hex bolt kit for TPI cars. Should be here this week.

Keep us updated.

 

lol, if that brake booster hose was that hard to find... Let me know how much you'd charge. I'd like to get some of that. Definately a bit more than the stock length so I have some room to play with. Let me know what you're asking.

As for the bolts, one of the sponsors sells a complete set of allen head bolts which I'd figure are far tougher than the torx ones. Some of them, like the thermostat I'd feel much more comfortable replacing on the just in case side of things. I picked up some of the tools I'll be needing this weekend, flare nut wrench set and a really nice timing light. Next is a work light on a pole/stand. I definately know I'll be doing this late at night. Way too hot to be doing it at noon. Also a fuel pressure gauge. After those 2, I'm sure I've covered the most expensive tools and have the rest I need, then comes the rest of the sensors and parts I'll be needing. But definately get back to me on the hose. and keep tossing out the updates on your progress too, it'll be of great interest to me on all the little details. Thanks for the information so far, it's greatly appreciated.

 

I sent you a PM about the hose. If anybody else needs any of the GM brake booster hose, PM me.

I also saw that bolt kit from TPIparts.net. I have a bad taste in my mouth right now for both Torx and Allen head bolts, that's why I ordered the hex bolts from ARP. I'm hoping they should be harded to strip. In any case, you can also get the Allen Head bolts at a hardware store. Look for the metric bolts size 8mm x 1.25 and you'll need several 30mm, 40mm and I think 25mm length bolts. Take the old ones so you can match then up.

I'm the original owner of the car and this is the first time the plenum & intake runners have been off. Getting the old gaskets off was a royal PITA. Be careful with the aluminum surfaces since they pit easily. I ended up using a Gasket Remover spray, a razor blade and lots of elbow grease.

I only have time to work on the car for a few hours on Saturday afternoon, so its taking me a while.

This past Saturday I was matching my gaskets with my intake runners, using my new Dremel tool. Next Saturday, I want to port my plenum, or at least try to.

Make sure you have something to release the tension of the serpentine belt and loosen up the alternator and swing it out of the way. No need to disconnect any wires from it. This will allow easiler access to the fuel lines. I used a 3/4 ratchet/pry bar. It fits into the square whole on the belt tensioner.

Put something under the car to catch the coolant when you remove the throttle body coolant hoses. Don't forget to disconnect the battery. Some folks say to only disconnect the negative cable, I did both and then put the battery on a charger since its been sitting for a while.

Later

 

hah, too bad you don't live closer, I'd most likely help you out with the work. Wouldn't hurt to get a trial run for myself, lol. I had the plenum off before and one of the runner gaskets was stuck to the plenum so it was fun scraping it off for a while. At least the throttle body and one runner gasket are new. That'll save some time with scraping. I'm getting a gasket scraper though at Sears. I figure the extra leverage will make it much easier, especially on th engine itself it any intake gasket remains there. It'll be fun fun just cleaning it all, gaskets and general engine dirt.

I bought some kind of small detail brushes, angled and metal and bronze ones. It wasn't easy cleaning the inside of the plenum though, but using all available openings in it, I managed to get it quite clean, well, it was still discolored before, but no more of that oily gunk.

I figure allen headed bolts would be tougher than torx, plus they'll be new and I don't plan and trying to be hercules torquing anything down. Really, I can't say I've ever torqued down any bolts at all. Just go with, hmmm yeah, feels tight enough. I may do so with the intake bolts, but none of the others. I just can't say I've ever had a bolt come loose that I've tightened, ever. So hopefully those new allen bolts will do the job nicely.

 

That's great that you haven't had any problems so far with any bolts and thanks for the offer of help. When you look at the intake runners on each side, two runners sort of come together in the front and two in the back. There are bolts under each set of two runners, so 2 on each side. These were the toughest bolts to get to for me. I cleaned the recesses out somewhat, but I could never get a my torx driver to sit good no matter what extension/universal joint I tried. Now being on there for 15 years didn't help either! So I soaked them all with PB for a few days before hand. So I was lucky to get them out, but they took a beating and I didn't want to go through that again with the Torx or Allen head. That's just me. My new set of ARP hex bolts came today, some that is the way I'm going. You have to be careful when tightening bolts with these aluminum parts.

Here's another tip, there is one bolt on each side of the runners that you have to get to from the other side of the runners. For example, the driver side runners have a bolt that you get to up by the distributor while on the passenger side, you get to it by the thermostat.

Hope this helps

 

I think I know what the problem is. I was looking up hex socket sets on Sears and found some hex sockets with super long hex ends on them. I mean they look like 3+ inches long. I figure this is what they used in the factory with the torx sockets.

Anyway, did you try to get at them with the valve covers off? The covers look to be a bit in the way and maybe removing them would help get at the outside bolts?

Eh, just pondering out loud before I have ottom bolts? I'm taking the valve covers off anyway to replace the gaskets so I'll find out soon enough I suppose.

Hmmm, if only I had my own 1991 Firebird factory assembly line with a reverse switch.

 

Taking the valve covers off was my last option. I had enough stuff coming off already, so I was trying to avoid that.
I suggest unplugging and marking the fuel injector plugs and moving that wiring harness out of the way. That gives you better access. If I still couldn't get to them, I was planning on buying just a short T-40 Torx bit and try that or getting another T-40 socket and cut the bit off to make it shorter. I was able to get them out without going through that.

If you plan on taking the valve covers off, then you should be good to go. Just clean out the recesses and get the Torx bit to seat straight and that should get them off.

 

one of the torx sockets that are about 3-4 inches long works beautifully for those lowest runner bolts. had mine off several times and didn't have to remove valve covers to get them! short ones don't work as the runner interferes with them or a universal.

 

Finally got the car running with all the following changes:
- new 19lb SVO injectors
- TPIS AFPR
- plenum ported
- TB coolant bypass
- new vacuum hoses
- new PCV & grommet
- new MAT sensor
- new IAC
- timing set
- TB cleaned
- intake manifold bolts removed, thread sealant applied & retorqued
- No torqx bolts (my choice)
- All new gaskets
- Set idle (min air & TPIS)

Car is running pretty good, but needs some fine tuning. I have the fuel pressure set at 46psi (GM had these as 41 - 47 psi), so this may be a little high for now. What fuel pressure is everyone else with a AFPR on a 305 using? (I guess I can search on that). No changes to the PROM. The idle is the only issue. It has an erratic idle after the car has been driven a while, sits for an hour and I drive it again, the car idles too low and stalls. I start it back up and rev it and its ok, until the next time I need to stop. I set the min air & TPIS, the IAC is new & the TPIS I replaced last year for this same issue.

later