Hey guys, so last Saturday I picked up a project car E28, and was having quite a few issues from the get go. When I got to the guy's house to look at it, it was perfectly fine ran strong, idled well, was just a little bit noisy. He mentioned it had a cold start problem, so I presume he used a block heater before I got there.
The main problem I've been having is a combination of shitty workmanship in the engine and a vey rough idle, due to what I believe is a fuel injector not firing properly. The first issue I found was a possible vacuum leak, there was one hole 'taped' up on the right side of the engine, about 5inches below the air intake boot, and the other one (which I assumed was missing a hose that ran from here) was to a second hole underneath the cylinder and fuel rail in the block. Upon plugging a makeshift hose in these 2 holes the idel seemed to even out from doing 800-1300 into a solid 950-1000. I'm going to put all of my questions at the bottom of this post so it is easy to navigate.. With that 'solved' for the time being brings up the next problem, any time I try to start it without gassing or pulling the throttle, the car stalls after 5 seconds, I disconnected the fuel-injector hose and it only spurted fuel out when the gas or throttle was being pressed but if the car is an electronic fuel pump, is should be spurting at all times...correct? I sealed the fuel pump back up and decided to change the injectors, went to my local auto mart and they pointed out the "Denso Iridium TT" plugs were what I was looking for, after removing the original sparkplugs, I noticed that Cyl. 3 and 4 were running a little rich and had a white coating on the tip. After gapping all of the Denso's(gapped at .030) I realized they also did not have the right kind of tip to match the original, so I am unsure if they are even for my car at this point. Anyways, I put them in and the car's idle was horrendous, VERY shaky and rough. (Since filling the Vac hose mentioned before, the car is able to start and run.) So my deduction is the sparks aren't jumping to and from the plugs and wires.
Common fixes I have tried:
I changed the Trans fluid
I cleaned the ICV
I cleaned the Airbox / filter
I Fixed any Vacuum leaks I found
Checked the battery and it put out a solid/non fluctuation perfect 12.5v
TL: DR; Bought a 528e with rough idle, fixed many common errors and replaced spark plugs and the idle became even worse.
1. Does anyone know what that hose is called? Is it just regular silicone hosing? Do I need a special replacement? etc..
2. Does the 528e have an electric fuel pump? Should it be sending fuel at all times or only when the throttle/gas is being pushed?
3. Has anyone used Denso Iridium TT plugs? Did you need separate wires? What did you do about the blunt tip instead of it having the 4 prongs?
Does anyone have any idea what could be causing this and how to resolve it? I plan on throwing the old spark plugs in while I try to figure out the rest, but I am almost positive I should look into replacing the ICM since it seems like the fuel injectors are being shut off but am also looking for some other fixes in case this doesn't work.
Any help you can direct me to or give me is greatly appreciated, thanks!
The main problem I've been having is a combination of shitty workmanship in the engine and a vey rough idle, due to what I believe is a fuel injector not firing properly. The first issue I found was a possible vacuum leak, there was one hole 'taped' up on the right side of the engine, about 5inches below the air intake boot, and the other one (which I assumed was missing a hose that ran from here) was to a second hole underneath the cylinder and fuel rail in the block. Upon plugging a makeshift hose in these 2 holes the idel seemed to even out from doing 800-1300 into a solid 950-1000. I'm going to put all of my questions at the bottom of this post so it is easy to navigate.. With that 'solved' for the time being brings up the next problem, any time I try to start it without gassing or pulling the throttle, the car stalls after 5 seconds, I disconnected the fuel-injector hose and it only spurted fuel out when the gas or throttle was being pressed but if the car is an electronic fuel pump, is should be spurting at all times...correct? I sealed the fuel pump back up and decided to change the injectors, went to my local auto mart and they pointed out the "Denso Iridium TT" plugs were what I was looking for, after removing the original sparkplugs, I noticed that Cyl. 3 and 4 were running a little rich and had a white coating on the tip. After gapping all of the Denso's(gapped at .030) I realized they also did not have the right kind of tip to match the original, so I am unsure if they are even for my car at this point. Anyways, I put them in and the car's idle was horrendous, VERY shaky and rough. (Since filling the Vac hose mentioned before, the car is able to start and run.) So my deduction is the sparks aren't jumping to and from the plugs and wires.
Common fixes I have tried:
I changed the Trans fluid
I cleaned the ICV
I cleaned the Airbox / filter
I Fixed any Vacuum leaks I found
Checked the battery and it put out a solid/non fluctuation perfect 12.5v
TL: DR; Bought a 528e with rough idle, fixed many common errors and replaced spark plugs and the idle became even worse.
1. Does anyone know what that hose is called? Is it just regular silicone hosing? Do I need a special replacement? etc..
2. Does the 528e have an electric fuel pump? Should it be sending fuel at all times or only when the throttle/gas is being pushed?
3. Has anyone used Denso Iridium TT plugs? Did you need separate wires? What did you do about the blunt tip instead of it having the 4 prongs?
Does anyone have any idea what could be causing this and how to resolve it? I plan on throwing the old spark plugs in while I try to figure out the rest, but I am almost positive I should look into replacing the ICM since it seems like the fuel injectors are being shut off but am also looking for some other fixes in case this doesn't work.
Any help you can direct me to or give me is greatly appreciated, thanks!
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