Need Diagnosis Help

[BlownMX5]

Hi gang,

I have been taking my time installing my new TDR I/C and PWR radiator. I also bought a header wrap from TDR, which required removal of my hotside MP62. I've got everything back together and I started it on jackstands last Saturday. I ran pretty well but I saw that I obviously had a blower pulley alignment problem as the belt was self-destructing before my eye :1eye:.

So a day or three later I loosened the blower's four bolts and slid it back a bit. I used a straightedge to align the pulleys as best as I could. Put everything back together and started it. Now, the engine will hardly run, it won't idle at all and runs as if the MAF connector is unplugged (it isn't). I know what that's like because I've done it before. I also smell tons of fuel coming out of the exhaust.

I've visually checked everything without taking anything apart again and I don't see any problem. Yes, I have a CEL, but I always do - my EGR isn't hooked up and I haven't checked for new codes recently.

So, my question is: if I somehow managed to disturb the wires coming from the O2 sensor (I have a wideband O2), would the engine run like this, or would it run fine or not at all? Any other ideas of what I should check?

[tann3r]

If you pull the codes we'll have a better chance at helping. tons of fuel coming out of the exhaust could be a symptom or could be normal the car if the car is still warming up. With the codes, we can at least narrow down what we are looking for.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94169 Its on sale and an invaluable tool. I'm currently using this one and while its does not have all the bells and whistles it'll pull the code and there are plenty of places to look and see what they mean. No freeze frame date either, as that is the only feature i wish it had.

[Tom @ Fast Forward]

Sounds more like you shorted an injector wire to ground someplace. The injectors always have 12VDC and the other lead is grounded to turn them on. If you ground that wire all the time, that injector is always on.

I agree about the codes. Could be you have a second code and it will enlighten us immensly.

[BlownMX5]

No additional codes were thrown other than my persistent 28 (EGR) and 29 (not listed on the doc I have). Both those two codes have been present since I rebuilt my motor without hooking up the EGR pipe.

I unhooked the E-Cool injector just in case it was getting shorted somehow and it made no difference. It's truly bizarre - it was running fine and all I did was shove the blower back about a quarter inch to align the pulleys. Then, no runny. I don't even know what else to look at. It sure seems like it has to be an electrical problem somewhere, but the obvious visual inspection reveals nothing out of the ordinary.

[FormerDatsun510Man]

The codes are definitely the best place to start with electical problems. It really makes things a LOT easier :). If an electrical problem is the cause of the car running poorly, you can be sure that it is enough to cause a code in the ODBII. The O2 sensor being disconnected will not make the car run like you describe. I've completely disconnected mine for testing and the car still runs fine actually.

I think some wires got disturbed when you moved the blower most likely. TPS and MAF are the first ones to check, but I recall I had a similar problem that I caught before it became a problem while at BRP. There are wires in a bundle that were rerouted from stock with the blower install. They are the ones that go in front of the engine valve cover and go behind the pulleys/belts for the blower. When you moved the blower back, it is possible the belt is cutting into them. I think that these wires have to do with fuel injection if I remember correctly.

Bill

[BlownMX5]

The codes are definitely the best place to start with electical problems. It really makes things a LOT easier :). If an electrical problem is the cause of the car running poorly, you can be sure that it is enough to cause a code in the ODBII.

This is a '94, so it's OBDI and there are no new codes that I didn't expect to see. However, it helps to get the car running to generate codes. In fact, I can usually drive for some distance before the CEL appears for my missing EGR.

I think some wires got disturbed when you moved the blower most likely. TPS and MAF are the first ones to check

When I originally installed my blower, I extended both the TPS and MAF so I could run them along the firewall. Although the MAF was disconnected during this latest bit of work, the plug just rests on the fender and the wiring wasn't really moved much.

However, the TPS wiring and plug was the most affected since I had to completely remove the blower to install the header wrap. The TPS wire has to run through and between the intake tube and vacuum lines near the TB. Although the car ran fine initially, I suppose there could have been some damage to the plug/wiring that didn't appear until later. I guess I'll check for continuity there first.

[Tom @ Fast Forward]

Look for any wires, like the TPS, that might be touching something hot like the exhaust manifold. Could be melted insulation and grounding out. Could you have put a hole in the hose from the MAF to the TB? That would be an un-metered air leak that would cause poor running as well.

