leaky injector?

[John B]

My '91 2.5 turbo idles a bit rough and occasionaly dies and won't restart for a few minutes. Could this be a leaky injector?

[John B]

Anyone?

[jre97]

It's possible does one spark plug look like it's been running really rich? The first thing I would check would be the codes and maybe the hep.

[turbovanman²]

Could be bad grounds, bad HEP, dirty throttle body, dirty AIS, bad AIS. Any codes. If all checks good, try giving the throttle blade screw 1/2 turn or so.

[puppet]

HEP ... gets hot and won't work till it cools.

[TurboJerry]

When it finally starts, do you get a James Bond cloud of black smoke out the exhaust? I actually never had a car idle rough with injectors that leak down. Just the hard starting and the smoke when it lights.

[John B]

No codes, no smoke, new AIS (and everything else). I've replaced every sensor twice, except baro sensor (once).

[TurboJerry]

Well, It's not the injectors. The Idle AF ratio is lean on a SBEC setup. So if it has a ported head, it will idle rough. My '91 does........... I want to say HEP but you don't get code 54? Maybe try one for giggles. I find the cheesy aftermarket ones to be pretty bad. I actually get used Chrysler ones from the JY. They're the best for me sofar...... If the injectors are clogged, I would ask if the AF ratio at WOT is lean or not? If it's lean, then clogged injectors if the FP is good at WOT. It's pretty rare to have them clog, but it does happen. I hope this helps..... Keep us posted......

[John B]

So if it has a ported head, it will idle rough. My '91 does........... Keep us posted......

I have a Menegon head. How does that cause bad idle? I can't believe I have spent so much money on sensors for nothing. Oh, well, I have lots of spares and to sell now... Let's see, AIS, TPS, MAP, Baro, temp, hep, coil, SDS, Fuel reg,

[turbovanman²]

I have a Menegon head. How does that cause bad idle? I can't believe I have spent so much money on sensors for nothing. Oh, well, I have lots of spares and to sell now... Let's see, AIS, TPS, MAP, Baro, temp, hep, coil, SDS, Fuel reg,

Loss of velocity due to the larger runners. I noticed my ported G-head the idle is rougher. They always say, diagnose first before you throw parts at it,

[TurboJerry]

The SBEC cars have a lean idle mixture to begin with because they are SEFI. So it needs to be a little richer to smooth out the idle, but the dieing and hard starting sound like something else....... Loss of velocity is the problem......

[John B]

Is it possible that grinding the bolt bumps out of the intake runners could be contributing to this idle problem? They do coincidentally cause a venturi effect right at the injectors.

[turbovanman²]

Possible but who cares a lumpy idle. I always was concerned but now mines a bit rumpy, you can hear it in the exhaust and the engine and people look at you like-WTF? hehehee

Stalling, try adjusting the throttle blade, try opening it a bit more or alot more.

[TurboJerry]

I thought the big problem was stalling and hard/no starts?
I agree, my manifold has no "bumps" either, and I know that doesn't help the smoothness of the idle.