IROCBOY

Im having a problem with my 305 tpi. With the clutch pressed the engine revs before dropping in RPM. and if i come to a stop the engine lopes enough to stall it occasionaly. the engine also hesitates while attempting to accelerate from a stop. all this occurs only after the engine has been running for a while. I have no Vac leaks. I have replaced the IAC valve, the EGR Valve, and the PCV valve. I have also recently replaced all of the gaskets for the tpi system. my problem continues. any help is appreciated

pandin

I would pull some of the plugs and see if you are rich at idle, could be loosing an injector or the spark.

IROCBOY

the only reason i dont think its an injector is that its not just a rough idle so much as it is a lazy rpm jump and drop. like a sensor going or something giving bad feedback to the computer which is trying to compensate for it. sometimes i can drive it for a half hour and it runs fine until engine is warm. i will check plugs though. had the injectors out the other day and looked fine but we know that doesnt mean much.

CamaroRider

Maybe it is time to check and monitor the fuel pressure. Possibly the fuel pressure regulator is acting up or something related to the fuel pump. The ECM would have to try to compensate for that and who knows what it might try to do. Hate to see such an unsolved problem !

RMK

Does it ever cut out when trying to accelerate from a stop?

IROCBOY

Nope, just hesitates sometimes. I checked plugs and changed them as i went. most were a little wet without running the engine for about 10 hours. Im thinking more and more that fuel pressure regulator or injectors might be the right tree to bark up.

midnight'91

hey man im having the same problem you are. except mine acts up when i first start it, it doesnt like to idle and lopes enough to kill it. when the motor warms up it runs fine. i was told that it was my fuel pressure regulator. im short on cash so i havnt replaced it yet.

1tpi

Check you fuel pressure before you
replace the regulator

RMK

Ohm test your injectors and post the results. I have a simmilar issue when my car is warmed up where it hessitates off the line and the rpm dropps. My base idel is too low for a start as I had to set the idle valve with the car in park instead of drive as I was on my own.

IROCBOY

Ohm test results
1 16.5
2 10.0
3 14.3
4 12.5
5 16.4
6 15.9
7 8.9
8 8.6

RMK

From what I've been told they should be within 5 of each other. A few of them are on the low side.

CamaroRider

IROCBOY:
I suspect they should be measured when cold and also measured when hot.
Record the results so you do not have to question the measurments later.

RMK:
I read where another 'single tech' would set his idle a little higher and then jump in the car and place the car in gear while watching the idle RPM. If it was still too low he would put it in park and jump out, increase the idle then jump back in the car and put it in gear. Over and over until he got what he wanted for idle speed while in gear. Sounds tedious but he accomplished his goal.

RMK

CamaroRider,

Thanks for that. I had been thinking about trying that in my head and will give it a go tomorrow and see if that solves my issue.

pandin

It is time for different injectors, anything under 10 is not good. Was this checked hot or cold? They are usually worse when hot.

IROCBOY

They were checked cold. not ran for about 20 hours. Any recommendations for injectors? not looking for too high performance. just street driving but want good reliable parts.

RMK

Just out of interest. If it is the injectors, why does it stumble off idle and not when squeezing on the gas from a roll?

IROCBOY

It does sometimes from a roll too but i think my engine remains pretty ballanced during the engine lopes and its hard to notice

IROCthings

right now my car is having a major problem. i replaced my old fuel pump because my car wasn't getting enough fuel pressure to stay running when i replaced it it still would not stay running. i really don't know what it could be. it gets fuel right away i have the clear rail in between my lines to check it. and idk what the **** it could be. I gave up. it's currently at a shop.

pandin

Re: fuelinjectorconnection.com
i put the injectors in also from Jon at FIC.. Really knows his stuff. I got the design 3 Bosch and installed as they came. No leaks and they seal perfectly. I can feel a big difference in my throttle responce and idle. Plus I have checked my mileage and i'm up two mpg.. Jon spent all the time I needed on the phone. Almost an hour. I was going to get Accel from summit. I'm glad I got these.


I have no personal experiance with these but have seen many happy posts.

Re: are the injectors bad???
The 19lbs from FIC are only $169 and they come with a 3 year warranty. They have been modified to have the same installation height as the stock injectors.