after years of working on gm cars with multecs I am convinced more than ever that they are the root of many of the drivabilaty problems with TPI. There is an epidemic of these failing for many reasons. The most common is the inabilaty to handle alcohol products especially ETHONOL that is being put in our fuel. This video shows how a multec fails while running. The second video is our recomendation to solving the problem before you spend unnessasary $$ tracking a problem that there is no trouble code for. Injector Coil resistance must be in spec in order for the injector to perform properly.


this shows you how to ohm check your injectors.. do it cold then hot

 

really really great video ...gives a real understanding of how they work and how you can ohm them yourself and they're ok ...untill they get hot and then the problem begins.

Thanks
Jason

 

And another good video from you. I jumped when you used the hammer. But it did appear to be a "Vette hammer" so all is good. Got to get back up there to see you soon. Take care.

Joel

 

Another nice video. I put new LS1 injectors in my 87 about 50000 miles ago, so I hope they are good for a while.

 

Yeah, the hammer bothered me too, lol. Should I be tapping my injectors a few times after I pop them in? ; They haven't leaked yet and I don't.

Great Video!

 

John,

Thank you for the video; very informative.

I do have a couple of questions for you. In your video, you mentioned that the injectors are off a 1990 vette; are these the original injectors?

If that is the case, you are talking about a car that is 18-years old; how many miles did the car have on it?

What is the typical life span for a Bosch Injector; is there such a thing?

I had over 115K on my 96 before I replaced the entire engine, drove the car extremely hard, and never had an issue with my stock injectors.

I also had a set of Multecs in my new engine and never had a problem with them either. I swapped them out only because I needed a larger lb injector.

Don't get me wrong; I am all for the best products available on the market, will only install the best products on my car (subjective, of course), and it appears that the Bosch Injectors are a great product.

However, I am a bit curious if the problems that you are experiencing would be the same for the Bosch injectors under the same circumstances?

Thanks in advance,

Glenn

 

what a diffrence. how do i know what my injectors are, 1990 tpi. and is there a link to buy the ones he recomends?

 

I was lucky enough to get a set of injectors from you just before you started posting the videos. All I can say is that my car is much stronger now than it was before I installed your injectors. I had already switched out the Multecs for Ford pinktops and I still get better performance from your injectors over the pinktops. Plus, yours are a heck of a lot quieter than the pinktops.
Anyone who is considering an injector change would be smart to get them from Jon.

 

who is john, do i have multec, and approx how much is a set?

 

Cool. Hey Jon, what's the deal with those spacers we talked about?

 

please don't hammer injectors.. Just wanted to show that they were all in..

 

glenn the mutec 1, which is the one's that are failing were used in every gm line from 89-late 93.. the multec 2 used 94 up were a self cleaning design without the epoxy seal that is breaking down in the multec 1. so your multecs in a 96 should last as long as the vehicle plus. However, the self cleaning part is not really true. The filters get clogged and hinder the performance of the injector. We service those injectors. As far as the longevity of the Bosch injector. According to Bosch they are designed to outlast the average vehicle engine 5 to 1. We warrant these for three years and have been selling them for over 20. We just think they are a great product with super quality. The injectors in the video are original injectors in a 62,000 mile 90 vette. The customer spent a lot of money trying to get the miss and poor acceleration out of his engine. He called me to ask how we can service his injectors. He sent them and you see the results. His car will run fine after the new injectors are installed. Using these I felt was a good example because most of the cars still have the original injectors in them with owners refusing to believe it's an injector causing the problem due to poor diagnosis.

 

thanks, pm'd.

 

John,

Thanks for the quick reply; it definitely seems like you made a great impression with the fellow forum members. Keep up the great customer service.

The next time I am in a market for new injectors; I will definitely give you a call.

Glenn

 

Awesome videos Jon, really shows whats up with these multec's.

I can't wait to get the ones for my LT4.

Anyone wondering, don't contemplate it or wait for them to fail and give you headaches. Just call Jon and get hooked up.

 

Jon is the owner of FIC injectors, he started this thread,,,,,, I don't know, what year is your car? Call Jon for a price quote.

 

Thanks for sharing the video. If my '93 starts acting up, I know where to look first.

 

You use impedance and resistance interchangeably and that is incorrect. While everybody has an ohmeter and gross injector coil failures can be found by measuring resistance, this method is really a very poor way to test injector coils. An ohmeter cannot find a coil with a turn to turn short and a coil failed in this manner will not allow an injector to work properly and also early C4's which have each bank fire together, an injector with a turn to turn short can make a whole bank not work properly. A much better test of injector coils can be done with an impedance bridge which measures a coil's inductance and the,"Q". I found a defective injector in my 87 vette this way, the bad injector had 1/2 the inductance and 1/2 the Q, but it had identical resistance as all the other injectors.
Injector coils are low Q coils and the bridge should be set up as a Maxwell bridge which is an inductance bridge meant for low Q coils. You can easily make your own bridge circuit or you can buy an old Heathkit impedance bridge on ebay.
I bought an old General Radio 650 bridge a long time ago to measure capacitors and inductors long before I owned a car with fuel injection, but it came in handy.

OH, watching them spray and measuring their output volume blows the doors off electrical measurents. Thanks for the video!

 

good point.. not being an expert in electromagnetics, I can tell you that the average corvette owner is not even checking the coils with anything. Most repair shops don't either. Your 87 did not have multecs. It had a Bosch injector which was very rarely diagnosed with a bad coil. The multecs are different. The ohm meter will tell you quite clearly if your Multec is going. The design of the multec 1 has a design flaw. It allows fuel to seep into the coil housing. The Bosch does not have this flaw. With this being said, once the coil is shorted it should show up by virtue of a simple ohm test. All I want to stress here is the importance of at least testing these somehow in your own garage. If you read all the posts like I do on the symptoms very few replys include testing the injector electrically. Untill recently. Replacing parts is not my thing. Eliminating what is not broken will lead you to what is. There is no real test besides fuel pressure to see how the injector is working in the vehicle. Building a home made impedance bridge is a great idea. However, I personally do not think most of the guys will actually do it. So the ohm meter for $9.95 at radio shack is the alternative.

 

Last Multecs I had from a couple of GM cars went to the heap of scrap metal in one of our yards. I'm sure they will be part of a water faucet one day. But anyways, great demonstration!!!