Bigger injectors and idle quality/speed

[BJM]

I swapped in some Blue Tops after using 30# injectors and the idle just won't act smoothly, I have swapped everything, IAC, MAF, module, coils, wires, plugs, etc. These were used injectors and although I had them cleaned I think their spray pattern is lousy.

My previous Accel 30#ers idled perfectly at 675-700 RPM, whatever I picked.

If I upgrade to something larger like 009s, 50's. I know people say they idle like stockers, but let's face it the stock idle is nothing too great. Will I have to raise my idle speed to make it smooth or do people have nice idles at slow speeds. My car is all stock internally.

009s are plenty for size for me and they are also quite cheap, can they idle nicely?

 

[Nick Micale]

The 36# blue top injectors are the best stock replacement injector available. Have installed MANY set over the years [last time was yesterday!] and never had a problem. EXCEPT, a new set I installed had one injector that was not operating at all.

You either have a bad injector, or did something during install that is affecting idle/run problem. It could also be the chip you replaced when you did the change, or did not set fuel pressure properly?

 

[BJM]

I modified my own chip and everything runs perfectly except idle. Once I adjusted tip-in, etc. everything drives perfectly, I like them while I am moving. When they were cleaned the report indicated that 3 had poor spray patterns and lower flow. After cleaning they all had the same flow and the spray pattern was judged to be good on all of them.

I have adjusted or swapped everything except the ECM itself. I should take one last look for vacuum leaks around the injectors I suppose. These are real Ford injectors so they are pretty old I assume, maybe one of them is lazy electrically.

Chip wise I have played with a lot of stuff, and I have to use an open loop idle or else the erratic idle causes it to stall, I don't think its the injector harness because I have looked at it carefully and the car runs perfectly off-idle.

 

[ijames]

From seeing them on other cars, the 009s will give a raw fuel smell from the exhaust at idle and you may have a big tip in stumble to tune out, but they do seem to idle smoothly. On my own car I've had stock, 40's (red stripes; had the same raw fuel exhaust smell so I attribute this to the disc style stream instead of a pintle style spray cone), and 72's, and they all idled the same (smooth to just slightly rough, with stock cam, heads, and idle speed tables) and gave the same gas mileage on the highway. Around town is tougher to say since as the injector size went up the foot seemed to go down .

 

[BJM]

I plan to put my Accel 30# back in to test. I discovered that the 30# have huge low end flow like the 009 is reputed to have. I had to trim the tip-in table down to 40% of stock, and play with the MAF table a lot to flatten out the BLMs. The Accels appear to be relabelled Bosch units. I was a bit unhappy to find that the Blue tops were only 10% bigger than the 30#s. This is why I was thinking of 009s but the Blue tops are disc style as well and they do seem to be causing me some grief.

 

[bruce]

Did a piece of dodo fall in, when you were swapping injectors?.

EGR sticking?.

And when all else fails when you have a fuel problem, make sure the ignition isn't the real problem.

 

[BJM]

I think I did everything possible to make sure the ignition was fine but I have run out of things to swap.

Module
coils (Type II)
plugs
wires

Nothing affected it at all.

IAC lowered to near zero helped but where it was worked fine with previous injectors.

Cool morning air makes it worse, warm air helps and that is why I notice it more now, the weather cooled off in the last month.

Cranked fuel pressure way up, lowered it way down, almost no discernible change. Low fuel pressure seemed a touch better.

Idle mixture is commanded to 13.2:1.

I am worried that since these things were cleaned that something got loosened but not removed until it was in my car.

I should check EGR.

 

[Fakeyankee]

A little off the subject but how do you get your injectors tested and cleaned ?? I have seen the article on how to clean them yourself on GNTType.org, but where would you go to have someone check them out ??

 

[Pronto]

I had Cruzin Performance do my 36lb injectors and Eric do a chip for me. Runs fantastic! Idle is very good and from the butt dyno it's making way more power than the stockers and a Thrasher 92 chip.

http://www.cruzinperformance.com/fuelinj.html

http://www.turbotweak.com/

 

[BJM]

Check your phone book for places that service diesel injection pieces, they will normally also do gas injectors.

 

[Fakeyankee]

Thanks BJM !!