1uzfe injector seals

[alunwill]

I serviced my injectors a few months ago, replacing all the seals and o rings, together with checking spray patterns but I've had an annoying rough running when I put my foot down. It passed the emissions test with no issues, it always starts first time and sounds fine when idling.

I traced it to #1 and #7 cylinders. Electrics were fine, maf etc was fine just this annoying miss when I put my foot down.

I pulled the passenger fuel rail out yesterday and fitted genuine toyota top and bottom seals, plus a little bit of vaseline just to let them slide in to the heads a bit easier!

When I initially serviced the injectors I'd noticed the bottom seals were full of hairline cracks so they definitely needed changing.

The seals kit I originally used was from bhp. They supplied solid donut style seals which at the time I thought was unusual. The correct oem seals were a crazy price from toyota and 4 weeks leadtime.

A few weeks ago I finally ordered oem parts from Rockauto. These seals are more open, are shouldered and have more "give". Basically the toyota compresses down into the seat whereas the bhp tries to bridge the seat. When I checked there was also a height difference meaning the rail didn't sit naturally.

So, the moral of the story, use genuine parts even if you have to wait a few weeks for them to arrive.

End result is the vacuum problem has gone and no miss when I get above 2000 rpm.

[Gatwick Axe Man]

Hi Alun,

wouldn't happen to be these ones https://www.ebay.co.uk/itm/Lexus-1UZ...AAAOSw-PFahV5p ?

Haven't run my engine yet but they did look "different" to the originals, fitted but as said not run yet. BHP have been pretty good with getting parts that I couldn't find anywhere else so far and next day delivery on most stuff.

Do you have the Rockauto part number to hand? Might have to have a look and see if there are any deals to be had at the moment.

Graham.

[alunwill]

Hi Graham,

Yes those are the ones.

The toyota part numbers, which rockauto uses are below

top- 23250B (O ring to fuel rail)
Middle - 23250C (vibration ring, I think that's what they call it)
Bottom 23291 (actual cylinder inlet port seal)
Micro filter 6 x 12mm for EV1/EV6/EV12 type injectors

Last time I checked injector planet in the states also had them in stock.

Not tried toyota uk for a while.

[Ian C]

Alun,

I had a similar experience with leaking injector seals but came to a different conclusion. My problem took the form of variations in the AFR between banks which was traced to leaking injector seals (the bottom seal aka cylinder inlet port seal) on a couple of cylinders.

Like you I had replaced the original Toyota oem seals when I refurbished the injectors and performed a flow test. The seals I fitted were purchased on eBay and looked identical to the oem seals that (I assumed) were the originals (the top row of seals in attached pictures). They came from an outfit called Tokyo Auto Salon and the price, of £18.50, should have been a warning!. When I had the problems, and eventually traced it to poor sealing allowing air to be drawn in passed the seal, I purchased new seals from the BHP on-line shop. I had further problems when these seals were fitted but this was entirely down to my cack handedness and trying to do the job quickly instead of properly. I tried to avoid having to removing the rail completely and attempted to fit the seals while wedging the rail and injectors out of the way.

Once I had bitten the bullet and removed the fuel rail to give access, fitted the seals and then refitted the fuel rail & injectors - taking great care that the seal was central in the inlet port and that the fuel rail was sitting properly on the spacers and bolted down securely - I had no further problems. My assumption was that the problems I had experienced were due to substandard seals and I have had no issues with the seals from BHP even though, as you rightly say, they are a different profile from the Toyota seals


Hope this helps.

Take care,
Ian

[alunwill]

Hi Ian,

I understand your point but for me the donuts are too rigid and a bit much like "hit or miss" with regards to aligning the seals. The benefit for me of the toyota seal is that it's shaped and designed to compress down to allow the injector to positively locate and seal into the port whilst also sealing into the seat. The donut doesn't allow this.

[TonyD]

I too have been having fun with injectors and have also gone down the Rockauto seal kit route.

Now a question. What is the best mthod of cleaning the inside workings of a sticky injector?

I have spare fuel pump(s) , a spare fuel rail and a spare injector harness. So I am very tempted to rig up a bit of a Heath Robinson injector test, volume of injection measure and cleaning rig. Turboshed on You tube did something very similar but it looked a bit too professional for me. There was hardly any opportunity for fire or other drama.

I'm thinking that just clean petrol may not be sufficient to give the cleaning action required but I do have access to paint thinners/ gun wash by the gallon and also large quantities of pure industrial alcohol.

What would be the best cleaning solution out of those two. I have focussed on both these chemicals because they are free.

Cheers,

Tony

[alunwill]

Hi tony,

How's things going.

I used a can of carb cleaner(aerosol), rigged a tube to feed into the injector and bought a box of tricks of ebay for £20 that allows you to cycle the injector. It does the job but a rail would be better.

[TonyD]

Hi tony,

How's things going.

I used a can of carb cleaner(aerosol), rigged a tube to feed into the injector and bought a box of tricks of ebay for £20 that allows you to cycle the injector. It does the job but a rail would be better.

Hi Alun,

Things are going well thanks to your jedi soldering skills.

I reckon carb cleaner is just a solvent like thinners or acetone but I will get down my local motor factors and take a look at the contents listed on the can. I did quite a bit of research some years ago on fuel additives for the purpose of cleaning both petrol and diesel injection systems and it was amazing how many of the safety data sheets for the products I examined detailed contents such as, in effect, cheap thinners or gunwash in a kerosene base.

Cheers,

Tony

[Ian C]

I understand your point but for me the donuts are too rigid and a bit much like "hit or miss" with regards to aligning the seals. The benefit for me of the toyota seal is that it's shaped and designed to compress down to allow the injector to positively locate and seal into the port whilst also sealing into the seat. The donut doesn't allow this.

Alun,

I totally agree re the profile and positive location of the Toyota seals. I think my problems stemmed from buying cheap seals from an unknown eBay site. They were badly deformed and already showing signs of deterioration after only a few hours running. The donut seals definitely seemed to be a better quality and have (so far) done the job, time will tell. If I need to replace them I will certainly be looking to travel the Rockauto route

. . . .Now a question. What is the best mthod of cleaning the inside workings of a sticky injector?

I have spare fuel pump(s) , a spare fuel rail and a spare injector harness. So I am very tempted to rig up a bit of a Heath Robinson injector test, volume of injection measure and cleaning rig. Turboshed on You tube did something very similar but it looked a bit too professional for me. There was hardly any opportunity for fire or other drama. . . .

Tony,

When I checked & refurbished the injectors I used contact cleaner (because I had some) while energizing the injector coil with short duration pulses (making & breaking the circuit by hand). Not sure how effective, if at all, this was but when I did the flow test (also inspired by watching Turboshed's efforts) to try and track down the lambda problem the injectors all seemed to work well.

I have attached the results of the flow test I did in case it is of any use. I took the fuel rail physically off the inlet manifold bu left it connected to the fuel flow & return lines. The Link ECU software allows the injector in #1 position to be tested using variable pulse counts, frequency and duration so I had to blank off the remaining seven ports and fit each injector into #1 position to test. I was surprised, initially, by the flow rate with the short duration pulses but realised this is a function of the finite time taken for the coil to open the injector

Hope this may be of some use.

Take care,
Ian

[alunwill]

Hi Ian,

Good data, worth sharing

Alun