Hey guys my car runs good when cold but when its warmed up it has a surging problem at idle in gear and at low speed and has a miss.

I have replaced all ignition related parts coil, wires, cap, rotor, plugs, ignition module and still have the miss and surge.

So I checked the injector resistance like ive seen in other posts and these are the results.

COLD
1=16.8
3=16.5
5=16.3
7=16.8

2=16.9
4=16.2
6=16.8
8=16.3

HOT
1=17.8
3=11.7
5=5.5
7=17.7

2=7.3
4=15.7
6=3.7
8=17.2

So do what do you guys think is it time for a new set?

 

i would agree. i discovered a really cool way to flow test injectors. i want to make a video and post it on youtube.

 

my car is doing the same thing, im stumped im thinking its injectors on my tpi to. 50 bucks a pop for those suckers.

 

Thanks guys Im pretty sure the injectors are the problem so I have been looking around and this place seems to be highly recommended and for less than $200 a set I think I might just order some and see what happens.

http://fuelinjectorconnection.com/sh...ew=read&page=1

 

you can also get them from southbay who is a site sponsor here

http://www.southbayfuelinjectors.com/

with the hot resistance readings you gave, your ECM is seeing around 13 amps instead of the 6~8 it should see.

 

Sup my man. Get em here, they are cheaper
FIC in Atlanta. Ask for Jon. He will sell you new Bosch 3 takeouts for our price. 148.95.. These are used but very, very, very, very, low miles on them. I bought a set and let me tell ya, I made a good investment.
his #770 888 1662

http://www.fuelinjectorconnection.co...&productId=134

Update... The price is now $169.95 for all 8. Still tell Jon that you were refered to him rather than Southbay Injectors so that he can sell at 148.95. Good luck.

 

Please do not spend 50 bucks a piece on injectors. Take the set you had, get rid of them for a new set. If you have the Multec injectors, do not even think of having them cleaned and reusing them, they are junk.

 

im just going to buy the set online, i work at advance and after looking online i can get them cheaper at fuel injection connection. would of been 350 bucks for borg warners through my work.

 

Thanks guys ordered a set from Jon at FIC last night should be here wednesday.

I will let you guys know if that fixes it.

 

 

just have to add my ....fic does not sponsor this site...SouthBay does besides they are always posting sales for us i am sure that if you spoke to them they would do the right thing for you..they happen to be great people to work with...."just sayin"

 

Sorry guys I would have checked with southbay because the sponsors deserve our business but I didn't know about them till after I ordered from fic.

 

I did speak with SouthBay prior to making a purchase but guess what, Did you pay for my injectors? I'm pretty sure you didn't. It's my hard earned money and I can decide how I want to spend it. Besides, with all the aftermarket parts that are available out there, are you going to buy every part you need from sponsors here in this website? Im sure you've bought items outside of this website so dont be such a brown noser. Here, keep your . I dont need them.

 

You told Pontiac 400 not to use Southbay and to go to fic, so Sorry man, but who is the "brown noser" here? Did you ask southbay about meeting the price?? I really don't care what you do with your money or who you buy from. I am just saying I'm sure that most members of any forum support their sponsors because they are supporting us! You should purchase from who ever you want and others should be able to do the same. All i was saying was that i am sure that Southbay would have been more than happy to do something with the price.

 

Hey. How is suggesting another seller being a brown noser? I never said DONT buy from Southbay. READING is a power gift that humans have learned to master. Obviously you havent mastered reading. Read my post agian. Let me quote it for you, "Sup my man. Get em here, they are cheaper
FIC in Atlanta. Ask for Jon. He will sell you new Bosch 3 takeouts for our price. 148.95.. These are used but very, very, very, very, low miles on them. I bought a set and let me tell ya, I made a good investment.
his #770 888 1662."

So where did I say "DO NOT buy from SouthBay?"
Also you quoted "Did you ask southbay about meeting the price??,," Well if you want to sound good and professional , and try to sound bigger than me, then learn how to talk. "Meeting the price." You mean matching the price. Here's a double for you . stampede52 you are.

 

Pontiac400. Sorry for the rude posts that "other" member has caused. Now this thread is contaminated with dog droppings. Thanks stampede52 for getting me fired up. You are one of a kind . shall we.
Pontiac400, let us know how the injectors go for you. Remember, they dont have a groove to install the rings that help hold em inside the fuel rail. They will be suspended in between the rail and the intake manifold. Just giving you a heads up.

