ECM questions

[tomtom72]

Thank you Kevin for the advice!

Secondly, just got off of the phone with Bill at P & G chevy in PA. These people are very cordial and helpful. I called with the old P/N from the parts CD and Bill chased down the part thru three P/N changes and didn't like what was up. He took my e-mail & phone # and is getting back to me when he is satisfied that he can get me the correct part.

Maybe I expect to little, I don't know. I can only say that P & G makes you feel like they care that you get the right parts the first time! Kudos to Bill and P & G chevy!!

Just thought I would pass this along. Oh and their prices seem reasonable also.
Tom

[Kevin]

While I have had some bad experiences with other parts of the dealer I am going to list, the parts guys have always done me right. Try Tom Henry chevy 724 443 1575 tell them you are with the net/registry (although they will probably figure that out) and they give you a 15%(I think) discount. And try Pete @ 781 953 2034.

[tomtom72]

Kevin and everyone else in this fraternity, Thanks! Truly it is the people and not just the car. The car is nice, we all know that. I learn every day that the people involved with the car are first class and that makes the ownership experience so positive!

P&G got back to me & there seems to be a lack of 90 ECM's in the system for now. I ordered one from AutoZone, they use the original GM P/N's to verify which ECM you need, $266.00 w/tax & free shipping. I'll let everyone know how their stuff is. Oh, GM's new P/N for the 90 replacement ECM is P/N 88961373. I didn't ask the price but I'm sure it's easy to find.

I'm waiting for a reply from RC but I understand their #205 injector is the correct replacement for both 1* and 2* injectors on a 90Z?

Also I have a Q about ingnition Sys Replacement Parts:
OE coils = 40K volts or Jegs has a coil at 45K volts. The pricing is par between the OE & Jegs w/ tax & shipping. Which would you choose?
OE wires vs Magnecor?
I may also R & R the electronics for the ignition system, for preventive reasons, any thoughts on this?

My only reason for all these parts being R & R'ed is I don't have a garage where I can work. If I do this myself I figure to make it a one time event, as much as humanly possible. I understand electronic parts quit when they quit, no warning. I just figure new parts may be more reliable than my 16 year old ones. I'm looking for a garage where the owner would allow me to do this type of minor work; if I don't find one I have to buy labor from one of the local vette shops. Either way, I have to make this count. My own house is a few yrs off yet $ wise. Anyone's opinion would be welcome on any of this!

Thanks again,
Tom

[Aurora40]

Hey Tom, I just want to say, $266 for an ECM just to see... That's about 1/2 way towards Tech-I. Also, this is the whole ECM, right, not just a PROM?

Also, the coil packs are GM/ACDelco parts. You might be able to find a local AC Delco dealer that will sell for the "jobber" price vs. full price. I think they were about $30-40 each from my local place. Part #D545. I'd also be glad to pick them up and ship them to you. The plug wires are AC #628D in case those are cheaper than from GM sources.

Edit: You don't need to pull anything to swap the ECM or PROM, so perhaps you should do these after.

Also, I plan to pull my plenum in the coming weeks/months to swap out wires, get the injectors rebuilt, and patch up the secondary vacuum system. I thought about coil packs, but it doesn't seem like a maintenance item really.

[tomtom72]

Aurora40, Yea I hate to trouble shoot this way. That said I just got a reply from GMpartsdirect.com..."ECM is not in stock. You may have to seek an aftermarket vendor to fill that order..." I don't know what that means except to say I got the same answer about the 1990 style right front LTPWS sensor awhile back.

Anyway, all that B.S. aside, the EPROM is not included with the ECM, and that's from anyone as I understand it. EPROM is a separate P/N at additional cost. I don't remember if I searched the price on a TECH1-A, seems I went to Vertronx's web site & didn't see a Tech1-A, only a TechII or something like that. As I said I bid on one on e-bay & bailed after $750; I think it went to $800+ but I can't say for sure. I figure if the ECM is the problem then I'm okay and if it's not then the injectors I'll order as soon as I call RC.

The other stuff, well when I get my package from P & G Chevy and another vendor I'll have every part of the secondary port throttle vacuum system in hand & brand new. I get the 16 injectors and the ignition coils and wires and maybe stop there; or maybe I buy the "brains" to the ignition system also, heck it's only two more parts. It's alot of $ but then that's new also along with everything else under there. To me having all the parts means only doing the plenum once. In theory I figure another 15 yrs or 13,000 miles of not having to go back under there. Ofcourse I intend to put more use on it so maybe I don't get 15 yrs but I'm banking the new parts will live for some time & milage close to what the OE stuff gave me. I'm not saying my thinking is 100% correct but I think it holds some water?

I figure I can autopsy all the parts after & see what failed &/ or the condition of them at TOD. I know it's not a real mechanic's way of doing things but I'm not in that trade. I'm just some backyard hack!


Tom

[Kevin]

Did you try and contact mid america and places like that?

[tomtom72]

Hi Kevin, Yes I ran thru the on-line catalogues & found one of those guys selling ECM's. Them & autoZone were the same except AZ don't want a core.

I did the on-line order w/AZone, no core charge & free shipping. Both were like $260 - $270 range, so it was a toss-up.

Tom

[Kevin]

I just checked myself. I thought they were less

[Chedberg]

There was something floating over the Net about Lucas Injectors. How do they compare with the RCs? I thought the secondary injectors were different than the primary ones?

[tomtom72]

Hi Chedberg, I do not know much about the injectors, or the rest of the car for that matter! I'm under the impression that 90 injectors are different from the 91-95's, but like I said my lack of knowledge...

I just hope that when I call RC to order the injectors THEY know which ones I need because I sure don't.

RC injectors are made from stainless steel so they don't have rust problems and as I understand the coils are resistant to ethanol mixed in with the gas. The 90 injectors were not designed with ethanol in mind. If I understood what I read the ethanol softens the insulator around the coil and intrudes into the coil's windings. BUT don't quote me on that as I'm probably not correct. All I know for sure is 90 injectors are different. I can see some of the injector pairs in my 90 and I see that the 1* and 2* sit differently in the injector housing, 1* are in further, I think. That's all I know for sure. Also for what it is worth, depending on what grade of S/S is used they will resist deposit adheasion & rust to a large degree. The main advantage of S/S is that it is stable from a molecular and chemical point of view. The metal will not willingly enter into a chemical reaction, therefore deposits & rust will be easier to remove as they don't get a good hold of the metal, they just sit on it. In order to get S/S to react you need a strong reducing or oxidating agent; but that's on marine & surgical grade S/S. The ratio of non-ferrous to ferrous metals in the S/S determines the grade. Ferrous metals, like the OE injectors, do not resist reactions well at all.

Whish I could comment about injectors better but if you go to Mark Haibeck's site there is a paper about ZR-1 injectors. Also in the NetRegistry maintenence section there is a write up also. Sorry but I just don't know enough to answer your Q about the Bosch injectors.

Kevin, I was a little surprised at the results of my search, I would have thought the vette sites woul have been better price wise.

Tom