Jfrahm

Hi all,
I've had some success with the 4 hole EV6 fuel injectors in the 928S4 and thought I'd try some in my stock 1992 968. My stockers I suppose had not been serviced and the car has over 160K on it so when I was in there checking my cam chain and ramps I thought I'd toss a set of more modern injectors in. These EV6 injectors are quieter and shoot 4 small streams of fuel which I think is better for getting even atomization in the 4V applications. Quieter helps when listening for other noises from the motor.

Specs were hard to come by and often misleading due to some ratings at 3 bar and some at 3.5, etc. but I settled on Volvo S60/XC90/etc. injectors, Bosch number 0 280 155 831 which are about 32 pound per hour at 3.8 BAR (often listed as 30 lb/hr which I believe is at 3 BAR). These injectors also have the correct groove for the retaining clip without having to futz around with that like I do with some of the 19 and 24 pounders I use for the 928.

I did a quick low-tech flow test and determined that the stockers flow about the same as these guys, at least it was not going to produce black smoke in open loop so in they went after ultrasonic cleaning, backflushing, etc.

The car runs great! I cannot really say if it runs any better, it seemed smoother at idle but the placebo effect is very strong with minor car mods so I do not put any stock in that. I have not been logging MPG so I cannot say if that will improve. I will let it idle cold at some point and see if it seems rich or lean although it seems fine. I have a wideband but I probably will not strap that on unless I feel there is a good reason. It's just a street car.
I drove it all day yesterday, probably 70 miles and it ran perfectly.

So far so good. I thought I'd post before I got too sidetracked.
-Joel.

touareg

Good info.

ryan@usaimage.com

Hey Joel...what does a set of those injectors run ? $$

Jfrahm

I should try to correct the flow data. I bought these some months ago and at the time did the best I could to match the Gen 3 EV6 injectors to the stock 968 injectors. In my earlier post the data was not correct for the pressure.

The specs at 3 Bar I believe are:
Stock 0 280 155 010 15.2 ohm 296cc/min 28lb/hr at 3 BAR
Volvo 0 280 155 831 15 ohm 297cc/min 28.3lb/hr at 3 BAR
Both are around 32 lb/hr at 3.8 BAR from what I read.

The specs of the stock injectors are not consistent on the net, which is why I did a flow test to see if they seemed similar.

Jfrahm

About 10-15 bucks apiece used, maybe less in quantity. They are pretty easy to backflush and clean, or you can send them out.

5-0 motorsport sells the 0 280 155 767 as compatible with the 968, and from what I read it is perhaps more than 10% bigger at 347 cc/min at 3 bar. I think it'd be no big deal to go 5% larger than stock at least around here where E10 fuel is pretty much everywhere and I suppose the stock injectors were sized for "real" gas. The maps can probably compensate no problem but I'd want to be close to stock size.

-Joel.

vandal968

Did this today. Bought a set of five rebuilt injectors off eBay for $36.50 delivered. Swapped out my original never-cleaned injectors (1993 968) with 159k on them. I had an issue with the new #2 injector, I pinched the upper o-ring and had a geyser when I started the car. Fortunately the kit shipped with (5) instead of (4) since it's intended for Volvo. Swapped one out, and the car started, quite rough at first since a lot of gas had dumped into the manifold when I pulled the rail apart (twice), also I think it swallowed the pintle cover from the one that I had to swap (o-ring stuck in manifold when I pulled it and pintle didn't come with it). Anyway, after about 5 minutes, the car settled down nicely, it was really rough and stumbling for the first few minutes. Once it settled-down I went for a drive. It ran great, cured a dead spot it had just off-idle. Top-end 5k+ feels a bit stronger, midrange unchanged. I'm curious to see if it starts better tomorrow morning when cold (better atomization). Lately it starts pretty quickly (about the "two" of a 2 Mississippi crank), but not instantaneous as it was 15 years ago.

Clip the individual injectors to the rail first, then plug them into the manifold. Don't worry about orientation of the injector connector until after it is clipped. Get it in at whatever orientation is most convenient to install the clip, then spin the individual injector so that the connector lines up with your harness, it will still turn easily after being clipped to the rail. Probably obvious to most, but I've never messed with injectors before.

This is a great swap, thanks Joel.

thomasmryan

If one drives at elevation, you might check if your negative fuel trim hits the limit in closed loop. Most software in the early 90s pegged out at +/- 15%

vandal968

I'd be very interested to take it through smog and see the numbers (since this car is pre-OBD 2 they run it through all the gears on a rolling dyno in AZ), but I don't want want to risk losing my existing "Pass" cert.

cheers,
c

Jfrahm

I've smogged my 968 with the 831 injectors at least once (last Summer), probably twice. No problems. Very good smog test results. This is at 5K feet /1500m
Driving at much higher altitudes has not been a problem, but then the 831 injectors are spec'd as flowing 1% more than stock, in the noise IMO. If someone has tried the 10% bigger ones it'd be interesting to hear how that goes.
15% max fuel trim sounds stingy, wouldn't you be about max'd out in Denver?

vandal968

Took the 968 this morning to drop the kids off at school. Was 48F after sitting outside all night, start time was about the same as old injectors (a hair over 1sec of cranking), but those rough spots just above idle which were most pronounced when cold are completely gone. It's just as smooth to drive immediately after start as it would normally be once warmed-up. $36.50 very well spent.

I wonder if it's worth sending my old injectors out for cleaning and seeing if I can get anything for them. Last time I checked, they sold for something like $650/ea new.

cheers,
c

Swanson11

Reviving an OLD thread here. I've got very noisy Bosch injectors in my S2. Would these EV6 fuel injectors work on my stock S2 (and be quieter)?