Yet another crappy idle thread

[jmiedzinski]

Hi Guys,

I'm just losing my mind. Here is a short video from my engine "idling". Current state is:

• All sensors new (IAC, ECT, ACT, TPS, MAF)
• New distributor, TFI (Motorcraft), cap, rotor, wires, plugs
• New fuel pumps (in-tank and secondary)
• Fuel pressure 35-38 psi
• TPS reading 1.02V at rest
• ECT and ACT readings similar ~40k (not sure the exact value at the moment but both within 2-3k)
• New injectors (SKP mid range price from rockauto)
• New ECM (Blue streak electronics reman), however currently swapped back to original as it was even worse with new one
• No significant codes (only EGR which is ok because EGR is bypassed completely)
• New HEGO (o2 sensor)
• Most of the connectors for sensors are new. Questionable ones were replaced.
• Ignition timing set with strobe light at 10 degrees with SPOUT connector out
• New coil
• New FPR (Walker products made in USA)

The car was never running really good from the moment I bought it. I'm working on it from several months. Whole engine and trans were out. I had to replace all rotten expansion plugs and mitigate several leaks. I was also rebuilding suspension with DJM lowering kit (dream beams and rear axle flip). Anyway, I did not have chance to drive it much, but there were moments it was idling fine. Recently things got worse and after much debugging I found that one injector was damaged and stay open all the time dumping fuel to the intake and bleeding off the pressure immediately. I swapped this faulty injector to the old one which maybe wasn't great but working. I had to change oil because all the fuel dumped into manifold ended up in oil.
The current situation is clearly visible on the video I posted. By the smell it is still running extra rich, but I'm sure no injectors are leaking because fuel pressure is steady at around 38 psi. Last thing that I have in mind is to check ECT reading at the ECM connector - maybe there are some damaged wires. Other than that I'm completely lost and out of ideas. Please, point me in some direction guys, because I dumped a ton of money into this rig, especially that I live in Poland and each single part I buy I have to import from US paying extra shipping + duties + taxes. I don't regret it yet because its a cool looking car and I always wanted to build a dropped patina truck, but I don't know what else to do/check/replace before I tear up the engine which is last resort really.

Best regards,
Jerry.

 

[gaz]

@jmiedzinski
I have experienced 100% failure of Blue Street components.

 

[jmiedzinski]

Checked compression: 150-155 psi across all six cylinders. Also checked connectivity from ECM connector to ACT and ECT. Clear readings 47.7kOmhs at 53F. Any ideas, please?

 

[racsan]

vacuum leak maybe?

 

[Uncle Gump]

I watched the video...

It idles like there is a dead miss. My suggestion is to get it running and pull the plug wires... one at a time from the spark plug... and note changes to idle quality. If you find the cylinder that doesn't change the water it idles... you've found the cylinder.

You've changed a lot of parts...

Replacement parts are a total crap shoot these days. I've heard a bunch of stories of crap injectors. Hope you didn't pitch the originals... test and clean them... and put them back in.

 

[jmiedzinski]

Replacement parts are a total crap shoot these days. I've heard a bunch of stories of crap injectors.

Hi, Uncle Gump, thanks a lot!
I removed the injectors and sure enough, two of them are completely dead and do not respond for signals. Also, internal resistance is through the roof. Now, I have the two sets of other injectors. One which appears to be original contains six Bosch 0280150727 injectors. From the tech specs they should be 14,5Ohm internal resistance and should output 108g/min@3bar. I also have similar set of Bosch 0280150414 which are dedicated to '90 BMW Series 3 and 5 and they're 15.9Ohm internal resistance and flowing 120g/min@3bar.
Actually the latter were installed in the car when I bought it, but I decided to buy set of new ones because knowing they're not dedicated to this truck I though it may be the issue of poor idle and misfires.
I tested both sets with multi meter for internal resistance and did the basic on/off test and they're appear to be working and up to specs. My question is whether the 1.4Ohm difference in internal resistance and 12g/min difference in flow is something that may cause any issues or these sets are similar enough ? I'm asking because this original set looks very worn out and I may end up being forced to use these from BMW. I ordered this fancy Autool injector tester/cleaner so I will clean them out and test them thoroughly, but I'm just curious what is your opinion.

 

[jmiedzinski]

And the shitty ones I bought were SKP SKFJ712, so keep in in mind guys BTW, is there any reliable brand of injectors that have the right ones for 2.9 other than Bosch which seems to be unavailable anywhere I search ?

 

[Uncle Gump]

I've heard a couple people claim ACCEL injectors worked very well... but expensive.

I myself bought a set of used Motorcraft injectors. @Shran has a name of a company that tests cleans and calibrates them i plan on sending them too. But I can't remember the name. Maybe he can share his source again. Then I will ship mine off to them.

 

[Shran]

Mr Injector

We service and restore gasoline fuel injectors and gasoline direct fuel injectors to like new performance.

www.mrinjector.us

 

[rusty ol ranger]

Mine did this too. I had a bunch of failing/failed injectors.

I ran cheapo Ebay ones and 5 years later they still seem fine. Maybe i got lucky.