 

I also apologize Pontiac 400 but you know i have been following alot of forums for alot of years, but man...some members on this forum are nasty. I sure do hope that your injectors work out for you also. I didn't know that we are not allowed to voice our opinion without getting other peoples "panties all twisted".
I guess calling someone an idiot isn't being rude? Read your post, who is the one doing the name calling? Obviously i hit a nerve Iroc Z, but you got yourself fired up. This began as "friendly banter" on my part and trying to show some courtesy to our sponsors, but i see that you are getting all worked up for nothing. By the way i did read your post and this is what it says...."He will sell you new Bosch 3 takeouts for our price. 148.95.." "Update... The price is now $169.95 for all 8. Still tell Jon that you were refered to him rather than Southbay Injectors so that he can sell at 148.95. Good luck"
.
What exactly does "our price" mean anyway? Once again, he does not pay to sponsor this forum and from what i understand on any forum, in order to advertise you have to pay....just sayin
Yes lets get no hard feelings man.

 

None taken. I left out the other member who happens to know Jon personally. So that's how I got my injectors at that stated price. Dont believe me, well that number is posted. Go ahead and call Jon if you want. Besides, there is a difference in calling someone an idiot and posting a java script icon that takes place of an intended phrase. Sounds like I lit the fuse on your tampon. There I go agian with correcting your writing skills as well as reading skills. I had enough toying around with this guy who cant let go of an argument. Kick rocks, kick rocks. I got the last .

 

FWIW

I put in a set of the Bosch Design III from FIC a couple weeks ago. Took care of my issues. They knew what they were talking about and they injectors showed up when they said they would.

 

Hey guys I installed the Bosch III injectors from FIC last night and the car runs GREAT it hasn't run this good in the 8 years Ive had it. No more stumble surging or miss it idles and drives smooth as glass.

Thanks for all of your help the injectors fixed it all.

 

good news!

 

Yup Yup. That's another one completed in the "Things to Fix List."
Good to hear bro. My biggest gain is that while in 1st and in motion, I can floor the pedal and . I was never able to spin the tires while in motion.

 

Yeah it makes it way more fun to drive. The wheel spin is great it even spins shifting in to second and pulls way harder through out the whole rpm band!

 

 

Pontiac 400 -

How did you go about testing the the injectors? Are you just measuring resistance across the injector with the connector unplugged?

 

Yeah you just unplug the connector and touch one probe of the multimeter on each terminal of the injector and check the ohms.
Mine were fine cold but when the engine was warm the numbers dropped.
The resistance should be around 16ohms if there below 12ohms there bad in the middle of 16-12 they are getting weak.

Heres a video that shows how to do it
http://www.youtube.com/watch?v=_g8PdrT0MCU

Hope that helps if you need anything else just ask.

 

I don't know if it's the gas these days (which seems to screw up everything) or cars sitting (which also seems to screw up everything) but I would say fuel injectors are a "perishable" item - it seems like over time they all need replacement. (I mean much more than people assume.)

I had a set that was quite terrible, just like the OP mine were all correct when cold. Hot was another story.

 

Hey, thanks for the info. I have a dead cylinder and have good spark all the way to the end of the my wire and new plugs. Got to be either the injector or signal to the injector. It's an 86 TA with 110K and original injectors.

 

Fuel injectors are supposed to last the "lifetime" of the vehicle which is over 100,000 miles, but not all gasolines have the same level of "detergent" as the top tier fuels. The quality of gas, stop and go driving....short trips, cars sitting for long periods of time are definitely contributing factors for clogged injectors. Nothing lasts forever, with injectors that old with that many miles on them....i would consider replacing them.

www.southbayfuelinjectors.com

 

"Fuel injectors are supposed to last the "lifetime" of the vehicle" - yep, just like "sealed for life" wheel bearings and non-greasable steering components.

My guess is that if fuel injectors had a 100,000 mile replacement interval there would be a noticeable drivability difference once changed. Of course the specific design of the injector and service life which it has seen would greatly change a potential replacement interval. My girlfriend has a 3 year old Sable with funky injectors from sitting for a few months here and there. That's just horrible considering the price of new injectors. Too bad they don't stay clean for a "lifetime".

 

Ok guys,

No. 5 cyl is still dead and I did a resistance test on the injector and got 16.0 exactly. I also have 12V at the plug. I tested this by removing the connector and checking voltage at each wire. From the other posts here, I thought the computer would pulse the injector but I have 12V on both terminals. Should I be checking this with the injector connected?

Got good spark to the plug and the cylinder had 210LBS when I did a compression test.

