Do stock replacement trilogy 650/950 injectors need tuning?

[boostd92]

I am doing all the research I can about the rough idle and part throttle/cruise issue I'm having. I've ordered a throttle body rebuild kit, all the fuel filters (tank and engine), and a bunch of new tune up parts (PCV, vacuum advance, fusible links, etc).

 

The stock injectors the previous owner gave me in a box are junk and leak, so I don't have the option of going back to stock. The car has 89,000 miles and is bone stock except a TEP radiator and the Trilogy injectors. I found the vacuum hose to the FPR was split and I replaced that, but no change in driveability.

 

I've searched and searched and searched and I keep turning up threads about people saying that the 650/950 injectors run lean at idle and idle is poor, etc until an SAFC or MAFT is used. But invariably, there is someone who chimes in and says that on a stock car, these symptoms should not be there.

 

I'd love to put stock injectors in if they were available at a reasonable price - hell, I'd like to keep the car as stock as possible, but from what I'm reading, because of these injectors, I will (possibly) need:

 

1) MAFT/SAFC

2) Fuel Pressure gauge

3) Wideband sensor/gauge

4) Adjustable fuel pressure regulator

 

Any insight from the pros? I'm waiting on my bucket-o'-parts from DAD to do the full tune up (including heli-coiling the exhaust manifold studs), so I know a real solution or diagnosis isn't truly possible until it's all running correctly, but insight on good running setups with these specific injectors would be AWESOME!

 

Thanks!

 

-Adam

[importwarrior]

i believe so. they flow more and have a different spray pattern then stock.

stock has a wide spray pattern the delphi is more narrow. my thinking is that

the delphi are meant to aim towards the valve where the stockers are meant to

be sprayed so it can puddle kind of whicked in to the cylinder.

stock is a 550 and 1050. also Delphi usually have about 43 to 45 PSI normally.

see if any junk yards have the injectors and pick them up to be tested cleaned and flowed.

[HeroJr]

If you check out scott87star's answer in my post, which is asking the same question, the news about Trilogy Turbo injectors as a totally stock replacement is not good. I think they are offered as stock replacements because they fit the fuel injector tophat and are close to the stock size in volume.

 

http://www.starquestclub.com/forum/index.php?showtopic=139862&do=findComment&comment=1387321

 

I can tell you that my test on my car was as follows - it came with Trilogy Turbo 650 / 950 injectors and ran lean at idle and part throttle. I took stock injectors off of a completely stock other (rusty) Conquest I have and the car instantly ran at the right AFRs. The previous owner installed a wideband, so I can see the results. The car on the Trilogy Turbo injectors ran 15.5 and above at idle. With stock injectors, it idled at 13.0 and did part throttle and cruise at 14.7. I even switched to some other slightly leaky primary stock injectors I had, and it still idled at 13.0-13.6 and did part throttle and cruise around at 14.7 ish. So, the car is running correctly, unless I switch back to the Trilogy Turbo injectors.

 

You COULD try to look for some Python injectors. If you go to their Web site, you can find part numbers for stock injectors for the Conquest. There are a very few Python injectors left on various Web sites out there as far as I could tell. Those injectors, I THINK, are stock Conquest injectors that were cleaned and tested by Python. I shied away from getting some because of two reasons : 1) I found various posts on different car Web sites where people complained that they had to keep sending Python injectors back because of leaking and 2) I think eventually I will have to find a "tuning" solution, such as what you describe because all of the original stock injectors will eventually be leaking.

 

Good luck!

[boostd92]

Thanks!!

 

Yea, that's my real concern... even if I find stock injectors in the junkyard, they will eventually leak. My 89,000 mile car is really low mileage and any junkyard car is likely to have more miles (and conceivable worse condition injectors).

 

I'm okay with getting a tuning solution - it will cost some money but in the long haul will be worthwhile.

 

The real problem is that I never had the car when it was running normally.... and the previous owner says he has had several starquests and that they never idle good and this is normal, but I'm certain it is not... getting to the bottom of what is "normal" might be very difficult not having stock injectors, and never having driven the car WITH good running stock injectors

[bha280]

You could send your stockers to RC Engineering and have them cleaned and tested. I sent them some junky and rusty looking injectors and they came back looking brand new and flowing exactly what they should. I think it was like $25 each including shipping both ways.

[boostd92]

^ did that. They said they were junk (leaked from the top.. not fixable).

[Starfighterpilot]

You could send your stockers to RC Engineering and have them cleaned and tested. I sent them some junky and rusty looking injectors and they came back looking brand new and flowing exactly what they should. I think it was like $25 each including shipping both ways.