02- crankshaft position (ckp) sensor or circuit
03- camshaft position (cmp) sensor or circuit
04- camshaft/crankshaft position sensor or circuit
05- knock sensor
08- Mass Airflow (maf) sensor or circuit
09- coolant temperature sensor or circuit
10- Intake air temperature sensor (IAT)
11- Intake air temperature (IAT) sensor or circuit
12- Throttle Position sensor (TPS) or circuit
14- Barometric Pressure Sensor
15- Oxygen sensor or circuit
16- EGR valve position sensor or circuit
17- Oxygen sensor (check the fuel and ignition system performance)
23- Rear 02 sensor inactivation error
24- Rear 02 sensor inversion error
25- Fuel Pressure Regulator Control Solenoid or circuit
26- Solenoid valve(purge control) or circuit
28- EGR vaccum solenoid
29- EGR solenoid vent or circuit
34- Idle Air Control(IAC) valve or circuit
41- VRIS #1 solenoid
46- VRIS #2 solenoid
67- Cooling fan relay or circuit
69- ECTF sensor

111- System pass
112,113- Intake Air Temperature(IAT) sensor or circuit
116,117,118- Engine Coolant Temperature(ECT) sensor or circuit
121,122,123- Throttle Position Sensor(TPS) or circuit
157,158,159- Mass Air Flow(MAF) sensor or circuit
172,173,179,181- Heated oxygen sensor(H02S) or circuit
211,212,213- Ignition system
214,244- Camshaft position(CMP) sensor or circuit
327,332,337- EGR function sensor or circuit
411,412- Idle Air Control(IAC) valve or circuit
452- Vehicle Speed Sensor(VSS) or circuit
511,512,513- PCM
519,521- Power Steering Pressure(PSP) switch or circuit
522- Transmission range sensor or circuit
536- Brake On/Off (BOO) switch or circuit
538- Dynamic response test
539- a/c sensor or circuit
554- Pressure regulator solenoid valve or circuit
559- a/c relay or circuit
563- cooling fan relay(high speed) or circuit
564- cooling fan relay(low speed) or circuit
565- Purge control solenoid valve or circuit
571- EGR solenoid valve(vent) or circuit
572- EGR solenoid valve(vaccum) or circuit
998- PCM

[BlownMX5]

Tom, thank you for posting this list of OBDI codes. It is far more complete than the one I got from m.net. I see that 29 does in fact relate to EGR, so that is good.

One of the symptoms I'm seeing now is extreme fuel smell from the exhaust. If it were just a vacuum leak, wouldn't that tend to produce the opposite, a very lean condition? Although, a punctured flex hose is certainly a possibility; every time I remove and replace it, I expect to poke a hole in it.

[fourwhls]

Just a hunch, but I would check the wiring to your MAF. I had a similar issue years ago that ended up being a bad crimp on a pin in the MAF connector.

[Tom @ Fast Forward]

I guess that would be true. Excess air and the ECU sending fuel for what is coming in through the MAF would come up lean rather than rich. If the TPS is stuck in the WOT mode, that would add a lot of fuel, I would guess? As said by fourwhls, the MAF would also be a good candidate for a problem.

[BlownMX5]

OK, I found it. I'm gonna say I had a vacuum leak and then not elaborate in order to save some shred of dignity :redface:.

So, now I'm trying to get the pulleys aligned. When I run a straightedge from one pulley to the other, it looks like it's lined up. But when I add the tensioner (automatic), I have to put washers behind the three bolts or the inside edge of the tensioner pulley rubs the power steering pulley. With the tensioner shimmed, the belt rides slightly off to the rear of the tensioner pulley by about 1/8" of an inch and rubs on the p/s pulley also. In addition, when I sight straight down past the blower pulley, the "inbound" and "outbound" sides of the belt are not parallel. Has anyone else had trouble with this sort of thing? I seem to recall someone saying that they reversed the tensioner pulley, but I don't think that was on an automatic tensioner.

[Tom @ Fast Forward]

My tensioner or BRP's? If mine, I have a solution for it. BRP used a different tensioner assembly.

[BlownMX5]

My tensioner or BRP's?

It's one of yours. Please tell me that the solution isn't to go back to theirs :eek: j/k

[Tom @ Fast Forward]

1) With the tensioner shimmed, the belt rides slightly off to the rear of the tensioner pulley by about 1/8" of an inch and rubs on the p/s pulley also. In addition, when I sight straight down past the blower pulley, the "inbound" and "outbound" sides of the belt are not parallel.

Look at the SC belt and PS belt as they leave their respective crank pulleys. They should be a reasonable distance apart. At the blower and PS pump, they should still be that distance apart. If not, either the PS pump has moved forward or the blower is still to far back. It was not uncommon that the tensioners needed to be shimmed with a washer or two on some of the BRP kits. They were not the most consistant.

2) If everything does line up but the belt is riding off the back of the tensioner pulley, I do believe you can remove the pulley and shim it out a bit with a washer. If that still doesn't work, I can get you the part number of a wider pulley.

3) Was it working before?

[BlownMX5]

Was it working before?

