HELP! Rough idle,smoke..new motor..SAME PROBLEM?
 

I bought a 87 T2 from someone that had 214k miles on it. It smoked (bluish smoke) with a nice scent of gas. He felt the APEX blew and with the amount of miles...I didnt think much of it. He said it ran fine untill he hit a puddle one day (turbo had no filter)..bame...it started running crappy. When I pulled the motor, all APEX seals where intacted.

So heres the deal...I have a recent rebuilt motor (5k) I installed, got everything hooked up and started it up...RUNS THE EXACT SAME WAY! I first have to get it started by disabling the fuel pump and pump'n the pedal. After it starts, I enable the pump. It blows out a lot of bluish smoke and smells real rich...and of course, is barely running.


WHAT COULD IT BE?

I have cleaned injectors, TPS is calibrated and timing is correct.

Can a bad turbo cause it to run this bad? Is there any electrical problem (coils, pickup on CAS) that can be bad or even the ECU? I found a few things on blown turbo's, but I really need help as I'm my is related to a new motor.

its burning off all the vasoline that you used and all the assemb ly lube. It should stop after the first 600 milrs of driving.:)

Bad afm? bad vacuum leak? bad wiring causing one or more injectors not to fire? fouled plugs? bad ecu? fuel pump?

Blue smoke could be old contaminated oil in the exhaust needing several hours to burn off...common after an engine swap or rebuild. Rotaries should also smoke upon first startup, so if it is never running long enough to warm up all the way, I would expect to see smoke on startup.

Lots of things could be at fault.

I appreciate all feedback, but to better help...heres everything I can think of saying to elliminate things.

Every vacuum line is new includding spider to oil injectors.

All new teflon lines to OMP

All new hoses

All new injector connectors, soldered not crimped.

Any area of the harness found dry or questionable....was redone and double checked.

The motor has been broken in, it was ran for about 5k before I bought it. (person
unknown).

Motor compression total is 113 with street port.


What can I do to test AFM? Its a stock ECU, no piggyback.

UPDATE...still barely runs, no power and very rich.

LEAD coil has lots of spark

CAS resistance within specs

Resistor at passenger side near AFM within specs

Dont know how to test AFM, but I read the brown/white wire should have 4 volts and it does.

Is it possible to have spark and still have a bad ECU? I cant think of anything else that would cause it to run like this.

If my turbo is bad, would it run like this?

The turbo has nothing to do with how the car starts, idles, runs, and responds in neutral. You could take it totally off and put on an NA manifold and not change anything. I think you have a preexisting issue with a component that was reused such as a fuel pump, regulator, injector, etc.

I was just about to say the same. I had the same problem until I switched out the fuel pump.

I too am right there with you. I just wasnt sure if I could elliminate the turbo as a cause...thanks for clearing it up.

This is my suspicion, the las guy had just a screen over the AFM. He states it ran great untill he hit a large puddle of water...then it ran imediately as it does now.

So....I think its the AFM, I just need reasurrance from you guys/feedback.

Can the AFM make it run like this? Its like the engine is just dumping a insane amount of fuel in causing it to hardly run. The AFM plays a large roll on this correct?

AFM's are hard to conclusively test, the best thing is to just throw another one from a known working car on and go from there. IF you've got a buddy with a running car line them up and start swapping important sensors...tps, water thermosensor, ecu, fuel pump, afm, etc. could even be a wiring harness issue. These sorts of things are hard to accurately describe and even harder to track down.

Well today I got a hold of a AFM and it didnt make a bit of difference. I drop'd the exhaust to make sure I didnt have a backed up exhaust system. I tested all contact points I can think of. Tested the EGI fuse box for perhaps bad contacts/resistance/Voltage...all ok. I took apart the ECU, grounded myself and looked and all solder points and resistors...visually ok. The thermo sensor is swapped, the TPS is in spec (no drop during sweep) and my injectors where just serviced.

I have two questions....

What can I use to know if I have a ECU issue if I know no one to barrow one from?

Can the injectors resistor box still be bad if the resistance is in spec of the manual? I'm wondering if this is causing the flooding. The motor wont even go above 2k when it starts....like its choking, drowning.

Nothing, unless you can locate a voltage that the ecu should be outputting and isn't. There is a big chart of input and output voltages in teh FSM.

No. It's failure mode is an open circuit which does not allow one or more injectors to fire.

Man your fast...I just posted.

I guess I will have to bite the bullet and buy a used ECU, I'm getting despirate now..I just want it fixed. Thanks for your help.

STILL NOT RUNNING!!!!

I now have changed out the ECU and the AFM, the car still barely idles.

I have to disable the fuel pump to get it started and the exhaust tips are wet from gas.

I checked everything I can think of.

If a fuel pump or filter is bad....would it create these symptoms? Smpke and bad/no idle?

I'M SO LOST.

You need to check fuel pressure and primary injector fuel delivery. To do the latter, remove the upper manifold, pull back the lower rail with injectors and wiring intact, use some wire wrapped around in an X and circle pattern to hold the injectors firmly in the rail so they dont pop out under pressure. To begin with, put a towel or cup or tray of some sort under them. Turn your key on. Either have someone crank the engine, or remove the CAS, plug it back up, and give it a spin. This should pressurize the fuel plus trigger the injectors. You want to see strong puffs of fuel from each in alternating pulses. A dribble is not enough. A dripping injector is bad also.

