Problems starting?

[sthmstr]

Ok so workin on a 7mgte for a guy. I replaced the head gasket for him (wouldn't go for the rebuild I recommended, but whatever. Not my car)

Anyways, it woulnd't start and sounded like an issue of timing. I checked and rechecked the timing belt and position, only to find that I had the CPS clocked wrong. After changing that it now will turn over but won't idle and immediately dies. If I floor the gas it kind of bounces like it wants to die and backfires.

Is this still timing or another issue?

At TDC I have crank mark set to 0* and both cam gear marks aligned with their marks almost perfectly. The CPS gear hole is ligned up to the mark and I put it back in like the FSM said to.

Thank you all for your help!!!

 

[hvyman]

adjust the cps in a diff spot and try that. check to make sure your getting fuel and spark. pul the no1 plug and see if it sparks while cranking. even if your getting a misfire it should still start. ive seen videos of 7m's running on like 3 cyl. you need 3 things fuel/air/spark. air you can almost always cross out air, so your left with fuel and spark.

how is the condition of the wiring harness?

check for codes?

 

[sthmstr]

Cool thatnks for the info. I fiddled with the CPS some more and got it to start. The harness is pretty rough all over the car so wiring issues are sure to come up eventually.

Once I got it to start it would die if I brought the RPMs over 1k. I hooked backup the MAF and all the hoses and it seems to run ok now. Before I hooked up the MAF it threw me about 3 codes, now they are gone. Super wierd. Must have been the CPS all along.

Thanks for the help!

 

[jkendall86]

This sounds awfully familiar....I just did a HG on an 87 turbo 5speed....went to crank it and it turns over but no firing. Checked for fuel and spark, have both. Rechecked the Timing, TDC on the crank and cam marks are straight up....pulled cam sensor and made sure it was aligned properly...still no start...cranks, chugs sometimes, but no firing...what else should I check?

 

[hvyman]

adj the cps a bit in a diff spot. you can rotate it only so much like dist for ign timing.

op you were prolly get codes for unplugged sensors.

 

[sthmstr]

I just kept crankin on it ant it finally turned over. After workin on it for a while with just adjustin the CPS like hvyman said I got it to hols. It threw about 3 codes and after starting and stopping it a few more times they went away. Very strange.

 

[jdub]

Just to be sure, the CPS should look like this with the crank/cam index marks all aligned:

I would also check the IC piping rubber couplings for leaks....the 3000 pipe to TB rubber tends to crack and you can't easily see it.

 

[jkendall86]

Just to be sure, the CPS should look like this with the crank/cam index marks all aligned:

I would also check the IC piping rubber couplings for leaks....the 3000 pipe to TB rubber tends to crack and you can't easily see it.

I have checked all the air and vacuum connections, they are all tight. I have had them apart several times to get at the CPS and made sure they were tight when I put it back together. About the only thing I have not done is to open the CPS to look at the insides and line it up. I had taken the CPS off and reinstalled it previously using the method in the TSM, it started at that time. Are there any other connectors you think I should check? I have double checked all I can remember so I guess the only thing left to do is open up the CPS, which means to take off several things to get at it, hope I don't create a different problem....

Thanks for all the comments.

 

[jkendall86]

I have checked all the air and vacuum connections, they are all tight. I have had them apart several times to get at the CPS and made sure they were tight when I put it back together. About the only thing I have not done is to open the CPS to look at the insides and line it up. I had taken the CPS off and reinstalled it previously using the method in the TSM, it started at that time. Are there any other connectors you think I should check? I have double checked all I can remember so I guess the only thing left to do is open up the CPS, which means to take off several things to get at it, hope I don't create a different problem....

Thanks for all the comments.

Opened it up....the CPS was off, by what appears to be one tooth! Apparently when you install them, you must rotate it slightly from what is shown in the TSRM so that when it is inserted, it will rotate to the correct spot. Maybe a better way, is to take the cover off when installing it so you can look inside and make sure it is aligned when it is inserted...I guess I learned this the hard way....car runs great, started on the first crank!!

Thanks for the picture, it was a great help.

 

[jdub]

You're welcome...What happened to you is very, very common