Won't start after rebuild...

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dbr
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Joined: Tue Jan 14, 2014 5:05 pm
Your car is a: 1981 fiat spider
Location: St. Charles, IL area

Won't start after rebuild...

Post by dbr »

Hello All, I need help diagnosing a problem that may and probably does require multiple fixes.

First a quick background: I just finished a year and a half engine rebuild. I had some problems toward the end and because of time and money went the cheap way out. I just finished putting it all back together and it looks pretty and everything, but won't run.

Symptoms: At first it wouldn't turn over so I checked the starter and battery and all important connections. The starter was fine but the battery needed a new one and the new ignition connection had to be tightened. Now it turns over but won't start. I checked for a spark and I'm only getting a super weak random one. I checked the coil and that appears to be fine (1.8 ohms primary, 10,500 ohms secondary). I checked all my grounds and those appear fine as well. Now....the nightmare......I then checked the cylinders through the spark plug hole to see if anything inside was causing problems. All appeared fine, except the first which was filled with coolant!!!! :evil: :cry: I then checked the coolant and sure enough it had gone way down. So basically a filled cylinder and weak spark...

Some possibilities: I had a problem with the bolt that connects the head to the block (between two middle cylinders), afraid of ripping the thread I decided to temporarily leave it out. I recognized somehow this was also filled up with coolant. I'm not sure how the bolt and first cylinder could both be filled and not any other cylinders or how coolant could reach the bolt to begin with.

Does anyone have any possibilities on how I should tackle this engine? I'm just guessing I have a new crack or bad new gasket that's causing the leak. Also, the weak random spark is probably unrelated to the leak...I'm guessing. I'm on the verge of selling the beautiful car.....you get my wrath and exhaustion.
ORFORD2004
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Your car is a: 1983 PININFARINA
Location: Sherbrooke, Qc, Canada

Re: Won't start after rebuild...

Post by ORFORD2004 »

Head gasket first and use stud for head bolts You are suppose to use new bolt everytime because they stretch.
Allison got both or check ARP Bolts for the studs. Also check base and head, they have to be flat REALLY flat.
Use a tap in each bolts holes.
Shadoobie
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Re: Won't start after rebuild...

Post by Shadoobie »

I'll start by saying that I've rebuilt my engine twice when it was my only car and pulled the head of at least a dozen times between, so I feel your pain. Trust me, the end result is worth it. The most likely reason the cylinder is loaded with coolant is that most of the head bolts run through the coolant passages in the block. When you left the bolt out it allowed coolant to get in a lot of places it shouldn't have. Just pull the head and be sure to tap the bolt holes out 4-5 times with the head off. Only the 83-85 models use stretch bolts, all others are fine to reuse. However, it is VERY important to clean the threads of the bolts and visually inspect them for stretching due to over tightening. If they don't look perfect to the naked eye replace them. As for the weak spark, if your coil and pickup are fine I can practically garauntee you inserted your distributor out of time. It's very easy to do and I've done it almost every time I've removed it. Just make sure that when the engine is set to TDC the rotor is pointing directly at the number 4 contact in the dizzy cap. It sounds like you're very close to completion, don't give up now! When you're cruising it'll all be worth it. :)
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dbr
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Your car is a: 1981 fiat spider
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Re: Won't start after rebuild...

Post by dbr »

Thanks so much for the help.

What I did: So I got a new head gasket and retimed everything as best as I could. I set the distributor cap so it was touching with the fourth cylinder contact inside. I also checked:
All my grounds and wires under the dash.
NGK spark gap (.035).
Battery: 12.4 off and 10.4 while starting.

It still doesn't run, it sputters at times but won't start. I checked my cylinders again and they are dry but now I have white oil in my cams and the coolant is disappearing. I'm guessing that now somehow the oil and coolant are mixing. I'm afraid it's through the head gasket again. When I replaced the head gasket, the block and head were fairly smooth just some wear from past gaskets made it a little bumpy. Could this be causing the oil problem?

If I can get it to run I can then worry about the white oil. I checked for spark again and I'm still getting a weak spark. Does anybody have any idea what could be causing it now? Thanks!

Also, does this wiring for the distributor look OK? this was the only wiring I wasn't sure about.Image
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phaetn
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Re: Won't start after rebuild...

Post by phaetn »

Hang in there. I've been through head gasket issues and they can be super-frustrating. When everything is done right these engines can be surprisingly reliable, so don't sell the car yet!!! :)
dbr wrote: It still doesn't run, it sputters at times but won't start. I checked my cylinders again and they are dry but now I have white oil in my cams and the coolant is disappearing.
Milky oil in the cams definitely means coolant is getting in there. That's not good news and will eventually corrode bearings. By coolant disappearing I assume you mean that levels are going down. Is this left over from before or still happening? If this is happening even *without* it running it means coolant could be dribbling where it shouldn't even without the added pressure from heat or combustion. It sounds like you had this happen with cylinder #1. (I once had a head gasket fail so badly that I could pour coolant into the rad then hear it dribble into cylinder #3. Very bad news and can lead to a catastrophic hydro-lock).

