email sent.

 

Can I get a copy too?

anesthes@cisdi.com

I was gonna buy a set of these a while back and have rich @ cruzin performance test them to see what they actually flow. Did you buy the modified ones?

-- Joe

 

email sent.

I'm using the Bosch III, part # 198R53. For L-98 engine.

 

Hrmm.

If you don't mind can you send me the actual datamaster file?

-- Joe

 

where did you read this info?

 

My bad, I edited the post.

 

that part # is ours. as i always expressed the only replacement for an original part is the one thats was manufactured for it. In this case the Multec. Replacing a multec with another multec I don't feel is in the best interest of the owner since the failure rate on these is so high. We needed a replacement that flowed the same as the stock ones and also bolted right in. Secondlly we needed an injector that was available in large quantities so we can sell them for under 170.oo for a whole set. The Bosch 3 fit those parameters and we have made our own modification to the base so they replace the longer multec without any problems. The first video in the sticky at the top of this section shows this injector compared to the stock and some other popular replacements that are used in the L98. You can see in the video that it flows the same as the stock injector, We also offer service on your own injectors as another alternative but, we do not recommend the cleaning or reconditioning of the multec as other companies that only service injectors do. Here is a quote from Jim Linder of Lindertech one of the most respected names in fuel injector service.
General Motors Multecs: These are more likely to be shorted than not! We throw away approximately 65 percent of all GM Multec cores. Each Multec is tested under a loaded (on) condition with a current load unit and a scope. (This test is repeated approximately four to five times per injector from beginning to finish.) Many bulletins have been offered from "The General" on this subject and why it occurs, but in reality it doesn't matter since they are the only injectors that have had this particular pattern failure; other units run for hundreds of thousands of miles without the problem So why opt for this. there is even a TSB put out by the General back in 94 stating not to use any cleaners on these injectors as it will accelerate the failure. So we came up with an affordable solution.. This forum alone has many posts on how these injectors have improved the performance and reliabilaty of the C4. This is what we care about.. We do not care what Rich at Crusin thinks or what Joe Anetheses thinks. If you buy our injectors they will work better than the multec ever did, Thats a fact evidenced by the countless numbers of customers with these.
if one fails we will replace it FREE with no questions, and if there is a problem we will find the fix. End of discussion
Jon Jr.

 

I agree w/the multec not being a good choice. Ultra sonicing an inj. may not be in the best interest for some either. The prices and your policy does make your servcie sound good.
Seeing as I did not bring up competitors or others opinions, I'm not sure why that was pointed out for me.

 

sorry it wasn't for you but from a few posts up

 

Or the fact that I have them installed in my car and it runs and drives fantastic, even though they are not "direct replacements".

Let us not forget about Jon's top notch customer service and that he continuously contributes to this forum in a POSITIVE manner.

mseven, just curious. What would you recommend as a replacement for the original Multecs?

anesthes, I sent you the Datamaster file, what are your thoughts on the data?

 

With out a doubt Bosch's. The type II's were originally rated (lbs.) using 43.5 psi. and are what I have been using. I have been using them because they are good, and it is easy to know which ones(sizes) will support what set-up. As to tuning it also allows me to understand were I need to set up various parameters in the tune (using "x" pressure, inj.constant etc. gives me my base input in the tune).
I do however like the new tech in the III's. My only thought was determining the difference of lbs/size at what fuel pressure becomes important. This is needed to understand what size inj.(lbs.) would equal the existing size inj. at 43.5 psi. (instead of an inj. rated at a higher or lower psi.). Reading their posts gives me the idea that they understand how fuel pressure will change fueling, and will directly effect lean/rich, blm, etc.etc.
BTW, there are a few others aside from multecs I wouldn't use. ACCELS for one a few years ago were a realistically priced replacement. However, there were many here who tried them in the past with out good results...........and no vendor support

 

This looks like a really good buy, but just so I could justify it; what are the symptoms for worn out, clogged, etc injectors? I have got a 94. A high speed miss just past 5500 RPM, is that a symptom?

 

You need to troubleshoot the prob.

