So I had my spark plugs changed today. Also put in new distributor cap, rotor and wires.

I accidentally took out all the wires and then found on google the wiring is as follows:

#1- bottom left
#3 - top left
#2 - top right
#4 - bottom right

Problem is when it was done - my brother squeezed the metal tips inside the boot too far. Since he couldnt get it to come in contact with the spark plug tip - he cut the boot and then sealed it with electrical tape and zip tied it.

The car started right up and ran fine for 5-10 mins. Later in the evening when I tried to start it up - the car kept cranking over and under the hood there was some very very light smoke coming from near the plug boots.

Has it shorted out? If so, can I just got back to 1 old spark plug and 1 old wire for short term? The old set had the metal boots and the new set from FCP is rubber boots.

Please help. Thanks.

 

I would keep your brother away from the car. Just use the old wire and you don't have to replace the plug. As for not starting and smoke I think you have something else not installed right. Even with 3 cylinders the car should start OK but will idle rough. Re-check everything again.

 

Will do. Thanks.

Plan to do all the work myself from here onwards.

The plugs look different though. The old plugs have a "thread" interface while the new ones look a bit more fatter.

I am confused because he did start the car in front of me when it was done and it ran just fine. Later in the evening when I tried starting is when all this happened. Could the wire from #1 just have become loose?

 

OK sounds like there is something different here so you need to check out a few things . Are the spark plugs the same or are they the correct ones listed for your year/model and engine. If not get the correct ones and the same with the spark plug wires. Next the cap should have the wire/cylinder number on it . Make sure the correct wire goes to the correct cylinder. Take your time but make sure you have the right parts.

 

The cap does not have any numbers on it (the old was Beru and the new is Bosch). But based on different searches on google - I am positive my set up is right. Plus it ran smoothly in the morning just after change.

FCP's website says that this the rubber boots are the right ones for the car. Based on that I bought it. I will hook up the old aluminum boot wire on cylinder 1 and see if it starts. I will post back here.

 

the fat connector spark plugs, you can unscrew that fat connector and the threads are underneath. some spark plug wire sets want the fat tip, others want the skinny threads.

and yeah, keep that bro away from the engine, hah. electrical tape is in no way suitable for this, the heat from the exhaust manifold will melt it in short order.

the best spark plug wire sets for these cars are the bougicord brand ones, they are made to the OEM spec.

http://www.ipdusa.com/products/5554/...-plug-wire-set

 

So I changed out wire #1 with one of the old ones. It started right up. I let it run for 2-3 mins but it kept hiccuping every once in a while - very randomly. At high revs it was fine. Found the spark plugs were a little loose so I tightened them up. The car started right up and idled much better. After about 5mins it stuttered and then shut down. Started right back and idled smoothly. 5 mins later is stuttered again and shut off. Not it just cranks and wont start - it almost catches but cant seem to hold on to keep the car running (same symptom as yesterday evening). All connections are fine. Could the ignition rotor under the distributor cap be causing these issues?
The #1 spark plug had a little bit of oil smear on the first 3 threads when I took it out.

Little background: The car would randomly require longer cranking to start if I let it sit in the sun for 7-8 hours. However, it would start immediately if I let it sit overnight. Car never stalled out on me before this.
Since I had never changed the plugs, I decided to get it out of the way. And now this.

Please help. I am lost.

Edit: No CEL/error codes showing up on the dash.

 

Sounds like a heat related electrical problem. It could be the fuel pump relay or if you have it on a 91 the radio suppression relay. After the car stalls and you go to restart it can you hear the fuel pump "hum" for a few seconds as you turn the key to start. The other area would be the crank sensor above the flywheel. It may be the connector is corroded up or an intermittent wire . Start with the fuel pump 1st.

 

The fuel pump hums everytime I start the car. After I posted - I went back to the car and it started right up. Idled smoothly. I kept in "D" with AC on full cold, seat heating on, rear window defrost, high beam lights and radio - all of this for 7 mins (yes I had a stop watch with me ). Then the same in "R", then in "P". These were for 5 mins each.

Following this - I shut off the car - waited for 3 mins restarted it. Kept it in "P" and revved cyclically to about 1300 RPM then let it back to idle and then back to 1300 so on for 5 more mins. Didn't hesitate.

Again shut it off - restarted and let it idle for 2 mins Took it around the block. Accelerated "hard" (I like the car too much to abuse it - so by hard I mean about 2200 RPM) and then dabbed my brakes multiple times. It ran fine.

Came back - shut it off and restarted again after 2 mins. Let it idle for 15 mins without any load (no lights or AC etc.). It idles smoothly. The digital tach I installed ($5 on ebay ) shows me idling between 788-812 RPM. Every once in a while - it drops to 779 RPM but no lower.

In-tank pump was replaced in April '13. So was the fuel filter. I thought the radio suppression relay was eliminated in '89. Is that correct?

Anyways, based on the above - am I ok for now? I am just perplexed on how the car was running poorly first and now for the first 1 hour or so the car has run fine. It has better acceleration feel too after the "tune up".

