420A 95 non turbo - starts hard, rough idle, occasional random stalling

[swilson87]

I guess I should start by saying that I have been on this site for a while, but I have always been able to answer my questions without posting, just by reading about other's experiences.

I have a 95 Talon, non turbo, just picked it up. It is starting really hard, having to try several times. It appears that giving throttle encourages the start, but I may be mistaken. Once running, it idles rough, and needs throttle help to stay running at first, and after about 15-30 seconds it will smooth right out. Once driving, occasionally the car will stall, the gauges momentarily drop, and i have to pump the gas a few times, while in gear, to bring it back to life. Also, not sure if it's relevant, but the heat doesn't blow warm. I'm going to pull the cap and top it off/check for air right now though, which hopefully helps with that.

I can hear the fuel pump coming on when it's supposed to, and I replaced the fuel filter. Any help would be greatly appreciated, as this is my only mode of transportation right now. Thanks in advance.

 

[BK85]

Are you getting the CEL? If so see what codes its throwing. That's a good starting point.

I had a similar problem on my 420a motor.

I pulled the throttle body and cleaned it with carb cleaner while checking the throttle position switch and the idle control motor, both mounted on the throttle body. I had to clean it a couple of times but it seems to have fixed the problem.

A lot of the 420a idling problems are due to a dirty TB.

Good luck,

BK85

 

[swilson87]

No check engine light. I have an aftermarket throttle body, that isn't really that old. Would that cause such hard starting though? I'll pull it apart and clean it, but that doesn't seem like it would be a likely cause of the hard starting to me.

 

[BK85]

Yeah, I was mostly thinking of the rough idle and stalling problem.

How about vacuum leaks? That will drive the 420a nuts.

It's odd that you don't get any CE codes. That kind of problem really should of thrown some kind of code.

If you know someone that is running a 420a motor you could try swapping in some known good parts for a test, like a stock TB or the ECU, etc.

BK85

 

[IgotBoost91]

clean your iac and egr and swap out fuel filter

 

[TotalEclipse21]

A faulty coolant temperature sensor can be the cause also.

 

[swilson87]

I put in a new fuel filter. Tried another ECU. My car has a Venom intake manifold, so there are only a couple vacuum lines coming from it. I looked them over and they all seem fine, I unplugged them one at a time with the car running, and the car went nuts each time, so I think they are okay. I'm wondering if the CEL burnt out, because I didn't notice it come on with the key on. I'm going to have it pulled for codes. The coolant gauge works fine though, could the sensor still be bad?

My brother has another 95 ESi, so borrowing parts to test is no problem.

I'm going to try seafoaming the fuel system. The more I think about it, the more my symptoms sound like they may possibly be a clogged injector. I'll post the results in a few hours.

 

[swilson87]

Alright, I'm getting code 12 and 25. 12 is because I had the computer unplugged. 25 - "Target idle not reached (+/-200 r/min) " Any suggestions as to why my car is so hard to start? I'm running out of ideas.

EDIT: I cleaned the IAC and throttle body as well. It hasn't seemed to help anything.

 

[Awesomewhitedude]

Update?

 

[skunkdeez0079]

same problem and still no one has actually solved this issue this sucks