WICruiser

As previously posted I had a warm up flat spot (lean) that now seem sto have disappeared and been replaced by a timing belt tension warning.

I pulled the front end of the engine apart this last weekend, confirmed the tension was a little low (out of the window on the Kempf tool) but could not find anything else that looked out of wack. The belt is tracking near center on all of the sprockets/puuleys, the water pump shaft is flush with the outside of the pulley, no leaks (coolant or otherwise). The tensioner (rebuild standard) was a little low on lube.

I reset the belt tension, about 1/2 turn on the adjustment screw, filled the tensioner, and thought I was good to go. But on the shake down test drive the belt tension light came on, I am guessing only 3-4 minutes after starting - probably about the time the time delay kicks off.

I am pretty sure I double checked the warning circuit connections, both inside and outside of the lower cover.

Strange thing is that ever since I had the tension warning (last two trips - one before and one after re-tension) the flat spot during warm up was gone.

They maybe totally unrelated but any ideas would be appreciated. I hope to pull the passenger side cover next weekend and double check the tension and tension circuit. I hope I don't need to pull all of the front off again, its not hard but it sure takes time.

cold_beer839

Age/miles of the belt?

underdog928

What brand belt do you have in there and how long (both miles and time) has it been in there?

Also have you retensioned it? If so, how long ago? You do need to check the tension around 1,000 miles on a new belt.

On my '85 it seems that I have to set the tension on the high side of the Kempf tool, just past the notch, otherwise my t-belt warning light comes on when I rev the engine to over 4K. Others have stated similar results.

WICruiser

I believe it is a Gates belt. Installed by me in 2005/06 when I bought the car and refurbished the belt, tensioner, etc. and did an intake refresh. Approx. 1500-2000 miles since then. Runs about 400-600 miles a year.

Retentioned the belt last year due to warning. Assumed it was the retention after installation.

A few weeks ago tension warning came on again. I was concerned that there was something moving so I removed all the covers and looked at everything I could see without removing TB related parts.

Set tension at TDC #1, confirmed cam positions, rotated by hand after and rechecked.

underdog928

Well if this belt is really getting loose after repeated retensionings, there could be something wrong with the it. Or maybe there is something wrong with the Kempf tool and you're not setting the tension tight enough.

Since your "flat" spot problem seems goes away with a retensioned belt, maybe it's time to tear it all apart and recheck everything, pulleys, gears, belt, everything. Also, while you are at it (ever hear that before?) replace your belt with a Gates Racing belt. I just did and am very impressed with how well it's built. It seems much stronger than the Porsche belt and should not need to be retensioned as much. We'll see.

cold_beer839

Install a Porkensioner and TB, then replace TB every 5 years of 50k miles. That's what I did on my GTS.

The stock tensioner and warning light system is JJJJJJJJJJJJJJJUUUUUNNNNNNNNNNNNNNNNNKKKKKKKKKKKK

zekgb

Bill Ball and I chased an intermittent tension warning on my 85 for a couple of weeks and we finally found that the spade connector at the end of the center cover plug had become loose and was causing the warning circuit to lose continuity to ground when the car was in motion, even though it checked out fine in the garage.

blown 87

What do you base that on?


I have a PK tensioner on my car, but to call the stock set up junk is wrong.

DuncanR50

Unless his Kempf tool was left out in the rain and rusted up, that's not the problem.

John Speake

Set the tension to the tight end of the Kempf tool window.

AO

A quick check would be to check for continuity between the the tensioner warning plug and ground. It should be closed. If it's open, then either the tension is low, or something is messed up with the TB.

If it is closed, then you may have a short in the harness and the can be checked by doing hte same proceedure on the harness end to ground.

Since the belt was installed about 5 years ago, the belt is at the end of it lifespan - timewise. Obviously you're nowhere near the 50-60k miles mark. On the '87 I just sold, it too had a TB warning light come on a few times. The belt was about the same age as yours, 4-5 years old, and similar to your it too only had a few thousand miles on it - maybe 10k. I tensioned it to spec, but it still threw a light. I cannot confirm the brand, but I think the belt was just tired. I bit the bullet and bought a PorKen Tensioner and Gates belt for it and now it should be good for several years.

Mrmerlin

there should be ground continuity at all times unless the belt tension gets low then the ground circuit is then broken by the spring assist on the tensioner pushing the contacts apart.

To test the system simply unplu8g from the front of the timing cover then the light should come on in about 3 mins .
shut off engine reconnect the wire start it up light should stay out.
BTW you need to drive the car more than 600 miles a year

for the OP was the water pump ever replaced and with what kind of pump new or rebuilt??
I chased a similar problem with my 88 and it wound up being the waterpump bearing moving this was with a rebuild,
The belt would be Able to be tensioned properly then after running the warning came on again,
after 2 times of this i replaced the belt and pump
then I got a new Laso no problems since

AO

MrMerlin is correct... My bad. Hadn't had my coffee yet.

Fixed.

WallyP

The belt tension warning is set by loss of continuity to ground. Check for continuity to ground at the connector on the belt cover. If there is no continuity to ground, possible causes include a poor connection at the spade connector or a broken connector strip on the tensioner arm. The metal strip was replaced by a wire on later cars.

SteveG

+1. He didn't say it came on each time at 3 min, but he did say it did it once. 3 minutes after start is the system delay, so I'm betting there is a continuity problem. Low oil in the tensioner should not cause a light.