Running Rough and I cant get up to 3k RPMs

[tybucki]

I replaced the head gasket in my 91 GS last weekend and lost time during the repair. When I got the engine back in time and got it running again the engine began smoking, it's running VERY rough, and I can't get the car to 3K RPMs. I tried adjusting the timing with the distributor and there was no response. I'm not sure what's going on and would like any help anybody could offer

 

[PieEyedPiper]

1. Is the car currently in time?
2. Did you start or run the engine with the car out of time?
3. Compression test
4..
5...
6....

 

[tybucki]

OK so I tore the timing cover off and checked the timing marks again last weekend and found the crank off by 1 tooth. I reset the timing, again, and now I can get the engine over 3k RPMs but it's still running rough. I drove it around the block and found that when it gets near to the aforementioned 3k rpms it bogs down bad and starts to surge. If I keep it under 3K it drives ok but like I said its still kinda rough. Somebody told me it sounds like the cam and/or crank position sensors aren't working properly and I recently found that both of those sensors are integrated into the distributor. If I position the distributor where I can adjust timing by adjusting the distributor then I have no throttle response, if I position it so that I have throttle response then I can't adjust timing by turning the distributor. I'm really hoping somebody has seen or heard something like this before because I don't want to go out and buy a new distributor, throw it in and find out that it doesn't do any good.

 

[DSM pHrEaK]

First do a compression test and post the results. You keep saying distributor...do you mean the Cam position sensor? Never seen a dsm with a distributor. What you may have to do is tare into the front of the motor again and make sure the timing IS FOR SURE dead on. Could take a few picks and post them up. It sounds like it's still out of time.

 

[tenzoR]

id suggest doing a compression test

 

[tybucki]

The 1.8L 4G37 that came on some of the G1 DSMs has a standard distributor not the points type system found on the 4G63 and, according to the chiltons manual, the Cam and Crank position sensors are both integrated into the distributor.

 

[tybucki]

Ok so I got a compression test kit today and ran it 3 times per cylinder, here are the results

4- 170 165 166 AVG 167
3- 165 169 171 AVG 168
2- 168 165 169 AVG 167
1- 170 175 171 AVG 172

Keep in mind its a 1.8 so according to the compression and leak down test article in the forums posted by calan standard compression is 185 and the engine is 20 years old and has 283k miles on it. So if I had to guess I'd say that's some pretty impressive numbers right? I also noticed that while I was warming the car up most of the engine smoke was coming from up front i.e. near the exhaust manifold but after the car ran for about 10 minutes the smoke seemed to be coming up from underneath the rear of the engine compartment i.e. from the cat. So I'm thinkin... is it possible my exhaust valves are still open just a little bit when the fuel is sprayed in and the longer it runs the more fuel pools up near the cat where it then burns off when the cat gets up to temp? If thats the case then it would definately be an issue with timing right? I plan to pull the front apart in another day or 2 and see if the timing is still where I set it last weekend or if it's off 1 tooth again

 

[DSM1G90]

Excellent numbers for that 4G37 !

Have you done lifters since they are so easy to do? How's the ECU?

When you pulled the head, did you get the DIST put back in right? Get the belts all in, roll it around to see if all marks are good, then put the thing on TDC with no. 1 on compression, then see where the rotor is for the DIST, which should be close to the 6:00 o'clock position, or just after No.1 wire position since the rotor spins clockwise.

Just retime the belt to the marks (what I got to do with my 1.8 is do belts and pulley).

Ever thought of replacing the fuel pump, for 283K miles is also on that pump.

Also, 283K miles .. I would say that the CAT is all but clogged up. If you still have it attached, drill a 1/8" hole at the head of the cat to relieve the back pressure and that will make a total difference since the thing can now breathe.

Good luck- DSM

 

[tybucki]

Actually prior to the initial cooling sytem flush which lead to the coolant boiling over because of the bad head gasket the car was running great. It passed the local IM a few months ago so everything should still be working. I tore it all apart to replace the water pump before I replaced the head gasket and it ran just fine after that, aside from the boiling over coolant that is. I was sure I had the timing set right the week before last but it was off so I'm wondering if it didnt just jump that 1 tooth again you know, enough to let it still run but run bad.

 

[DSM1G90]

The 1.8 that I have was also running a bit sluggish but still driveable, but it needed a WP real bad as well.

I pulled the covers off and "voila!" - balance belt had busted, went into the timing belt and threw the thing off two teeth.

New WP and redid the timing (forget about the BS belt for now since when I did the retiming, I noticed that the tensioner pulley was pretty weak -bearing was thinking on being rumbly-) and back on the road again - thing will easily hit 100mph and could go on with no problems.

Now, got the new tensioner pulley and new belts. Gonna do it all over again.

Another thing: how's the cap and rotor - any carbon traces under the cap, per chance? For this has wonderful effects on performance since that spark loves to follow carbon traces...

Good luck-DSM

 

[98mitsubishigst]

keep messing with the distributor.. that's what my 1g needed

 

[DSM1G90]

keep messing with the distributor.. that's what my 1g needed

Nope, not really. Just do the same base timing procedures as you do with the 4G63: ground the ECU terminal and do the 5*BDTC.. You probably needed the TPS settings and the two idle settings done correctly for it to run right.

 

[tybucki]

Ok so as it turns out I was misinformed about the timing mark on the crank. I found the correct timing mark and took pictures to post later and set everything to correct time and proceeded to turn the crank by hand to verify that it would stay in time. Unfortunately I forgot to take the pencil out of the block that I had used to verify the oil pump was set up right and broke it off into the oil pan. Yay me. So I drive across town to get the only oil pan gasket in the city for my car and head back home. After I got the oil pan pulled, cleaned, reRTVed, gasketed and reinstalled I set everything back in time and put the T belt on and tightened down the bolt that holds the tensioner in place and the bolt head snapped off. Now I have a bolt broken off in my block and no way to properly secure the T-belt tensioner to the block. So I get to either A: Try to get my hands on an engine hoist and pull the damn thing apart and up to get to the bolt or B: Pull the damned thing apart and drop it to get to the bolt. The universe hates me.

 

[brandonwh64]

I hear you tybucki! I have a 420A engine doing the SAME EXACT THING! I have checked the timing numerous times, changed the crank sensor, cam sensor, fuel pump, fuel filter, ECU, and IAC and this car will still not run properly. Good luck with your car man! We all need it.

 

[DSM1G90]

and the bolt head snapped off

how much Ft-Lbs did you put on that bolt? Only need about 30fl lbs for that bolt..unless it was ready to bust in the first place.

Wonder, if there is a burr hangin out on that stud, that you can grab it with a needle nose pliers...grab it and turn the pliers to see if the stud can turn.

 

[ahaley1]

get a few easy-outs and an angle drill and hope for the best i had a situation like this once on a starter bolt i took a STEEL not rusty nut that was small enough to not weld to what the bolt goes into and fill it in with a good hot weld and use a wrench to take it out NOT going to lie its not as easy as it sounds sorry about your bad luck "story of my life"

 

[tybucki]

OK so at work yesterday somebody said "Why don't you just drill through the firewall?" so I did. Got the broken bolt out got everything lined back up correctly this time fired it up and it was still runnin like goat arse so I decided to play with the distributor postion again and now it won't start at all. Turned the distibutor one tooth at a time in the same direction more times then there are teeth on it and it never caught. Thinkin more and more the dist is goin bad so I'm thinkin I'll probly replace that next and hope the universe is lookin the other way for 5 mintes so I can sneak in a win.