IF this checks out, then you need to do a volume test as described in the FSM...you are already set up for it, but you need a spare injector plug and about 4' of wire plus a measuring cup that reads in CC or mL (same thing). UNplug the stock wires from the injectors. Install your test plug and run one lead to ground. Now turn on the key and jumper the yellow test connector by the afm with a small wire to turn on the pump. Using a stopwatch, touch the other test wire to the battery positive post and time 30 seconds of injector spray. At the end of that time, remove power from the injector and turn the key off. During this time you an easily observe the injector's spray characteristics which should be fine and consistent with no drips. Put the cup on a level surface and measure the output, multiply by 2. NA injectors should deliver 450-460cc, and turbo injectors 540-550cc. IF you are more than 5% off either way then I would begin to worry.

To measure fuel pressure you have to tee in a gauge inline with the pressure side (from the fuel filter). I made one from a cheap $20 oil pressure gauge from autozone, some brass fittings from lowes, put about 2" of fuel line on one end, and called it good. I can simply remove the supply line from the engine's metal vacuum spider, install my tester, and connect the hose to the other side, and I'm ready.

fuel pump... try grounding the fuel pump first... my car ran like ass untill i decided to get off my lazy butt and i just added a wire from the ground on top of the fuel pump (my fuel pump was brand new too) and it ran great

the water thermosensor can cause this too if the wiring is bad to that, or the sensor grounds are bad....

the ECU uses the water thermosensor to decide how much to enrich the fuel by when cold... If the ECU doesn't see a sensor, or thinks it's colder outside than it really is, it'll add a lot more fuel than necessary.

I'd also check all your grounds to the ECU.... I've had weird problems when those go... (my GXL was having weird problems, and I noticed that when I unplug the stock ECU and plug in my plug 'n play megasquirt, the megasquirt doesn't even get enough voltage to turn on.... checked my grounds and they were at 2kohms to the chassis... so I ran a temporary power ground and temporary sensor ground from the stock ECU to the engine, and the engine runs perfect...)

This weekend, I am going to check the fuel filter and pump, the injectors are ok since they were just serviced...I think I will also take a look at the line going to the thermosnesor and grounds as well.

Any advice or how/where do I check/correct the grounds at the ECU?

UPDATE..Still nothing!

I changed the Fuel Filter.

I tee'd into line after filter and see about 40 PSI.

I did notice this....Its flooding so bad that fuel is leaking out of the exhaust mani. The hing part that has the large actuator, not the one for the WG.

I pulled all the plugs and cracked it for some time...tons of fuel in there.

So now what? Can it be a bad fuel pressure regulator? Something is causing a insane amount of fuel to enter the engine.

refresh:

injectors serviced
Good spark
timing correct
good compression
all sensors in spec
TPS calibrated
tried 2 ECU's
Tried 2 AFM's
Droped exhaust..incase blocked
New fuel filter
Get 40 PSI when tee'd after filter

Any ideas?

Ok...Dont know how much more I can take...sigh. I tried to do the injector test, but my wires are just too short to get the injectors tested this way. I decided, even though I just had them serviced...I was going to replace them. They did come from a car with 214k miles, so why not?

Well I installed brand new Venom 550cc injectors, still cant get the car to run. I really dont know why else is left.

Anyone? Im getting close to calling it a loss and selling the car for what ever I can get and I dont want to.


If I cant get this resolved...is there anyone in the Sacrameto area that is willing to help?

Have you tested the fuel pump yet?

Make sure it connects well in tank.

I don't know what to say here, it sounds like it SHOULD run fine!

Pressure test the intake manifold to check for vacuum leaks.

Swap ECU's yet?
What's the compression #'s on the new motor?

He did swap ECU's. Sounds like his fuel pump is putting too much pressure all the time...Hmm... damn.
Check the wiring on the pump?

Hey...when I tested the fuel pressure, I had the jumper on the yellow connector by the boost sensor and it read 40 psi when tee'd. I guess I could try it again without the jumper...but I thought 40 was good.

new injectors
Good spark
timing correct
good compression
all sensors in spec
TPS calibrated
tried 2 ECU's
Tried 2 AFM's. <<<<<<<<<<<<<<<< Correction, dont know if the 2nd AFM was good..

Droped exhaust..incase blocked
New fuel filter
Get 40 PSI when tee'd after filter

I'm wondering if there was damage to the turbo caused by rapid cooling from the water? I'm not a big turbo guru but are rx7 turbos oil feed? (why not, every other turbo is...) If you used the old turbo then maybe oil is leaking through the casing, down into the block causing the combustion temp to drop thereby giving you that extra gas. It would explain the smoke too.

Afm's should be watertight. Have you cleaned your connectors? ~rich

[I[Wait a min - did you plug your primary injector connectors into the right injector?[/I]

Man, I could have this thing running in under an hour if it were in front of me.

Have you changed plugs? If not, do so now. Remove the old ones, perform the deflood procedure on my website, and once the old gas is purged and a good bit of oil or atf is injected, put in the new plugs and see if it fires up. Fouled plugs can make one run really rough or not at all.

Also, come to think of it. This is an engine swap. Perhaps the front pullies got mixed up, and the marks are no longer accurate (don't ask, just trust me). You should consider finding a new true TDC mark and find timing from there (5 degrees after the mark is leading timing, which is the mark you are supposed to align to when you stab the CAS and set timing). To do so, remove the rear sparkplugs. Using a mirror and light, align any apex seal in one hole, make a mark on the pulley, then repeat for the other hole. Now find the halfway point between those 2 marks on the shortest side of the pulley. Make a mark. This is your true TDC. Add about 4-5mm to this mark (after TDC will be on the counterclockwise side of the mark you made) and there is your new timing mark. Now realign your CAS to this mark and see if it is better.