 

Update: I took the car to a back road - doing 45 mph it started stuttering as if it was wanting to die out. Same symptom had happened when I first got the car - but it was a blown in-tank pump and clogged fuel filter. Both have since been changed (bosch pump & puralor filter).

Also, it seems to idle fine but if I stomp on the gas pedal in "P" - it stutters and then catches up. Having the AC on just worsens it. Gentle pressing on the gas pedal seems OK.

This problem had happened twice before - once during winter and then about 2 weeks ago. Both times, shutting the engine off and restarting cured it. Now it persists.

Also, I mentioned that I had to crank the car a little longer if I let it sit in the sun for 7-8 hours. When it did that - the first couple of seconds it would stutter and then even out and idle smoothly.

Are any of these linked? I thought spark plug changes were simple. This is just slowly turning into a nightmare.

 

Tried running it today with the AMM unplugged. It ran very very poorly - in fact it ran better when I plugged back the AMM

 

ok, that usually means the AMM is OK.

 

I have had the AC on full and high beams with seat heatin for the past half hour. The car starts bogging down when the temp gauge reaches the half mark. On cold start it revs smoothly.

When the engine is hot, pressing the gas pedal abruptly causes it to bog down/cough and then it catches up.

Why?

 

hard to say, but engine temperature related problems are often from a bad engine coolant temp sensor and/or its wiring. also could be air leak problems in the intake, really hard to say without seeing it. I'm assuming the battery/alternator voltages are OK? (should be like 13.8-14.2V when running, even with everything switched on).

 

Yes voltages are within range. Also no check engine light (even checked codes on ports 2 &6) after I cleared the 1-2-1 from morning.

Right now both are 1-1-1.

I did hear something funny though. There's a "hum" that comes on once the car starts warming up (past 1/4 th on the temp gauge).

Air leak in the intake - do you mean in the plastic tube that leads all the way past the AMM?

 

I mean the whole intake path, from the AMM to the intake manifold gaskets. any air leak in there leads to drivability problems.

 

How do I check for leaks in the non "tuby" parts?

Just have the engine running and squirt some water?

 

Swapped back to the old distributor cap to see if that was a problem. Nope that didnt do anything.

I did find that if rev the engine suddenly and keep my ear near the intake side of the engine - there's a whoosh/hiss during the stumble and then the car catches up to the actual revs. So it seems like an air leak/vaccum issue.

Manual inspection of the intake tube revealed no cracks. There are 2 things I did find though -
1. The hose that goes from the bottom of the idle air control to the other side of the throttle body (nearer to the intake) was chopped by the PO. However, its on there securely and there seems to be plenty of metal underneath for it to cause any leakage.
2. There is a hose on top of the injector rail (very top and on the drivers side - curves and disappears into a wire loom along the firewall) - that definitely cracks on it. What is the function of that hose? its the one in the image behind the line calling out "C".

| Repair Guides | Vacuum Diagrams | Vacuum Diagrams | AutoZone.com

The vaccuum sticker in the engine bay shows 2 wires from the purge canister to throttle body and then one from throttle body to flame trap. Those all seem fine.

The wiring to ECT also looks grimy but ok.
Again advice will appreciated.

 

test the ECT resistance at the ECU and ICU connectors (with the corresponding CU unplugged, of course), using a multimeter in ohms mode.

I think I just posted how to do this on this or a similar thread. ahh, here...
https://volvoforums.com/forum/volvo-...88/#post394811

if the engine is HOT (temp gauge in middle), that should be like 600 ohms at both the ECU and ICU connectors, relative to ground.

 

The ECT (Engine Coolant Temp sensor) has two seperate temperature senstive resistors, both go to ground. one is wired to the ECU (Fuel Injection computer) and the other to the ICU (Ignition Control Unit). remove the passenger kick panel, and the plastic side panel on the right side of the passenger foot well (just forward of the right door). behind that is the ECU. switch the ignition off, and disconnect the battery ground cable to be safe. remove the big connector from the ECU, and if you shine a bright little flashlight in that plug (on the harness side), you can see the pin numbers. use a digital meter in OHMS mode, put one lead on pin 5 (ground) and the other lead on pin 13 (ECT) and you should read about 2300 ohms if the engine block is at 68F, and as low as 1300 ohms if its 100F (its probably somewhere between these this time of year). plug the ECU cable back in.

the ICU is against the firewall behind the glovebox. unplug ITS connector, read its pin numbers. ohm meter, one lead on pin 20 (ground), and the other lead on pin 2 (ECT), you should see about the same resistance as you did on ECU pin 13.

if either of these is completely open circuit, the wire is broken. if its short to ground (0 ohms), there's an electrical short. any value thats wildly out of range suggests a bad ECT.

if you remove the ECT from the engine, and put it in 200F water (near boiling), it should be as low as 190 ohms, and at freezing (ice water), 6000 ohms, either pin measured to the body of the ECT.

How do I get to the ECU behind the glovebox? Do I have to tear apart my dash?

I thought that a bad ECT would prevent engine from starting properly when cold. My car starts perfectly fine when it's cold. Problems start when its all warmed up. Just curious...

Also, what would a bad fuel pressure regulator do? And finally, does the '91s have the radio suppression relay?