E30 Build Thread

oof, this is quite the frustrating issue. Maybe someone else can shed some light. all i know is that if pinching the return worked that means fuel backed up and had enough to feed the injectors

All you need to solve this problem is an extra pair of vice grips...

Went back to the garage update coming.


Cj, don't think it didn't cross my mind...lol.

what the crap. lol. coolant leak..... tehehe. hopefully it holds out on the test drive. if not. pluck the engine and swap in a giant hamster ball

Idk what's up, but it idles just fine! Granted it doesn't have an air filter so it's all not quite together and perfect yet.


Probably won't drive it tonight, need that filter and need to bolt some things back up, oil change too.

I think possibly the FPR was "stuck" all I did was unplug and re plug the vacuum line from it.

my head hurts from reading all of that...

matt,

there s/b 2 pumps on this thing. 1 in the tank, 1 on the fuel line. the in tank unit is a sending (feeder) pump, while the inline pump is the one that builds the higher pressure.

iirc there are mods to convert to a single pump, but that is neither here nor there. at least not now...

take your fuel pressure readings. if you are not running without the return line being pinched off, then i say fuel delivery is an issue. your pump may be running, but it may not be building enough pressure to allow the vehicle to run properly.

the fpr uses vacuum pressure to reduce the fuel pressure, and when accelerating hard, the vac drops and fuel pressure increases because the diaphram inside closes.

on average, the fuel pressure should increase about 10 psi when the throttle is snapped.

this is how you can check for fpr operation.

so i suggest checking fuel pressure and fuel pump operation. the in tank pump.




df

my e30 had dual pumps aswell, i initally though that was one of its issues Sadly it wasnt for me. good luck matt!

What was your issue Joe?


Df, how do I check the in take pump? It has to be working because a ton of fuel is flowing out, correct? I can also hear the in line pump working.

Scratch the whole "I fixed it" part. Still not quite right, going to get a fuel filter air filter and oil filter tomorrow. Install, test fuel pressure, and report back.

if both pumps arent pumping, then the fuel pressure will be low and slow. like lola...

as for how to make sure the supply pump in the tank is working, unplug the inline pump and read the pressure.

not sure if there is a spec for that pump or not, though. never owned an e30.


df

This thread makes me Want to never own an E30...

never understood the reasoning behind 2 pumps...but i believe there is a retrofit to a single pump.



df

Will do! Thanks Df.

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Did the air filter and fuel filter, really no change. I forgot the fuel pressure gauge, DOH! Stupid me.


FWIW, I could not blow through the old fuel filter, however I could the new one.

Originally Posted by FenderBender

Did the air filter and fuel filter, really no change. I forgot the fuel pressure gauge, DOH! Stupid me.


FWIW, I could not blow through the old fuel filter, however I could the new one.

hmmmmmmm. I bet you can't wait to get it running so you can sell it

Lol MAYBE!

Alright, real fuel pressure updates, sorry for the videos, some are quite long.









To sum, fuel pressure engine off in spec, maybe a hair under.


Fuel pressure engine on, 30 or so psi, spec is 43psi or so.

Cricket cricket......

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that's only about 75% of spec, so that could give you issues.

what does the reading do when you remove the vacuum to the fpr?? if it goes up, by how much??

if it doesn;t go up, then i would look at the price of pumps, and possibly the retrofit idea.

replacing 2 pumps to me is such a silly idea. but that's me.

i tend to like simple and clean.





df

I think in the one video I removed the vacuum line and the pressure did go up. What does that mean?

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Means your fpr is working. It reads the removed vacuum line as a drop in vacuum which means open throttle. At open throttle you want more pressure to feed the injectors since the fuel demand goes up.

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I guess I will test each fuel pump tonight and go from there!

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Ill be honest now. lately i have been wanting to buy a e30 and slam it and put some wide wheels on it.


would be my little truck.

Lol you hate them!

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