7A running bad

[ventt]

Hello!

I'm having troubles with my 7A engine.
Basicly, if it's cold, then it won't rev at all, just wants to die and if I hit full throttle, it'll start misfiring and spitting back...

Here's the video too I made today:

https://www.youtube.com/watch?v=OUwJC20nGu4

And if the engine has idling about 10 minutes, then it'll rev to 3000rpm and then the same symptoms, misfiring and spitting back.

https://www.youtube.com/watch?v=UX7E3TYwpf0

I've done:
* New MAF
* New Bosch injectors
* New Fuel pressure regulator
* New fuel filter
* Checked the lambda with multimeter (steady 0.4v)

Engine belt is in correct position, idle is fine and starts good, won't matter if it's cold or hot. Spark plug wiring is ok too, didn't feel anything electric if I touched them while running. Exhaust gases smell very rich, spark plugs are black, though everything related to mixture adjustment components are okay. Fuel pressure is 4bar (because of the a little bit bigger injectors than the original ones) when full throttle. No vacuum leaks also.

Also I can't read blink codes. Does it really have to be diode or a brake light will do?

What should I do?

[Error404]

Sounds like you are running the wrong injectors

[ventt]

Sounds like you are running the wrong injectors

It did the same thing before changing the injectors

[SA BOY]

Change the temp sender on the back of the cylinder head.

[Martin62]

I had sort of similar symptoms with my 7A and it turned out to be an knock sensor failed as suggested by a member on here.

I have to say though, it didn't sound as severe as in your video

I made a code reader with a diode which confirmed it.

[ventt]

Change the temp sender on the back of the cylinder head.

If I disconnect the plug from the sensor, it just starts idling about 1100rpm. I assume that the sensor is working.

I had sort of similar symptoms with my 7A and it turned out to be an knock sensor failed as suggested by a member on here.

I have to say though, it didn't sound as severe as in your video

I made a code reader with a diode which confirmed it.

Allright, next time I'll try with a diode then.

Engine ran fine before the swap on B3, changed the belt, water pump and some gaskets. After putting it on the B4, been pain in the *** for a half year now...

[Mikes2]

What fuel pump are you using now

[mcandmar]

Sounds like you have the wrong firing order, double check the plug leads on the distributor cap in case any of them got mixed up.

[Mikes2]

Also forgot to ask, did you bypass the resistor pack for the injectors

[ventt]

Sounds like you have the wrong firing order, double check the plug leads on the distributor cap in case any of them got mixed up.

I'll check them in the weekend and update this thread.

Also forgot to ask, did you bypass the resistor pack for the injectors

Yep, I did.

[theyagaraj]

Hi
Check for cracks in exhaust manifold ...

I had similar symptoms including black smoke and after checking everything we found it was cracked exhaust manifold

Theyagaraj

[Azimut]

Normaly lambda should jump from about 0.2V to about 0.9V in a 0,5-1sec . if you have steady 0,4-0,45V it seems to be your lambda is dead . And when you check your lambda with multimiter, you should not disconnect it from the wiring, just pull rubber protection off and measure from the connector.

[Bowie69]

Unbolt the knock sensors and put to one side, see if you get the same symptoms.

[ventt]

The firing order is fine, disconnecting the lambda probe made it a little bit better, so I tried to change it but half of it snapped inside the exhaust manifold... Gotta figure out how to get it out of there.

Also tested the compression of the engine:
1cyl: 14bar
2cyl: 13bar
3cyl: 15bar
4cyl: 15bar
5cyl: 15bar

[steve briance]

have you checked for MASSIVE air leaks?
I have been working on my 7A recently and managed to knock the vaccum pipe connection off the back of the inlet manifold, this meant my brake servo (ive done the conversion) was open to the air and it ran exactly like yours seems to be. struggle struggle struggle then at 3000rpm away it goes!

check all the rubber hoses, especially the inlet pipe to the throttle body, it may well have a big split underneath that you can't see...