Hank426

Ok Thanks for the info

Hank426

Ok so I got the car back together with the new injectors and fpr. Only had time to run it a little but I noticed the idle was choppy and sounded like it had a miss. What else could be wrong with it? The car definitely had a bad injector before (5 of them were about 12 ohms and the 6th was only 3.9 ohms). Nothing looked bad with the old fuel pressure regulator but I put in a new ac delco one anyway. Now what should I try? Thanks

scury13

Hmm, same boat as me. Starting to wonder if the Bosh injectors are my problem. Today I found that I can pull the vac line from FPR and plug the vac line the idle will be good. Not sure what that means. Also tried plugging the IAC passage and when I did the car died instantly. Someone said this would indicate no major vacuum leaks. Tried carb cleaner previously and found no sign of vac leak as well.

Hank426

So I got to test the car some more today. Started kind of hard and had a choppy idle. I drove the car around for a while and it seemed to clear up and the idle was fine.

I stopped the car and opened the hood to check for fuel leaks while it was running and noticed that every once in a while the idle would drop down a few hundred rpm's and idle like crap. After about 20 seconds of that it would come back up where it should be and idled fine. It did this every few minutes.

I took another short trip, came back left it running a few minutes and it would start doing the same thing again. What gives?!?!
Is there anything I should be checking or testing that would cause this? Should I do an "idle learn" ?

Thanks

scury13

The relearn would be worth a try. I have been told by a few to do it but it made no difference for me. Mine does pretty much the same thing except with some stalling when the idle is bouncing. I never had this idle issue until I changed my injectors. Either they are bad or I have a bad ECM of FPR. Really not getting any new info or thoughts from anyone. Of course were all just spit balling anyway so I will continue trying other things and report back.

Hank426

Just tried the "relearn" made no difference. New injectors really didn't seem to change much for me unless its a bunch of issues with the car. I'm open to any ideas at this point.

scury13

Thought I might have solved my issue but no dice. Rebuilt the dizzy and did idle relearn again. Better, no stalling but idle prob and erratic rpm while slowing down still there. Took a little vid clip of what it does while driving. Always seems to happen, hunting idle, when speedo drops down to 20 mph and continues until less than 10 MPH. If i don't go over 10 mph and slow sown no problem. once in park the idle varies a few hundred RPM.
Its not just a false visual from the RPM, I know its not an accurate read as it has the all to common tach issue, but you can hear the engine doing it as well. I also noticed that right at 40 MPH you can hear and fell it kind of doing the same thing. slight up down in RPM and engine sound. I read that the IAC should go closed at 40 MPH. Maybe mine is getting caught in limbo? its the third IAC, so maybe its the ECM is not doing what it should? Any thoughts?

91rs-t-tops

My problem happened to be my idle air Valve. After I broke the bolts off getting it out I cleaned where it seats down and pushed the plunger back so from the housing to the tip was like a 1 1/8 inch and used some zip ties and safety wire to hold it on. It runs perfect now. Once and a while it will stall but not often

scury13

Did your idle do the same as what I am describing? I did not try to adjust the plunger but I did not think you had too. I thought the ECM would control how far it moves in and out.

91rs-t-tops

It dose but it says to to keep from damaging it It would idle rough and die.

scury13

Ok, I will pull out and check it.

scury13

Well, IAC plunger length is right, car still has a bit of a erratic change in RPM when slowing down below 20 MPH. No more stalling and pretty steady RPM at idle than before dizzy rebuild. So, I either give up and live with it or take it to a shop who will unlikely be able to find the issue from what I have read from others. ????

91rs-t-tops

Just for grins unplug your lock out converter. I know it's probably not the problem but I had a cavalier that would do that jump fom 1500 to 2000 I unplugged it and problems stopped. It also would stall itself out because it was going out. On a dodge it's sometimes a voltage problem. It's a long shot but it could be trying to engage and disengage

thatoneguy5x

did anyone ever find a solution to this problem?? I have the same issues with my car. its really starting to upset me. almost made me crash a couple times when it stalls and my steering and brakes go out.

so far ive noticed that when slowing down it will bog up and down after its reached operating temp. runs fine any other time.

also when its at temp and I have it in park or any other gear and pump the brakes (not moving) it will do the same thing, bogs down almost to the point of stalling.

if I disconnect the IAC the problem goes away. but ive tried 2 other IAC valves and the problem persists.

ive replaces all vacuum lines, my fuel pressure is good and holds for the required time, CTS is about a year old, fuel filter is about a year old, plugs are new, wires are a year old, dist cap and rotor are a year old, battery and alternator are botha a year old, just did a complete intake manifold gasket change, cleaned the manifolds and TB. ive read this whole thread and doesn't seem like new injectors helped anyone.

if any1 has solved this problem that so many thirdgeners have please please please post how you fixed it!