 

I agree. ^ I'd send the 89K mile injectors in to have them cleaned and tested before I'd spend the money to buy the new after market parts that you noted in your OP. 89K is mid-life for the OEM injectors. I had about 180K on the last Starquest set (however I cleaned 'em using Lucas Upper Cylinder Lub with injector cleaner every 5 - 7K miles) that I recently replaced. I'd clean the male terminals and then do an ohm test on 'em. If the ohms are around 3 then I'd send 'em in. If it's more that 3.3 ohms then they are shot. Also inspect the injector clips for a snug fit in the injectors and clean the metal clip terminals with a jewelers file and electrical parts rattle can cleaner.

 

Yeah, I know that the FSM says the max ohms are 3. But, I have successfully used clean Mitsu Starquest injectors when they have read 3.2 to 3.3 ohms for many, many K of miles.

 

In addition to the parts that you said that you're gonna replace, I'd also replace the plug wires, dizzy cap & rotor and replace the plugs with NGK 7031 ones.

 

Check ohms of each of your new plug wires to ensure that they are less than the maximum ohms noted in FSM Chapter 8. Over the years, I've run into a couple of brand new sets of plug wires that had 1 or 2 wires that were over the max ohms. Took 'em back and got another set that tested good. Never had a problem with the NGK wires - but I still test the new sets that I buy.

 

Set your new spark plugs' gap to about 0.039" and then do some WOT pulls when the engine is heated up to Normal Operating Temperature. No spark blow out? Good! then increase the gap another 0.001" and do the WOT pull again. Keep on doing the incremental gap increase until you get spark blow out then drop the gap back 0.001" to when you didn't get spark bow out. Incrementally decrease the gap by 0.001, after each WOT pull, if you get spark blow out at 0.039", to were there's no spark blow out. You are tuning your engine to get the maximum spark that you can so you burn as much of the air/fuel mixture that is possible in YOUR PARTICULAR ENGINE. If you ever saw dyno engine testing experiments you would be amazed at how much spark plug gap effects engine performance.

 

One very possible reason that you have poor idle is that the EGR is plugged up or it's diaphram is shot. I would pull the EGR valve out, test it & it's vacuum tubing and clean it and it's intake manifold cavity when your rebuilding the TB. See this link http://starquest.i-x...er=asc&start=25

 

Check ALL of your vacuum tubing for hardness, cracking or holes - and that it's hooked up to the proper component location.

 

Depending upon you car experience, I'd also disassemble, clean and regrease your dizzy. The grease in it is 20 something years old and it very possibly may be affecting the correct operation of spark advance and retard. See this link for how to do it http://starquest.i-x...opic.php?t=1131

 

If after you do the above and you still have problems, THEN I would consider installing the new parts (1 through 4) described in your OP.

 

By the way, if you are going to helicoil the exhaust manifold stud holes make sure that you use helicoils made especially for aluminum. Standard, off the shelf helicoils are for cast iron or steel.

 

Don't forget to clean the electrical terminals and wire connectors on your coil.

 

I'd also check out this link http://www.starquest...showtopic=66449

 

For What It's Worth.

 

KEN

 

Had another brain fart - check your Lady's error codes IAW the FAQ which tells you how to do it. If the O₂ analyzer is shot; ISC is frozen &/or it's nose switch contacts are corroded; or the MPS is inoperative (which are the usual culprits) each of which could also be another reason for your problems.

 

Let us know what you find.

[boostd92]

I will do all of the above! Thanks!

 

Again, the stock injectors were shot (verified by Trilogy Turbos who tested them) so that's not an option. The exhaust leak is really bad and since it's pre-turbo, I'm afraid that the air getting in there may be skewing the O2 readings at idle. I really can't do any "fixing" until that portion is fixed. The stock cat/dp looks like a big rusty brick. We don't have emissions testing for pre 1995 cars here so i can go nuts with it. I ordered a catless dp from TEP with an extra wideband O2 bung wedled in.

 

Any tips on eliminating the secondary air and EGR? I'm sure I'll need some block off plates for one or both - are they available in the aftermarket? I'm not concerned about secondary air, as there will be no cat to heat up. I understand the environmental impact on removing the above, please no lectures if it can be helped - I'll be operating within the stated laws in my county

[boostd92]

I checked out those links above, seems like they would be very helpful if the pictures were still online

[importwarrior]

Secondary air mod is 2 quarters. Search for it.

Egr. EBay 101propose AKA mookeeh has a block off plate

 

I just cut a coke can up. Made the can tin flat. Folded it in half

And cut to size. Only made holes for the bolts to go throuugh.

Bolted egr back on. Used tin like a gasket.

 

Egr does not rob you of too much if any power.

Edited November 1, 2013 by importwarrior

[boostd92]

^ Ha! Thanks, I remember doing the coke can mod on my 1ga DSM.

[boostd92]

"secondary air mod is two quarters"

 

I see reference to the two quarters in the downpipe... I'm going with a TEP downpipe, so no need there. Is there a hole left in the intake manifold when removing the metal air box? Is that two quarters too?

