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Thanks Joe..... I was able to cross reference the number stamped on the injector itself and the best I could come up with as far as brand, was GM or AC. They were referred to as both. Other part numbers were:
217-231
17111418
The actual part number stamped on the injector is 5235211
Ok, so it says there the resistance is 12 ohm.... I assume that is the cold condition reading.? I have only checked mine hot.
Thanks Joe..... I was able to cross reference the number stamped on the injector itself and the best I could come up with as far as brand, was GM or AC. They were referred to as both. Other part numbers were:
217-231
17111418
The actual part number stamped on the injector is 5235211
Ok, so it says there the resistance is 12 ohm.... I assume that is the cold condition reading.? I have only checked mine hot.
fyi that 12 ohm......that is a Ford/Bosch 14lb injector. Apples to oranges.
You know i never did. They were all in the upper 17s warm.
Ima' check mine when I get off work tonight, just so we have a cold/hot base line for this type of injector. Im also gong to try changing the timing a couple degrees too. Im at 5300' altitude....
FWIW, here's a pic of the GM multec vs EV6/3rd design injector (commonly known as boschIII).
on the subject of boschIII's, here's a pic of the 3 current bosch designs --
EV1 or first gen bosch were used on early TPI cars. not sure when GM switched (backwards) to multecs. considering the technology at the time, original EV1 bosch injectors were, and still are a good design. I don't know who holds the design patent, but EV1 injectors are licensed and currently manufactured under various nameplates. not 100% positive, but i'm thinking there are 4 major EV6 designs. don't know the original EV6 applications, if any, but 2nd, 3rd, and 4th designs are commonly used. aside from size and design improvements, the major difference with the original bosch injectors are the number of fuel discharge ports - EV1 - single, EV6, 4-hole discharge port.
Not exactly true. I have had 4 port EV1 injectors. The early FMS 24lb blue tops and orange yellow top with a BRASS base 19 lb were EV1 with 4 holes/ports as I’m sure many else were.
Not exactly true. I have had 4 port EV1 injectors. The early FMS 24lb blue tops and orange yellow top with a BRASS base 19 lb were EV1 with 4 holes/ports as I’m sure many else were.
not doubting you, but I can't see how an EV1 injector can have 4 discharge ports due to the characteristic design of the injector nozzle.
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damn, it took a while, but I did find this...
Ok you made go deep into my toolbox from almost 20 years ago from my push rod 5.0 days. These are OE 93-95 19lb.Lightning Injectors rumored (i cant prove it) to flow 21lbs. These were also marketed as FMS 19lb injectors (allegedly balanced). If you had a speed density car that was modified these were the ticket. BTW all 8 cost me $60.00 new!
not doubting you, but I can't see how an EV1 injector can have 4 discharge ports due to the characteristic design of the injector nozzle.
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damn, it took a while, but I did find this...
guess you learn something new everyday -
that first injector is a ‘pintle’. Decent for fuel economy in the day but not a ‘performance’ injector.
I have the EV1 style in my 86 late (aluminum heads). I was thinking of replacing them with the newer style injectors with the multi hole ports as I read all over this forum that they give a better idle etc. mine ohm out fine, and I removed all the filter baskets etc as I was originally going to refresh them myself. the car ran fine as far as fuel delivery goes, was a bit hard starting but with 160K a couple of cranks doesn't surprise me and doesn't bother me. I was set to upgrade but now budget concerns are kicking in again so I may go back to the originals. I can get them flow tested after I replace the parts pretty cheap.
I am starting to think that before I upgrade my L98 to a full roller etc, an LS swap may be more fun in the long run.
I have no idea if my PO installed these or if original. They look similar to yours, 81c3. They are resemble the EV1 except for the pretty color and different end.
Note: where the orange washer is near the tips, that's where the orings go, hadn't gotten around to that in the pic.
St. Jude '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-‘19-'20-'21-'22-'23-'24
Originally Posted by 81c3
Doesn't the cold start injector come into play when the engine is cold, and not hot? Sounds reasonable.... but I really am not sure.
Yes
Originally Posted by 81c3
I think timing could be an issue.... Today I hammered it a few times and could hear pre ignition/ detonation under heavy load. I actually use premium all the time....
Premium is not necessary in the low compression 86 L98. Just tossing money out the window.
Originally Posted by 81c3
Ok, so what injectors in my 86 L98???
