Is it possible to have 1 (or 2) injectors that are waaaaaay out'a spec but the check engine light doesn't come on (but does work)?
The car only runs poorly at random intervals (fine for 2 days, a beoch for 15 minutes, then fine again for awhile).

When I checked the injector resistance (following the fsm) I got the following resistance for each (please note however that the car ran absolutely fine immediately after this test...)

REAR
#1 - 13.2
#3 - fluctuates from 13.7 to 54 (yes....., 54...)
#5 - fluctuates from 29 or more

FRONT
#2 - 12.8
#4 - 12.8
#6 - 12.6

I've been dealing with this rough idle, stalling, hesitation (at any speed, at any engine temp) for quite awhile now and it's pissing me off.

I've already...
-swapped the plug wires
-swapped the fuel pump relay
-checked the plugs (irridium)
-checked for spark on all cylinders
-checked the engine temp sensor (actually checked 2 and couldn't get a reading??)
-checked ECU codes (55)
-unplugged O2 and drove for awhile (no affect)
-changed gas
-run methanol in gas
-run concentrated fuel injector cleaner
-replaced fuel filter
-checked cap and rotor (even with water to check for arcing)
-checked and replaced vacuum lines
-cleaned K&N airfilter
-cleaned throttle body
-cleaned IACV
-swapped power transistor (near distributor)
-swapped ignition coil
-cleaned all fuel injector harnesses and used dialectric grease on as many connectors under the hood as I could reach
-swapped MAF
-and other stuff I can't remember...

NOTE: everything I 'swapped' was from my 1990 engine - which ran fine b4 I took it out, so I trust the parts.

Any help or insight would be greatly appreciated at this point.

 

Sounds like #3 and #5 injectors may be intermittently failing...Especially #5..

 

is there any other way to spot a failing/failed injector besides just the ohms you measure through it? can an injector have an ideal resistance figure, but still be dying/dead?

 

not sure?

Why you ask?

 

not that i suspect any sort of problem with my injectors, but I was just going to check them all to see, and i was wondering if i get good resistance figures if that means i'm home free or if there could still be a non-resistance-related problem that I wouldn't know about. I'm going to do a lot of general checking this week, looking at things i've never looked at or checked yet.

 

"If it ain't broke,don't fix it"

 

Ya, that's what I'm thinking now. But I'm curious if it's even possible to have 2 injectors that are sooooo out'a spec...., but then have the car run fine immediately after the test??
I know it'll act-up again tomorrow or the day after, but it's still odd (to me at least?) that 2 injectors could be so out'a spec but the engine would still run fine?
Is that really possible?

 

well i mean my engine does have its problems. i just switched up 2.5 octane points but I still want to just make sure everything's in line. so i'm not fixing anything.. yet, unless something presents itself as being in need of repair.

 

Bad harness plugs maybe?

 

They probably seem to run fine but are just injecting less fuel.

Just replace those injectors. I have some VE injectors Ill check their resistance if your interested.

~Alex

 

I'm not going to say for certain that it couldn't be the injector harness or connectors...., but from visually seeing them and inspecting their inner connections, I highly doubt it. None were coroded or loose and all were clean and dry inside. Plus I added the dialectric grease.

On another note...., I thought I should at least inform others of something odd I found while trying to diagnose this issue.
I found that the upper intake has several small 'frost plug' things on it's underside (above the front valve cover - likely from casting the part). When you're looking at the engine (in the car), all of these 'frost plugs' are in the area between the IACV and the throttle body - right behind the vacuum lines). These frost plugs can rust, and then leak.
My symptoms caused me to suspect a vacuum leak, so I started looking and listening. Well....., inserting a peice of paper under the upper intake, inbetween it and the valve cover, produced the same sound as if I were holding the paper to the end of a vacuum cleaner. MAJOR vacuum leak!
So when I have the intake off to replace these injectors, I'll be sure to clean these upper intake 'frost plugs', and then cover them with JB weld for extra measure, before reinstalling the intake. For now I've inserted some duct tape under there and allowed the leak to suck the tape up and seal it well enough for the time being.

So if you have a mystery vacuum leak that you just can't seem to track down - look here! It's likely that I'm the only one that will ever have this...., but I thought I'd mention it just to be nice to the other org'ers.

 

Free fix for ya

 

This is completely possible, infact the same thing happened to my 94. injectors 2 and 4 were way out of spec. One read 52 ohms the other about 9. But the rest were right within spec. the car would have its days where it ran like crap and other days it was fine. Finally got the engine code which showed a 54 if i recall... injector circuit fault... something like that. Tore the engine apart the day i got the new injectors in the mail and replaced both injectors with refurbs. Its been running great for over a year and a half now. And yes I know refurb'ed injectors arent the way to go, but on such an old car I couldnt see myself spending over 100 per injector.

 

Awesome, thx for the input. Guess I'm going to replace the back 3 injectors. I'm likely going to take them from my '90. No sense spending $170 each, plus tax (Canadian) on such and old car.

I'm guessing it's not recommended to reuse the O-rings?

 

consider yourself lucky then.
I tried rebuilts once and won't do that again.
time =money
pita = money

 

yea def get new o-rings theyre so cheap to begin with... unless theyre already included with the injectors