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Injector replacement

913 Views 26 Replies 10 Participants Last post by  Nick Micale
I just replaced my stock injectors with a set of 30# tomco green stripe. The car ran fine before the swap. Now I can barley get it to run unless I remove the TPS sensor connection. Upon removal the engine will smooth out and idle at about 2k rpm. Where could the problem be????
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hey cool your from mesa?? awsome. anyway where did you buy the injectors off of? if you bought them off cottons jack is a real cool guy i'd call him up.
Hate to ask but did you forget to hook the PVC up? Only thing I could think up that you would need to disconnect to install injectors.
You put all the injector harness connectors on the right injectors? You did not remove the tps harness or iac harness for any reason?

What's your vacuum reading? PVC hose off sounds logical to me.



Originally posted by Steve Wood:
You put all the injector harness connectors on the right injectors? You did not remove the tps harness or iac harness for any reason?
Nope

What's your vacuum reading? PVC hose off sounds logical to me.
The hose appears to be connected, but I have not checked the vacuum.

Is the fact that it runs without the tps connected have any signifcance that comes to mind?
Check the TPS volts. Sounds like it may have moved. Not sure, but it probably goes to a preset value when unplugged? Steve?



yeah, I think it goes to 2.6 but I did not look it up. That tells the ecm the throttle is open and it pours gas to it. As the butterfly is not open, it will be super rich.....I think...


Sounds like a vacuum leak...

What did you disconnect when you swapped them?



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Yeah, that's a real high idle...if you are going by a real tach. The factory tachs are usually way, way off. You got a real tach (Az, not Steve)?

You should have rebuilt the engine while you where changing injectors.




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Did you remove the EGR when you pulled the fuel rail. If it were to get damaged or not hooked back up correctly it'll kill yer idle too. If your chip doesn't use EGR (i.e. MaxEffort), I'd block it off.
good point..I went thru a bout with not being able to get the egr gasket sealed and it screwed the idle.



Originally posted by Steve Wood:
good point..I went thru a bout with not being able to get the egr gasket sealed and it screwed the idle.
Did not remove the EGR. Put a vacuum gauge on last night and when i could get it to run it read about 18. I removed only removed the coil pack to replace the injectors. I reused the existing injector harness as it appeared to be in good shape. To keep the car running I need to keep moving the accelerator pedal rapidly.
Are your plug wires all on the right plugs/posts?
And I thought I had bad luck.
Vacuum sounds good.
Sounds like a fuel problem.
Do you have a fuel pressure guage?
You think something could have happened to the FP regulator?
If all of the above is OK you could swap injectors back and see if it is the new injectors.
Originally posted by ES:
And I thought I had bad luck.
Vacuum sounds good.
Sounds like a fuel problem.
Do you have a fuel pressure guage?
You think something could have happened to the FP regulator?
If all of the above is OK you could swap injectors back and see if it is the new injectors.
Fuel pressure is good, I think I'll try swapping the injectors out this weekend. That
won't take long and I'll know for sure if I have a real problem to look for. I have talked to some people who say that the injectors iam using can be problematic. I guess I'll soon know.
Were they new ones?

Those have been used widely as stock replacments.



Originally posted by Steve Wood:
Were they new ones?

Those have been used widely as stock replacments.
They are brand new. Don't know what else to try. I looked over hoses and wires and everthing looks ok. Last night with TPS off it was idling at about 800rpm in gear. The car is driveable as long as I do not connect TPS. As soon as the service engine light comes on (takes about 30 sec after TPS disconnect) the engine smoothes out.
your tps is reading normally....42 or so at idle and increases smoothly as you depress the pedal?



Originally posted by Steve Wood:
your tps is reading normally....42 or so at idle and increases smoothly as you depress the pedal?
It is set ok but I have not checked how it is operating as I depress the pedal. I guess that could be a potential issue, I don't know how it could have got damaged though.
I don't think he would know his tps reading if it is not connected. And the service light is maybe from no change in the tps sensor because it's not hooked up.
Could he be sucking wind from the injectors not being seated correct or a screwed up O-ring ?
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