Well, yeah, sort of. I must have just gotten lucky and had it "close enough". I didn't have all that many miles on it before pulling everything apart this time. Also, there was a lot of belt dust in and around the p/s adjustment block from the blower belt that I noticed when I took it apart. So, it must not have been exactly right anyway. It's just that now, I can't seem to get it back in the same spot. I'll get a new belt and I like the idea of shimming the tensioner pulley.

[Tom @ Fast Forward]

Alignment has always been the major feat with those kits. They redesigned the brackets on a regular basis. Once you get it aligned, the adjuster should work.

[BlownMX5]

OK, so I now have the blower all the way forward and the belt is still hitting the p/s pulley. What do you think about shimming the blower pulley?

[FormerDatsun510Man]

Sorry I didn't notice this thread earlier, but I am running what was originally a BRP Hotside kit with the auto tensioner from BRP with pulleys for the crank and supercharger from FFS. What I found was that I needed to add shims to the supercharger pulley, even with the blower all the way forward, because the FFS SC pulley doesn't stick out as far as the BRP SC pulley. I have the BRP prototype tensioner on my setup. While at BRP, I found that those three standoffs used in holding the tensioner bracket were crucial for belt alignment, particularly in holding it at the same alignment when the belt tension changes. They had to be machined perfectly so that their lengths were just the right amount so as to mount the tensioner bracket perfectly square. If not, the tensioner would be at an angle and the belt alignment would be thrown off.

Bill

[Tom @ Fast Forward]

Is the blower pulley one of mine? If so, didn't it come with a spacer? Do you have threads left on
the shaft to allow the pulley to be spaced forward and still lock the nut?

I have a special 1/4" spacer keyed to do the job if you have 1/4" of threads left. Let me know.

Bill, if the belt is properly aligned, my tensioner should work.


OK, so I now have the blower all the way forward and the belt is still hitting the p/s pulley. What do you think about shimming the blower pulley?

[BlownMX5]

My tensioner is an FFS, but the standoffs are BRP. I do have a washer behind each of the three mounting bolts on the tensioner mounting plate. That is just enough to keep the tensioner pulley from contacting the p/s pulley. Bill makes an interesting point: as I mentioned in an earlier post, if I look straight down from the top, the two blower belt sides are not parallel. What I noticed last night was that it seemed like the tensioner pulley was pushing the blower belt rearward, toward the p/s pulley, whereas the "straight" portion of the blower belt was in alignment. I wonder if the tensioner is somehow not square? The funny thing is, I didn't seem to have this problem before r&r'ing the blower so I could install the header wrap. The blower mounting bracket that attaches to the header studs was not moved.

My blower pulley is an FFS pulley, but I don't recall any spacer and I'm almost sure it isn't already in there. I do have threads remaining outside of the pulley, but I'm not sure that there is 1/4" left, although it's close to that. A quarter inch would be plenty. I think that even if the tensioner isn't perfectly square, as long as the blower belt doesn't rub the p/s pulley it will be fine. Tom, can you send me the spacer?

[BlownMX5]

It seems like from what I'm seeing that the tensioner assy is not square to the engine, it's biased to the rear at the pulley. It also seems like if I could correct it toward the front, that it might make the belt tracking better. So my question is: should I even attempt trying to correct it? I already have a shim under each of the three mounting bolts to keep the tensioner pulley off of the p/s pulley. If I put an additional one under the bottom bolt, that should increase the angle of the tensioner so that the pulley is more toward the front. The problem I'm seeing with doing this is that it might cause some slight bending of the mounting plate because it would no longer be square to the three standoffs. Maybe move the top washer to the bottom so there would be none-one-two from top to bottom?

[Tom @ Fast Forward]

You said it was BRP stand-offs, is it their bracket or mine?

[BlownMX5]

You said it was BRP stand-offs, is it their bracket or mine?

If by "bracket" you mean the flat plate that the tensioner mounts to, it's yours.

[Tom @ Fast Forward]

Do you still have my stand-offs that came with the auto tensioner kit? If so, have you tried them or are they the same length as the BRP? The tensioner is flat to the plate and the plate should be flat to the stand-offs and it all should be square to the engine unless one of the standoffs is incorrect. If you don't have them anymore, I will send a set along with the spacer.

[BlownMX5]

Wow, I don't remember a spacer or getting new standoffs with the tensioner. It's probably just old-geezerism :drool5:. When I get home tonight, I'll check my "old parts cabinet" which is where the old standoffs should be.

[BlownMX5]

OK, I do have another set of standoffs, they are longer. The ones that are on the car are about 1-3/8" long, and the other set are about 1-5/8" long. One of them has a long stud still in it, I suppose that threads into the blower housing itself? Which ones are yours, Tom?

I can't tell if I have the spacer on the blower pulley. There is only about three or four threads exposed outside of the nut.

[Tom @ Fast Forward]

Mine are 1-5/16". The short ones. We did find once in awhile that a washer was needed.