Are injector pintle caps needed?

[BigVinnie]

I recieved a set of 4 Q45 370cc injectors without the pintle caps. Do I absolutely have to use these caps? If so I'm assuming that I could get them from courtesy nissan???

[SochBAT]

yep. You need em.

Without it, it is unregulated and will spray too much fuel in.

[TheRealNighthog]

They hold the lower o rings in.

[BigVinnie]

O.K so is courtesy nissan the onlyplace I will probably get these caps from? it seems almost impossible to find them.

[UNISA JECS]

Originally Posted by Soooshi

yep. You need em.

Without it, it is unregulated and will spray too much fuel in.

Yes you need them but not for that reason.

Originally Posted by TheRealNighthog

They hold the lower o rings in.

You need them for this reason.

[UNISA JECS]

Originally Posted by BigVinnie

O.K so is courtesy nissan the onlyplace I will probably get these caps from? it seems almost impossible to find them.

I dont even think you can get them from there, best bet is to call up a place that cleans injectors and ask them if you can buy some.

[BigVinnie]

Originally Posted by UNISA JECS

I dont even think you can get them from there, best bet is to call up a place that cleans injectors and ask them if you can buy some.

Rc engineering will clean injectors, and from what I have been told is that I need to get them from the manufacturer.

Can I use the sr20det injector caps on the q45 injectors? I've been told that there are variances but I don't see why it matters since the inlet boss diameters are the same, (or so I've been told).

I have a local E85 gas station down the street from my house and I wanted to put these 370cc injectors in, I burned up my stock 270cc injectors from a high duty cycle so I'm going to try something a little different with my NA/KA setup.

Originally Posted by TheRealNighthog

They hold the lower o rings in.

I am confused by this answer just because the lower ring is mounted higher on the injector than where the pintle cap is located.

Location of pintle cap..


Location of the O ring.

[UNISA JECS]

What are you putting those into? Because those wont fit a KA24DE/SR20DE(T) rail.

[TheRealNighthog]

Those look like subaru injectors.....

[UNISA JECS]

Those look like early style Q45/300ZX injectors that had problems with there coils burning out.

[BigVinnie]

Originally Posted by TheRealNighthog

Those look like subaru injectors.....

Originally Posted by UNISA JECS

Those look like early style Q45/300ZX injectors that had problems with there coils burning out.

They are VH45de side feed fuel injectors from 1990-1996. I've read up that KA-t guys can use these injectors as well as the 370cc 1995-1996 Z32 turbo fuel injectors, I believe these injectors both have the same part number.

[UNISA JECS]

http://zilvia.net/f/tech-talk/155928...fferences.html

[Homer_Simpson]

You're looking for these?

If yes, then this guy is selling them. I've just bought a few for myself from him.
--> Ebay link eBay Motors: Nissan Jecs Fuel Injector Pintle Cap (item 360106569914 end time Feb-09-09 14:20:35 PST)

[240=180]

does it matter if the little fingers on the pintle caps of my sr injectors are broken?

[SochBAT]

Hmm. I've always thought they help regulate the feed.

I remember a while back having mine break on me and it was flooding the engine.

[TheRealNighthog]

No that would have been bad or damaged O rings.

[BigVinnie]

Originally Posted by UNISA JECS

http://zilvia.net/f/tech-talk/155928...fferences.html

Sweet.. I'll take these back and get 94 and up model year Q45's.

[windshieldwiper]

you dont need them for the ka24de. lots of people bust them.

[DeatschWerks]

Originally Posted by BigVinnie

Can I use the sr20det injector caps on the q45 injectors? I've been told that there are variances but I don't see why it matters since the inlet boss diameters are the same, (or so I've been told).

I am confused by this answer just because the lower ring is mounted higher on the injector than where the pintle cap is located.

Location of pintle cap..


Location of the O ring.

I think everyone here was thinking you had the same type of injectors that KA24de and SR20s use (a 'phase2' injector.) The Phase2 injectors need the cap to keep the o-ring on. The o-ring can stay on without the cap but it's not too safe.

But that's not what kind of injector you have. You have a Phase1 style injector.
On those injectors you have, you'll notice a very small rod sticking out of the injector. That is the actual pintle. The cap for these injectors are there to protect that. It is very important to not damage the pintle on these.

Here's a quick picture I snapped of a Phase1 without a cap so you can see the pintle.


And just for reference, this is a Phase1 with a pintle cap.


Also, the Phase1 injectors will not fit in a KA24de or SR20DET fuel rail.

Originally Posted by UNISA JECS

Those look like early style Q45/300ZX injectors that had problems with there coils burning out.

Correct, those are 'phase1' sidefeed injectors. Nissan and Subaru have stopped using these due to their high failure rate.

Originally Posted by 240=180

does it matter if the little fingers on the pintle caps of my sr injectors are broken?

Your injectors will still work fine. The fingers are mainly there to protect the nozzle if the injectors get dropped.