It would be very difficult for an engine to start if you have a coolant leak even under cold conditions as it will interfere with the air/fuel mixture. Sometimes coolant leaks only show up once the engine heats up and the block/head/intake expand at different rates or a hairline crack widens, but this is normally seen by white exhaust and a rough sounding engine, but it will start.

You can get a pressure test pump for your cooling system and makes sure it holds pressure without dropping when engine is cold. If you have head gasket issues these are worth their weight in gold. Also, our cars are odd in that coolant runs through the intake manifold so it's possible for coolant to drain into the cylinder from there, as well. (Crack in the intake/bad seal with the intake gasket, especially around the coolant passages.)

There's a specific tightening pattern for the head bolts, so having left some out is not good and can warp the head. There's no way you should try to start an engine without the head being properly torqued down as you won't get proper compression and it might affect the integrity of the gasket. Also, as previously mentioned, with this Fiat engine some coolant will come up through the bolt holes and will contaminate the oil and can get into the cylinders since the head gasket isn't clamped properly. I'm not sure from your account if cylinder #1 was filled with coolant before or after you had taken the bolts out.

Once everything is buttoned back together you could also do a compression test on the pistons to make sure the new head gasket you installed is okay (cranking it without trying to start it). Ideally a compression test should be done on a warm engine with the throttle wide open, but you can test even cold. Anything over 100psi in each cylinder should be fine to get it running, but a big disparity between cylinders can show a head gasket problem.

Like Shadoobie I've had the head off a bunch of times; coolant leaks are a real pain, but hang in there. On the same 1.8L block I've tried two different heads (one taken to a machinist), two different intakes, I've tried MLS and regular gaskets, and use Allison's stud kit instead of the stock head bolts for extra clamping force. At one point I was getting ready to even buy a whole new engine, I was so frustrated. Eventually I got it. Just be methodical and keep going. These engines aren't very complicated.
I'm afraid it's through the head gasket again. When I replaced the head gasket, the block and head were fairly smooth just some wear from past gaskets made it a little bumpy. Could this be causing the oil problem?
Perhaps. The gasket is meant to make up for imperfections between the mating surfaces, but there's only so much it can do. You want to try with surfaces as smooth as possible and never reuse a head gasket. Can you see where the original failed? Why do you think you had coolant in cylinder #1? Were the head bolts loose up front? If you had standing coolant in the cylinders at any time it will eventually drain past the piston rings at the split and into the oil. You will have to change the oil and filter to get rid of it, probably twice. If you have had a lot of coolant mix improperly you will see your oil level rise at the dipstick and have coolant drain first from the pan since it will sink to the bottom. I'm not sure if it will be an issue, but if the level is too full because there is coolant in there it could also over-pressurize the oil system and blow a seal, so don't run your engine if your dipstick level is too high.

I'd suggest a compression test as a next step if you think everything is assembled correctly. Do it with all sparks plugs out to make it easier on the engine when cranking and to prevent hydrolock if there's still a coolant leak. Unless compression is decent the engine won't run right, no matter how good your spark is. Next step is a coolant pressure test. This can help identify where a coolant leak is occurring and why. A cheap inspection camera can be good in these situations so you can stick it down the plug hole when the cooling system is pressurized, as well as down the intake when the carb is off.

Spark is a separate issue and I can't help you with that since I don't use a stock distributor.

I hope this helps. Keep at it!

Cheers,
phaetn
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dbr
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Re: Won't start after rebuild...

Post by dbr »

Thank you so much phaetn! Your post really helped me.

I've been checking everything that I had taken apart, over again to make sure I assembled everything properly and noticed that I wasn't getting fuel returning back to the tank. Fuel wasn't going through the fuel pressure regulator. Shouldn't the fuel pressure regulator be allowing fuel through when it's cranking? Would this also not let it start? I noticed several others had a similar problem but their engines ran and they could check the regulator by plugging the return line and checking the pressure. How should I diagnose it when it doesn't run?

I temporarily unplugged the hose that goes from the tank to the pump and dipped it into a small regular gas container. The fuel that's in my tank is really old and I didn't want it go through the engine, so I temporarily set up my container method. I doubt this would have any effect on not getting fuel passing through the fuel pressure regulator. thought i should mention it just in case.

I'll check my compression and pressure in my coolant system and report back!
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dbr
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Re: Won't start after rebuild...

Post by dbr »

Hello! It's been such a busy summer that I haven't had time to work too much on my Fiat. But here is my very late update.... I double checked my ignition system and found the spark plug gaps were too large plus I bought some knew pieces that I thought at the time were the problem when they weren't. Now I have good spark (almost entirely new ignition system), so i know that's not the problem. I then checked the air and fuel systems. Air seemed perfectly fine but there was a huge crack in the fuel line right before the pump. Basically the pump was sucking in air rather than fuel. I fixed that and double check all injectors as well as cold start valve. Everything is fine in the fuel system now. So I'm 99% sure the fuel system, ignition system, air, timing, wiring and grounds are perfectly fine. This is what drives me nuts. I'm replacing perfectly fine parts and rechecking perfectly fine things over and over!!