[Malykaii]

You can get flat aluminum sheets at home depot... got something like 2ft tall and an inch wide and 1/8? thick for like 5$. Cut an inch off, drilled two holes and found some shorter bolts. I wish I knew about the coke can trick... would have used that as a gasket instead of the old original one.

[Starfighterpilot]

"secondary air mod is two quarters"

 

I see reference to the two quarters in the downpipe... I'm going with a TEP downpipe, so no need there. Is there a hole left in the intake manifold when removing the metal air box? Is that two quarters too?

 

 

No Hole in the intake manifold when removing the secondary air cleaner. You just have to block off the vacuum line that went to it's actuator diaphram.

 

I find that it is ironic that in your OP you were complaining about the Delphi Fuel injectors contributing to uneven idle etc. and yet you are going to eliminate the EGR valve that helps warm up the intake manifold faster during cold engine start up which causes better atomization of the fuel in the intake manifold runners giving a MUCH smoother idle.

 

As importwarrior stated the EGR valve does not hardly cost any power loss, if it was me, I'd reinstall it after I made sure that it's internals are clean and working correctly. It will sure help your lady run better during cold start up on a COLD Chicago morning.

 

To see the pictures on i-x.net's SOS Manuals you have to become a member of the site and log in - then the Manual's Topic's pictures, at least 90% of 'em, magically appear.

 

For What It's Worth.

 

KEN

[boostd92]

I'll keep the EGR parts just in case. I respect your opinion and if these cars really can't cold start well without an EGR installed... well... that doesn't say much for the design. But I believe you. We will start with cleaning and inspecting everything and once the idle is stable, then remove the EGR.

 

I'm on the fence whether to buy a member's used GM MAF and MAFT for cheap, or by the MAFT gen2. If I buy the MAFT gen2, I should be able to get away with just buying a WBO2 sensor (no gauge needed, as the MAFT gen2 reads the input)... that will save me the difference in a gen1 MAFT and gauge.. plus better datalogging capabilities. Thoughts?

[StarquestRescue]

I should be able to get away with just buying a WBO2 sensor (no gauge needed, as the MAFT gen2 reads the input)... that will save me the difference in a gen1 MAFT and gauge.. plus better datalogging capabilities. Thoughts?

With the gen 2, you will still need the wb controller. And might as well get the gauge also. The data logging capability and added tuning features will be a big plus. If you are not tech savie, you may have trouble getting the data logging and laptop interface to work.................................These cars are a little cold blooded though, do not expect late model cold start drivability. Edited November 1, 2013 by StarquestRescue

[marso]

You will never run the correct steady AF mixtures with any injector other than stock. They are not made for manifold dispersion only direct injection. The mist angle is wrong and the fuel is not atomized as much as the stock injectors. A wide band O2 will tell you just how bad the fluctuations are and it can't be adjusted stable with a MAFT. I did many posts about this but as usual there are the people who don't believe anything and have to find out the hard way. Do your best to find a good set of stockers. They are there but someone has to let them go. P.S. I just read the post above mine and he is wrong on the "cold blooded" statement. I've had five of these and all of them ran fine right after start and O2 heat up not engine temp BUT they have a normal small rough idle due to the crappy manifold and throttlebody set up. It's the injectors that make them run rough. Most primaries leak. Get a three or four wire O2 sensor so the sensor will heat up after about a minute. Edited November 2, 2013 by marso

[boostd92]

^^ So you're saying that no one has gotten Trilogy injectors to idle stable? That it's not possible? I'd much prefer stock injectors, but I'm not sure I can find them in good condition.

[jjohnson]

Wow , I just had to get a set of these so to get them to work right I need to piece together a maft T gen2 system what ever that is and where to get all of that then buy a laptop to make it all work together lol then take a couple college computer programming courses geese

[jjohnson]

All I wanted to do is get an accurate way to read air fuel so I can adjust my fuel pressure.

[StarquestRescue]

All I wanted to do is get an accurate way to read air fuel so I can adjust my fuel pressure.

Any wide band gauge will do that. The aem one is good. Raising the fuel pressure works for most people. Most do not get in to the maft till later when they want to up the boost. At that point the base model works good for most people. No computer stuff need. http://www.fullthrottlespeed.com/itemdesc.asp+ic+050DSMTRANS1G+eq++Tp+

[StarquestRescue]

^^ So you're saying that no one has gotten Trilogy injectors to idle stable? That it's not possible? I'd much prefer stock injectors, but I'm not sure I can find them in good condition.

If you can get the idle afr to 13-13.5 it should idle pretty good.

[boostd92]

Gotcha. I'm going to try to make the most of what I've got.. (trilogy injectors) if raising the fuel pressure makes a better atomized spray pattern, I will do that.