[UNISA JECS]

Originally Posted by windshieldwiper

you dont need them for the ka24de. lots of people bust them.

Those people are on borrowed time to, there's 43psi acting upon those o-rings, if they happen to squeeze threw the bore on the fuel rail after a nice WOT pull when teh cylinder is all nice and hot, that cant be good.

The cylinder will hydrolock almost instantly, thats a major leak.

[BigVinnie]

Originally Posted by UNISA JECS

Those people are on borrowed time to, there's 43psi acting upon those o-rings, if they happen to squeeze threw the bore on the fuel rail after a nice WOT pull when teh cylinder is all nice and hot, that cant be good.

The cylinder will hydrolock almost instantly, thats a major leak.

I'm actually going to turn up the PSI to about 45 PSI to start with tuning, since the injector pulse width and duty cycle is much lower on a Naturally aspirated engine with lower HP goals, then a turbo charged sr. I believe a standard sr20dets base fuel pressure is around 46PSI?

I need a nice and clean spray pattern so uping the injector size I will need to up the fuel pressure. I've never worked with E85 so that 45 PSI @ fuel rail may not even work with E85, I am wondering if I should up the fuel pressure to maybe 48PSI.

I used the RC engineering calculator and it seems that I would need about 48PSI @ 75% of injector duty cycle to make relatively 220 HP at the crank , or roughly 190WHP. This would mean that brake specific fuel consumption is at 50%. This would be a total of 34.91 LB.s/HR @ 367cc.

I'm just going to order brand new q45 94+ injectors, any one want these phase 1 Q45 injectors for free?

[UNISA JECS]

99.9% of Nissans run 43psi base fuel pressure (no vacuum attached), this also what 99% of nissan side feed injectors are rated @.

I personally run my Q45 370cc @ 52psi base fuel pressure, this is what happends when you run a Q45 or Z32 TT fuel pump with the stock fpr and yoru getting full battery voltage at the pump.

[BigVinnie]

Originally Posted by UNISA JECS

99.9% of Nissans run 43psi base fuel pressure (no vacuum attached), this also what 99% of nissan side feed injectors are rated @.

I'm assuming that you mean that it is 43.5 PSIG static for most nissan naturally aspirated 4 cylinder pumps. Or that with no vacuum applied all nissn fuel systems require that 43.5 PSI base pressure.

Originally Posted by UNISA JECS

I personally run my Q45 370cc @ 52psi base fuel pressure, this is what happends when you run a Q45 or Z32 TT fuel pump with the stock fpr and yoru getting full battery voltage at the pump.

I was going to get a 300z TT (Z32) fuel pump since its an easier intank modification and I can get it at the junk yard.
Would I need a rising rate FPR? Or is the stock KA FPR reliable with this setup? Or do yo mean that I would use the 300z TT stock FPR?

[UNISA JECS]

The hell with rising rate POS....No there is no need for a Z32 FPR its teh same thing as the S13/S14 one internally. If you wondering why then does the static fuel pressure bump up, thats easy to explain, the Z32 and Q45 have a fuel pressure control module that limits the amount of voltage the pump sees at idle and low cruise condition, since voltage directly impacts the output of the fuel pump, teh fuel pump in the Z32 and Q45 does not overrun the stock FPR and is able to maintain a static fuel pressure of 43psi.

[BigVinnie]

I see so then all I need to get rid of is the pump voltage regulator (control module), and just run the volts directly from the battery. seems like an easy modification.

[UNISA JECS]

Originally Posted by BigVinnie

I see so then all I need to get rid of is the pump voltage regulator (control module), and just run the volts directly from the battery. seems like an easy modification.

Your misunderstanding me, unless you drive a Q45.

The S13/S14 doesn;t have fuel pressure control computer so when you install Q45/Z32 TT or big WALBRO pumps in a S-chassis, those fuel pump overrun the stock FPR and you wind up with a considerably higher base fuel pressure usually to the tune of about 7-9psi increase above 43psi which is alot.

[imwitu]

Originally Posted by SochBAT

Hmm. I've always thought they help regulate the feed.

I remember a while back having mine break on me and it was flooding the engine.

Your thought was right, at least on my 97 BMW 528i car won't stay idling if pintle caps are broken. I install the missing pintle caps and it is back to normal.

[ultimateirving]

Originally Posted by imwitu

Your thought was right, at least on my 97 BMW 528i car won't stay idling if pintle caps are broken. I install the missing pintle caps and it is back to normal.

Way to go, why do people revive old ass threads. This was from 2009. Not a current issue or topic but thanks for your input

[95RedM]

Originally Posted by ultimateirving

Way to go, why do people revive old ass threads. This was from 2009. Not a current issue or topic but thanks for your input

Today, January 12, 2023 this was a current issue and topic. Thanks for the information in this thread guys. It was useful and helpful to me with a customers car