How many miles on the engine?
Do you have any DTC set ?
What is your fuel pressure?
The LTx engines are notorious for "Opti" issues.
Do you have access to a scanner and a FSM (IMHO both must haves)

Hopefully others with a better understanding of the LTx motors will chime in.

 

I have to agree. I installed Bosch IIIs from Jon in my 85. The mileage is consistent with the old injectors but the starting and idle greatly improved. Best money spent on this vette so far. And now I have injectors that are sized for the horsepower this engine will put out when I have the money to invest.

 

 

Better get your flamesuit on quick!

 

What's the lowest reliable pulsewidth the III's can handle? I've had some issues with the older "red tops" and "dark blue tops" (30/36) with commanded pulse widths under 1.5msec. Erratic idle, etc. Can the III's run reliably under 1.5msec on applications where you need a TON of fuel at WOT but hardly any at idle.

-- Joe

 

Joe the new SVO 30's that replaced the old school red and blue tops are a world of difference. These Bosch 3 are the same injector except for size (they are actually 32lb in 3 bar rails) that are in all LS1's stock. Gm went to the Bosch injector exclusively in all corvettes from 97 to present. Since I am not a tuner,you will have to try them. Trim your own fuel tables and compare. Don't forget that the old red tops are over 20 yr old tech, I don't think short pulse width tuning of the newer style would be a big chore, the old style were replaced for a reason.

 

Currently I am looking at around 1.8'ish at idle. I don't know for sure yet (not enough drive time)where they can realibly function when doing OL in idle etc. So far I haven't needed to use OL for idle/offidle. (I need to continue in good weather w/the LM etc.) However, I have a set here of the white 36# III's(been cc.d at 43.5 and ended up looking pretty close to the same as the dk.blue top II's) at this point it appears as though some of the offsets may need to be changed, due to the way the inj. seems to respond.....it will take more time before I have conclusive info.

 

I know this thread is a bit old, but I thought I would post up some information relevant to it.

The new-to-me '92 LT1 coupe that I bought last September had, and still has, some definite driveability bugs that I've been slowly working through. With the help of my mechanic, we've addressed a number of issues, and each repair has brought us small but positive results. Over the winter I purchased an Auto X-Ray scanner and had posted some numbers up from it on the "other" forum. In a nutshell, from a cold start in open loop, both (right and left bank) BLMs were locked on 128. As soon as the system went closed loop, the right BLM shot up to 160 and was pegged there at idle, but would come back down under acceleration/driving. The left BLM in closed loop was in the 130 range, give or take a few. My initial suspect was 02 sensor(s) and/or injectors. My injectors all checked within range as far as resistance goes, both hot and cold, and fuel pressure was bang on at 42-45 psi and held there with a fairly slow bleed-off.

Just yesterday, I had both of my 02 sensors and my in-line fuel filter changed. When I drove the car home from the shop, I had my scanner hooked up. Now, in closed loop at idle, both BLMs are right around 110-115 and 120 - 125 while accelerating/driving. I also noticed that with the old 02 sensors, the readings (especially on the right sensor) were kinda' whacky, making changes between lean/rich very quickly at times and very slowly at others. With the new sensors, the lean/rich changes are much more consistant and steady, and I'm seeing actual lean/rich/lean/rich changes whereas with the old sensors it would sometimes go lean and stay there for long periods of time before changing.

The car does seem to run SLIGHTLY better now, and I was able to pass my state's emissions test yesterday with flying colors, however, the idle is still fairly uneven. What I've been calling "bouncy". I just received a set of 22# Bosch IIIs from Jon at FIC this week, and I'm hoping to get them installed tomorrow morning. We're expecting lots of rain here tomorrow so even if I do get them installed, I doubt I'll be inclined to do a lengthy road test. As soon as I do though, I'll get some data from my Auto X-Ray and from the scanner built into the seat of my pants and post the results here.

I'm sincerely hoping to keep our 'Vette for a long time, so it was natural that I would want to get to know how it ticks, but I never, NEVER, thought I would come to learn this much about Corvette fuel injection in my life!

Ron