Multitec's
Originally Posted by 81c3
Update: So just for the record, all of my injectors ohm'd between 16.1 & 16.5 tested cold.
If you're going to keep the car, buy a set of Bosch III's from FIC.
Replace the fuel filter and run the car before changing the injectors to prevent contamination after replacing the filter.
Open and inspect the FPR. If there is fuel on the vacuum side replace the diaphragm.
You can check for fuel presence by pulling the vacuum line and checking for fuel.
My experience with the 86e was she ran better overall. Idle and throttle response were improved. I didn't notice a power change as much as she ran very smooth afterwards. I did add and adjustable FPR cover that allowed for some max pressure adjustment that helped throttle response greatly.
Premium is not necessary in the low compression 86 L98. Just tossing money out the window.
Multitec's
If you're going to keep the car, buy a set of Bosch III's from FIC.
Replace the fuel filter and run the car before changing the injectors to prevent contamination after replacing the filter.
Open and inspect the FPR. If there is fuel on the vacuum side replace the diaphragm.
You can check for fuel presence by pulling the vacuum line and checking for fuel.
My experience with the 86e was she ran better overall. Idle and throttle response were improved. I didn't notice a power change as much as she ran very smooth afterwards. I did add and adjustable FPR cover that allowed for some max pressure adjustment that helped throttle response greatly.
Thanks Coach! The only question I have though is that you say the injectors are Multecs.... Everything Ive read so far and part numbers are saying Rochester, AC, GM.... Seems the Multecs werent used until later MY.... What gives?
On another note, talking about the cold start injector.... When I start the car cold, it fires up in a 1/4-1/2 turn of the key.... Idles as it should and gradually comes down to 650-700..... Now... while the engine is cold, if you even think about blipping the throttle or giving it gas it stumbles terribly.... Once its warmed up and the idle settles at normal rpm, it runs perfectly. Is that cold start injector related or something else? Not a big deal, because I dont jump in and drive anyway... I always let it warm up before driving.
Premium is not necessary in the low compression 86 L98. Just tossing money out the window.
Open and inspect the FPR. If there is fuel on the vacuum side replace the diaphragm.
Wouldn't it be better to scan it with different grades of fuel so you can see if the it is necessary and if the station you think is good is really selling the good stuff or not?
For $50, if it is old, maybe it might be a good idea to replace it when you are doing injectors just so you don't have to go back in? IDK how difficult it is to do but I have a HSR which is easy. On my Superram, it is more difficult so if the plenum comes off, the regulator gets changed. How difficult is the job? I can't remember anymore.
Thanks Coach! The only question I have though is that you say the injectors are Multecs.... Everything Ive read so far and part numbers are saying Rochester, AC, GM.... Seems the Multecs werent used until later MY.... What gives?
On another note, talking about the cold start injector.... When I start the car cold, it fires up in a 1/4-1/2 turn of the key.... Idles as it should and gradually comes down to 650-700..... Now... while the engine is cold, if you even think about blipping the throttle or giving it gas it stumbles terribly.... Once its warmed up and the idle settles at normal rpm, it runs perfectly. Is that cold start injector related or something else? Not a big deal, because I dont jump in and drive anyway... I always let it warm up before driving.
Either way, they are kinda of old and a reman set is so cheap, I'd do it just to get the crud out. See image below.
I'd do a couple of things. Send the Cold Start Injector out for service since they do have build up. Next, check the coolant temperature sensor. Scan it so you know what the ECM sees and hit the sensor with an infrared thermometer so you know that it is somewhat consistent. What you describe could be the injectors not doing the job right or the temp sensors are not quite right or the IAC isn't as good as it should be. If it is the IAC, the cure is to clean it and if that works, life is good. Take the TB off. Remove the top plate, the IAC solenoid and the IAC housing. Clean passages. Clean the IAC pintle with a gentle spray of brake cleaner and GENTLY wipe the pintle off. Reassemble with fresh gaskets. Also, check the IAC counts with the scanner once it has reached stable operating temps and everything but the motor is off. Should be around 20 to 30 counts.
Premium or 91-93 octane is by design harder to ignite than Regular 87. The lower octane fuel ignites quicker which aids in start up. You want to use the recommended fuel. The stock L98 all had low enough compression they could use regular. Using premium can cause delayed starting, engine will start but not as fast as expected. LT1 had a jump in compression and premium was recommended.
11-27-2017, 08:29 AM
