89 Blazer Wouldn't Start Now Running Rich

[Markgc]

Thank you for your replies. I will take a look at the thermostat

Regarding aligning the distributor, the oil pump does sound like it could be the problem I wonder if it is necessary to use a screwdriver to adjust the position of the oil pump slot so that the distributor can be pushed all the way home.

I will take the Blazer for a 50 mile interstate drive and see if there is any oil leaking around the distributor. This engine is pretty leaky anyway - it is an original engine with 260,000 miles - not bad eh. The crankshaft rear oil seal is a bit leaky now but it keeps on going.

How did your igniton timing experiments go? I used to advance my English engines to get more top end power at the expense of low end torque.


Mark

[Rmbodie]

My timing tinkering seems to have worked out well . My ultimate goal was to keep the engine from running hotter than normal on road trips . Since I am not using factory original equiptment with lots of sensors removed , the computer controled timing does not seem reliable . I think I found its sweet spot . It cranks very easy, The temp stayed the same while pulling my trailer with ATV , and it had tire ripping torque off the line . Previously , even through the winter months , the temp would get up around 220 . I have a 160 thermostat and back up guages . Now it stays around 180 . The timing is the only thing I changed . Rob

[Markgc]

What sort of distributor do you have and how is the advance and retard taken care of. Mine is done by the computer and knock sensor. In the old days it was done by springs, weights and a vacuum diaphram.

I have an electronic ignition module on my Triumph Boneville that has a built in advance curve basesd on engine rpm.

Did you advance or retard your base timing?


Mark

[Markgc]

Hi Rob,

I looked at your post more closely and I imagine that you are running the stock distributor, ECM and EST module which is attached to the firewall.

Have you put a strobe on the engine and seen what sort of ignition advance you are getting at different engine rpm's. I could compare them to what I am seeing if that would help.

Sounds like your rtming was off a bit and causing the hot running. Be careful that it isn't too far out as it could casue a burnt out valve or holed piston. Well that is what used to happen in the old days. The fact that your engine is now running cooler is a good sign.


Mark

[Rmbodie]

Since I converted to carb , My throttle position sensor is not connected so the computer doesn't know it is revving up . I know what the knock sensor is supposed to look like and where but I can't find it . I did not have any luck with factory base timing . When running the strobe on it , I noticed that when I rev it the timing retards briefly before advancing , since all the parts are still connected to the stock ignition parts as you mentioned ,I basically have it set by ear and seat of the pants . Its really impressive to light up these big tires without braking it down first but I still hear a brief moment of spark knock when it shifts gears under heavy thottle . I am looking at doing away with the stock computer completely with an MSD igition system. Rob

[Markgc]

There are two connectors on the distributor. One goes to the coil and the other sends rpm information to the ecm. I don't know if the ecm needs to use the tps at all.

I will take a look at my manual and see if I can find out where the knock sensor is located

The MSD system sounds interesting. I will have to take a look at it on the web.


Mark

[Rmbodie]

My manual (haynes ) says to tap on the exhaust manifold at a certain place and listen for the rpm to change . Nothing happened , I searched the entire engine block . I think it was removed before I got it .I have a couple of wires with no ends attached. Anyway, I am happy with the way it is working right now , except at the pump . My carb is calibrated for performance but I am going to re-jet it for economy per Edelbrocks instructions .How did yours do on its first week back on the road ? Rob
P.S. Lets go to private messages so the mod won't fuss .

[Markgc]

Here's a picture of my old damaged distributor. The metal coil former to the right of the white wire is fractured and hanging down. It is resting on top of the ignition module