I guess a clogged injector shouldn't be ruled out?

 

"but I have 12V on both terminals." - on both? Or on one terminal? One side will be pos and the other will be neg. However, with the injectors cycling the negative side will be more positive than ground and therefore it may "seem" to be positive. (ie: it is positive in comparison to ground temporarily)

It is possible to have a clog or internal failure of the injector that is non-electronic. What has brought you to the conclusion that the cylinder is dead?

 

If I touch either wire on the connector I get 12V. But then again I get that on the other connectors also which is why I asked if I should be testing with the connector on the injector and proping the wires.

The engine is definitely running with a miss. I pulled ignition wires off one at a time (Very carefully) while running and only no. 5 showed no rpm change when pulled off. I checked resistance of the spark plug wire and it was the same as all the others. I didn't do anything with the cap and rotor yet but that's because I had good spark at the end of the wire when grounding it.

 

swap injectors with another good cyl

 

Well, if you think the injector is bad then it won't hurt to do a quick test. With the car off unplug the connector to the 'bad' injector. Take a good 9V battery and rig up a couple of paperclips or wires so you can touch it to the injector's leads. Give it a touch with your leads and it should click - if it's working. If it clicks give it a few quick taps with the leads just to make sure it keeps working. Just don't leave the connection on for more than a fraction of a second in case the injector is good. (You don't want to damage it)

BTW, you could also use 12V battery power but it's not as convenient..

So, did it click or did it make no noise? If it clicked, try that when the engine is running. At idle you should notice a change if it wasn't firing and you are making it dump fuel in. Another thing is that if it is dead, there shouldn't be a noticeable difference in how the engine runs with the injector connected/disconnected. (Though bear in mind that you change the circuit's impedance when you disconnect an injector so you technically effect that entire bank).

And if nothing occurred you can always pull an injector off of a 3.8 or something similar and plug it in. I know from my testing that the late 80's - mid 90's 3.8's have easy injectors to get to and they are almost 16 ohms. The ones I pulled from a 1990 Bonnevile 3.8 were 19Lbs I believe - right on par for a 305TPI. Sure, it's undersized but it could be a good testing tool, it was for me. You may want to try an injector from a supercharged 3.8 though. Just don't pay more than a few bucks for one. I have some of the 19lbs 3.8 liter injectors kicking around if you need one sent to you for testing. Don't know what shipping would be though, costs are up lately.

 

Got it. Thanks for the information. I'll give that a shot tomorrow.

 

If you need a OEM injector, I'll sell you one for $10. Shipping is another charge though. I just changed out mine for the new Bosch III 22 lbs from FIC in Atlanta.

 

the multec injectors were junk when they were new.
i replaced a ton of them back then.
it was pretty common to find 2 or 3 shorted injectors on a motor by the time they had 20~30,000 miles on them.
of course at about $200.00 + per injector plus the labor, you only replaced the ones that were bad at that time.


you need to check the resistance on all the injectors.
the ECM can only handle so much current. it only takes one bad injector to drive the current the ECM sees way up.
the lower the resistance, the more current the injector will pull.
bad injectors can cause a good injector to not fire.

unless you unplug all the injectors, you'll see 12 volts on both wires in the connector with the key on engine off.


if you do need a set of injectors, i highly recommend you get them from either southbay or FIC.
there are other companies out there that sell the Bosch 3 injectors, some for less money, but you can expect problems from them.

 

Ah, wired in parallel? It also makes sense that one bad injector could be drawing power from the rest even though the one that isn't firing right now seems to be good. I will do some more testing tonight.

Thanks

 

the 87 has bosch injectors, 89 up has mulecs.. i bet 1 just quit.. its not the coil shorted. call FIC and get some bosch 3's to replace those

 

This is actually for an 86 305. I just got this car for my son. The one on my profile is actually one that I'm in the middle of building right now. When I test drove it the car ran fine. It's been sitting for about 2 or 3 weeks and he starts it every 3 days and it just started running like crap.

 

Well, before buying a set of injectors... a word of caution. My 305TPI ran like crap at times. There were a lot of issues and the multec injectors tested bad. Though changing the injectors - twice - didn't really change anything. The fact that it ran "less rough" with the Bosch III's didn't help it to run smooth at all. Luckily Bosch III's for a 305 can be found cheap, my set was $20.

It turned out that one of my biggest culprits was the throttle shaft leak. Though it only leaked when it wanted to.

