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Na fuel injector upgrade

240sleeper

Active member
Joined
Apr 7, 2005
Location
detroit, mi
I have a 93 Volvo 940 na. I'm looking to put in some newer fuel injectors. I believe at least one of mine is leaking or has a bad spray pattern. I'd rather just pull some off of a car at the junkyard if I can. What injector off of a newer Volvo or other vehicle would be comprable to an NA injector?
 
But, a better spray pattern (i.e. better atomization) would increase idle performance and overall performance without needing to increase flow rate. I've considered getting some newer tech, nearly equal flow-rate injectors(that are still high res) to see if I can't get a better idle and overall performance. Someone try and explain that is wrong. If you can pick up some injectors that are high resistance and flow the same, why not? But of course, what is your reasoning to lead you to believe it's an injector problem. It could be an engine coolant temp sensor or a fuel pressure regulator. :cheers:
 
Or it has injectors that are too big and the fueling error decreases as the motor comes out of warm up. BTDT

Warm up has fixed parameters open loop and it will dramatically overfuel if larger than spec'd injectors are installed.

If you have leaky injectors it's likely your oil is contaminated.
 
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But, a better spray pattern (i.e. better atomization) would increase idle performance and overall performance without needing to increase flow rate. I've considered getting some newer tech, nearly equal flow-rate injectors(that are still high res) to see if I can't get a better idle and overall performance. Someone try and explain that is wrong. If you can pick up some injectors that are high resistance and flow the same, why not? But of course, what is your reasoning to lead you to believe it's an injector problem. It could be an engine coolant temp sensor or a fuel pressure regulator. :cheers:

No it wouldnt. If volvo made a redblock today, they would spec the same spray pattern and cone angle.
 
But, a better spray pattern (i.e. better atomization) would increase idle performance and overall performance without needing to increase flow rate. I've considered getting some newer tech, nearly equal flow-rate injectors(that are still high res) to see if I can't get a better idle and overall performance. Someone try and explain that is wrong. If you can pick up some injectors that are high resistance and flow the same, why not? But of course, what is your reasoning to lead you to believe it's an injector problem. It could be an engine coolant temp sensor or a fuel pressure regulator. :cheers:

I'm running stock fuel injectors from a 2014 1.8L Chevy Sonic. Drop right in, 4 hole and my car runs great.
 
When I was getting ready to add a turbo/larger amm & tb I wanted larger newer injectors too. Not knowing anything about injectors, but having LH2.4 I just bought some that should be future proof in terms of size (siemens deka 60lb) - I didn't want to have to buy another set again. They gave me the performance I wanted but a wandering idle with wandering AFR too. Didnt bother me but failed it the annual emmissions test which did.
However, the point of these ramblings was brought home in this thread http://forums.turbobricks.com/showthread.php?t=326991&page=2 which introduces the concept of "port soak". If you read the thread & watch the video on page 3 it explains it better than I can. Basically, the spray pattern etc is very important.
Incidently, I "cured" my problem by putting the injectors in a Kjet head so they fire onto the back of the valve rather than in the intake.
Tim
 
None.

After reading some of the info here and other threads about atomisation etc, I'm going to switch back to my stock n/a injectors that I had freshened up to compare. Curious to see if I really gained an improvement with the 4 hole and injector better atomisation.
 
Swapped back to my stock "rebuilt" (new o rings and pintle caps) injectors and the idle is so much better. About to drive 2 hours back to Little Rock so I'll have a better idea of fuel mileage. My mileage dropped quite a bit when I switched to the Sonic injectors. I chalked it up to the A cam I installed at the same time as the injectors.
 
It was probably not a good match with the sonic injectors. I have put a B cam in a 1990 245 wagon and my wagon runs a V15 cam and both get good mileage. That is on stock injectors. Not great mileage because we have gas that is ten percent alcohol with no one really making sure it is that much in the mix. lol.

If I recall correctly a mild upgrade that vvpete used was 16v injectors. These were setup to make 153hp so they should be a good match on a warmed up B230F 8 valve.
 
I ran yellow 850 injectors in an 88/244 with M47. The idle significantly improved, throttle tip in noticeably improved (I assume improved low end torque) the mileage increased by a little over 1mpg on the highway and about 2mpg in around town driving. I rebuilt the old injectors (cleaned, new pintle caps and rubber) and reinstalled them to see if the gains had something to do with how old and nasty my originals were and they were not as productive as the 850's but were better than pre-rebuild. I left them in and installed the 850's in another 240. That owner noticed slight all round improvement in driveability too (it was a 93/24) with automatic). FWIW, I was rebuilding injectors on a 1997 Mercury Grand Marquis(4.6L V8) and those injectors look like Volov 240 injectors except they have 4 holes. I'm going to grab some from a jy and install to see how they run.
 
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