UK Speedbird

Hi Guy,

Can't speak for anyone else but the first time this happened to me it turned out to be small bits of rubber ('O' ring seals) from the fuel pipe inlet stuck in one or two injectors. I eventually ordered six new ford injectors from Southbay and it cured the problem straight away. (plus the original OEM injectors are known to be pants anyway and they were nearly 20 years old by then also.)

I'm currently looking at the other problem I've now got (see above posts^^) which appears to be the opposite problem involving a high idle and missfire. I'm pretty sure this is a air leak in the gasket between the lower valley intake manifold somewhere, but thats my problem.

I think the fact that you have problems when you pump the brake pedal could be a clue here. The hydraulic side of the braking system plays no part at all in the running of the engine but the brake booster just might. I think the IAC is trying to correct the idle when too much air is entering the system hence the unstable idle which goes away when you unplug it.

That's deffo saying an air leak to me somewhere, have you checked for leaks as someone pumps that pedal for you? Get some carb cleaner and squirt it round your vac hoses and manifold see if you get an increase in rpm's.

Sure someone with more experience will have a better idea but thats my worth, hope that helps.

All the best, Speed.

thatoneguy5x

thanks for the reply, i'll try to get some1 to pump the brakes for me while I check for leaks. I was actually having this problem a while back and it just went away on its own. I really want to get to the bottom of it this time.

sheltonw3

I'm in the same boat here, I just did a full tune up and found a leaky fuel hose at the smog, and it runs choppy too, but I also notice I was getting back fire noises too!
I already swapped the EGR, and the idle air control valve on the throttle body, I stepped on the brake twice and put it gear and it died, then started it up again and the idle drops very low.

sheltonw3

it just might be a bad oxygen sensor???

thatoneguy5x

my O2 sensor was switched out when I did my tune up last year, still has the same problem. I have run seafoam through it twice since ive had the car, its possible that all the gunk that got burned off the engine could coat the O2 sensor and give inaccurate readings. just a theory but I don't want to keep throwing money at parts. it seams like a lot of people are having the same problems.

chops1sc

My EGR valve went out a few years back while it was sitting in the garage (a work in progress). It started out as a leaking gasket (on the valve, not where it mounts) and I didn't have the money to replace the EGR at the time. So I took the EGR apart and welded the holes shut on the base and put the base back on the manifold. It would start and run fine but after warmup the smog pump would try to kick in. This would make it idle rough and almost shut off. I am wondering if this might be the same issue the guys in this thread are having.

decked

To start things off,i am not a new member, i just forgot the email i used and pass...... My problem is similar to Scurry13... Here is my rundown....
the idle fluctuates but within a +-50rpm tolerance and sometimes drops to around 500 every now and then....When i go to stop, the rmps will bounce from anywhere between 150 and 1k rpm and stalles after about 3-4 times of doing this. It happens below 1krpm and above idle speeds(11-15mph). It does this with load(AC on), no load, and neutral. It does it hot or semi cold(started and running down the road).It starts immediately when i put it back in neutral or park. If i start down a slight hill and let the car pull itself to above 11-15mph, the problem starts again and the idle fluctuates and stalls without me giving any input to the car(brakes, throttle, ect...). This problem occurs rain or shine, hot or cold. The car only stalls when under 1k and above idle speeds......

My driving habbits: casual,dont like to "hotrod" unless i get onto the interstate then i pick up to speed quickly to about 75-80mph.

plugs, wires, cap, ICM, all have 30k mi on them an the car has about 60-80k miles on it total i have been running midgrade gas lately and i dropped a can of seafoam and octane booster to see if that helped but no dice.

Similar problems that might help:The car is slightly hesitant and wanted to sputter along the other day but that only happened once but i can see it happening again. Alternator ouput voltage starts around 14.7V and slowly works its way down to just above 13V and every now and then drops to 12V before catching itself and picks back up to slightly above 13V. Oil pressure hangs slightly high after interstate driving Idle is very little affected by these problems. But i am more worried about the Idle than about the alternator output and oil pressure as it tends to correct itself....

Id hate to rear end someone because my car stalled....

decked

Well, i fixed my problem but i think it is a multitude of problems........ I had "forgotten" to change my fuel filter when i did a tune up of my car after it had sit for 7yr and it solved the stalling problem. Now i think i have injector problems since i am having a hesitation problem