If you are on a budget, try like I said - find an early 90's 3.8 motor. The fuel rail is on top and 2 or 3 - 10mm bolts are all that holds it down. The injectors come out quite quick and would be a psuedo stock replacement for a 305TPI. Just get 1 or 2, though don't pay more than a few bucks each - who knows if they work! (Bring a battery to make sure they click and an ohmmeter)

Basically what I'm saying is to watch out for money pits - when it "seems" like one thing is the problem, it could very easily be something else.

 

Glad it worked out for you, my car is doing the exact same thing (surging at idle). Have done a complete tune up, and still does it. I checked the injectors while cold and got similar number as you (havent checked when warm). Looks like injectors are in my near future.

 

I had the surging at idle (once warmed up) as well. Replacing the injectors helped it, but only to a certain extent. I think the vacuum leaking from my throttle shaft was a bigger issue. Basically the surging was the A/F ratio going crazy - unfortuantely if the computer had just left things as they were in open loop there wouldn't have been an issue. I found that adjusting the idle speed set screw (which isn't supposed to be adjusted normally) helped out, all I had to do was bring up the idle speed about 50-100 RPMs. Though it was only a band-aid approach.

I think the thing that made my car run the best was unplugging the O2 sensor. The car ran in closed loop and "thought" it was seeing stoich.

Everything is past tense as I'm in the middle of a carb swap Though I've had some issues with sellers on eBay for parts and it has delayed me...

 

just looked at south bay's injectors. on sale for $160 right now and normally 165. I think somebody read this thread and said, "screw FIC i can do one better." now i'm about to buy some injectors from them but I was just curious if gasket set that comes with this afpr would be enough to use when replacing the injectors. (my 3 and 4 injectors are trash and I can disconnect them with no impact at idle)

 

Well... I would watch out which injectors you buy. According to various sources the yellow Bosch Design III's are 19LBS/Hr.

The issue with this is that some companies are selling them as 19LBS/Hr. injectors that fit a 305TPI and some are selling them as a higher numbered injector for a 350.

When you consider that yellow Bosch injectors go to a Ford 302 or 4.6L one must question that situation..

I personally would go with the larger 24LBS/Hr. Bosch III's on a bigger motor. Though I have a stock 305 and I will tell you, it surely was NOT running rich with the yellow Bosch Design III's. (I was monitoring O2 output quite a bit along with pulse width and such. The pulse width was actually longer than I would have liked)

About the gaskets - I did mine twice in a row and pulled it apart a few other times. The throttlebody gasket and upper plenum gaskets never needed a replacement - they didn't stick on anything. Those are the only gaskets to worry about for injectors. BUT! O-rings... you are technically supposed to replace injector o-rings and fuel system o-rings every time you take them apart. You will need to take apart the fuel supply/return connections above the water pump. Those each have o-rings... (I never replace fuel system o-rings, but they always look like they NEED replacing.)

 

the yellow bosch lll's are rated 19lb at 36psi, they flow 22lb at 43.5psi. We have bosch lll's that flow 19lb for the 305 they are a cream color. We also carry 24lb, 27lb, 36lb, 42lb bosch lll's with our new adapter that will make them a direct fit for TPi setups. Using the 22lb injectors in a 305 is totally do-able but you may not obtain optimal fuel mileage.

www.southbayfuelinjectors.com

 

the keyboard mechanics are at it again. All ford injectors are rated at 39.15 psi fuel pressure. Gm runs 43.5 and in most of their 97 and up they run 58.. So do the math and stop fighting the injector guys that give us a good product at a good price. The yellow design 3 which I have in my car flows 21.85 on my New age flow bench. Its very accurate and I know my my BLM are right on the money. Now my wifes 305 has them also, her BLM is always 122+_ so its a little rich.. But, the computer pulls out fuel as needed to stay in stoich. Also injector size is based on BSFC not cubic inches. My 99 7.4 pickup has 19lb multecs right from the factory. The Bosch 3 with a fitment mod either from FIC or southbay is the best thing you can do for a TPI. The multecs are garbage and the old style bosch in 88 down are just old.

 

Ok, I got anywhere from 15.9 to 16.3 between all injectors. Applied 12V to number 5 injector and injector does click. While it was running, I applied 12V again and didn't notice any change. I think I'm just going to bite the bullet and pull the injector out. I didn't really feel like taking this thing apart but what else can I do. I can't think of anything else it could be.

 

this might sound silly but it might be stuck.. the coil is not shorted.. before you pull it out beat the side of the injector with a good size long philllips screwdriver while its running.. sometime the taping of the side of the injector frees up the suck pintle..nothing to loose