I then checked compression and all the cylinders but number 1 were at 110-115ish. Number 1 was at 65-70. The head gasket is new and I don't recall there being any sort of anomalies around cylinder 1 that would have caused bad compression. It turns over and every now and then makes a sound like it ignited(turning...turning..pop..turning..pop,pop...) Could the compression in 1 cause it not to start? I have a feeling its something else as well? Any ideas on what I should do?

I also checked the coolant pressure and found a small leak, although I don't think its the only one. But the coolant isn't important now. I just need the engine to turn on to help boost morale!
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dbr
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Re: Won't start after rebuild...

Post by dbr »

Also, real quick. I also did a wet test on compression 1 and it went up to 115-120. Now I'm afraid that I didn't do dry test properly. Before I even consider replacing piston rings how can I double check they are the problem? Thank so so much for any help.
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dbr
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Re: Won't start after rebuild...

Post by dbr »

OK....so here's some more news... Since I didn't know what to check next or what could really be causing the issue, I decided to recheck everything all over again. I tried to start her and realized the fuel pump which I had recently worked now for some bizzar reason wasn't working. I checked to make sure it was getting voltage and it was, so basically it's burned out.

I then checked the injectors. I unplugged the red wire from the starter as I didn't want to burn it out like the fuel pump and measured the voltage at each injector and cold start valve. None of the injectors were getting anything but the cold start valve was. This makes me think that the fuel pump burned out because the fuel injectors weren't working. Could this be? And could unplugging the red wire of the starter stop the voltage from going to the injectors? I can't see why it would considering the cold start valve was getting voltage.

Any ideas would help, thanks!

btw....does this timing for the crank seem right? Believe me I've tried every possible position but just wanted to make sure i was getting it right. thanks! Image
spider2081
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Re: Won't start after rebuild...

Post by spider2081 »

I unplugged the red wire from the starter
Is this the red wire that pushes on to the starter solenoid? The green wire from the battery, the brown wire to the ignition switch and the wire connecting the alternators output should all be connected to the starter solenoids battery stud.
I checked to make sure it was getting voltage and it was, so basically it's burned out.
When you made this test were both the pump wires connected to the pump and the measurement made on the pumps terminals. If not you may not have checked the pumps ground connection or a poor connection between the FI fuse and the fuel pump. The fuel pump ground is usually in the trunk located on one of the drivers side tail light mounting studs. This ground is a common problem with FI spiders. Many people have relocated the ground to clean metal and use a machine screw and nut making a secure ground.
None of the injectors were getting anything but the cold start valve was
The injectors and the cold start valve are different outputs of the dual relay. I'm thinking the cold start valve only has power in the "start" position of the ignition switch. The injectors should have power in the "Start and run" positions of the ignition switch. The FI computer (ECU) provides the ground to activate an injector. The dual relays fuel pump relay is activated by a switch in the Air Flow Meter so it needs to be plugged in and the large air hose needs to be connected between the throttle body and the AFM.

Are you using a Bosch FI troubleshooting guide to assist your testing procedures??
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dbr
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Re: Won't start after rebuild...

Post by dbr »

Thanks for the advice....I have been using the trouble shooting guide and everything seems to be working out fine. I double checked the fuel injectors with a noid light and I got a very VERY faint flicker. Is it meant to be super faint? This rules out the relays or ECU. I added an additional ground going from the intake plenum to the body, just in case the grounds were an issue. If it shouldn't have a faint flicker what could be causing it...any ideas?

I checked the voltage at the fuel pump when it was all wired together. So I am fairly certain the fuel pump is bad. Pitty, as now I'm taking steps backwards, adding costs!
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dbr
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Re: Won't start after rebuild...

Post by dbr »

Ok, so the search goes on. I took out the fuel pump and hot wired it to 12v and it didn't turn on. So it is definitely bad. It was working perfectly fine before so I'm guessing there is a reason why it died and it's probably a symptom of whatever is not starting my car. I looked into the faint flicker of the noid test on the injectors and found out that it should be faint but not too faint. I checked my double relay again and can here it turn on. So i think it's fine.

My current guess: I measured 8.7v going to the fuel pump (measured it from the green and black wire at the relay). This is low as it should be 12v. So I'm also thinking the injectors are getting very low voltage as well, not letting them open all the time and hence killing the fuel pump (over pressurization). Ideas?....
Shadoobie
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Re: Won't start after rebuild...

Post by Shadoobie »

In my experience, most instances of low voltage are a result of bad grounds, especially if the car has been sitting. I would highly recommend going through the fuse box with a wire brush (ideally on a dremel) and polishing every brass connector. I've completely resurrected the electrical system on old Fiats this way. I would do the same for the ground pods inside the engine bay on the front fenders. They may look okay, but if the connections aren't reflectively shiny then they're not doing their job.
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